two people talking to each other about the solar panels next to them

How the Trump Solar Panel Tariff Affects the Solar Industry

How the Trump Solar Panel Tariff Affects the Solar Industry


Written by qualified solar engineer Leonardo. Last updated:

Trump’s solar panel tariff was introduced in 2018, increasing the price of imported solar cells and solar panels by 30%. Since the import tariff is reduced by 5% each year, a 20% rate applies for 2020. However, the tariff does not increase the final price of solar systems by 20%, since it only affects panels and cells. On average, the solar installed cost increases by less than 10 cents per watt. Therefore, solar power remains among the best investments available for property owners.

For example, a 10-kilowatt solar system will normally cost around $30,000 with current US prices, before subtracting any rebates and incentives available. For a system of this size, the Trump tariff on solar panels will affect the final price by less than $1,000.

How Does the Trump Solar Panel Tariff Work?

According to the US Trade Representative, China was producing 60% of solar cells and 71% of solar panels globally by 2018. This was possible in great part thanks to government subsidies and low-interest financing for solar manufacturers. At the same time, solar panels manufactured in the U.S. were becoming less competitive against the low-cost imported panels.

To protect US-based solar companies and stimulate local production, the Trump administration imposed a 30% tariff on solar panels manufactured outside the US. The tariff was introduced in 2018, with a four-year duration and a gradual reduction of 5% per year. The following table summarizes how the tariff affects a 300-watt solar panel with a price of $100 during each of the four years:

YearSolar Panel Tariff (%)Tariff for a $100 Solar Panel (US$)

Since the tariff uses a percentage instead of a fixed dollar amount, it increases and decreases along with the solar panel price. For example, a 300W panel with a price of $110 would have a tariff of $22, even with the same wattage as the panel in the example above.

These numbers may seem small, but consider that home solar systems often use more than 20 panels. In this case, the tariffs on solar panels result in a cost increase of $400. Commercial, industrial and utility-scale solar projects are affected more, since they use thousands of panels. For instance, one megawatt of solar capacity requires around 3,000 panels. If each of them has a $20 tariff, the one-megawatt project becomes more expensive by $60,000.

As previously mentioned, the import tariff imposes a 20% fee on both solar panels and solar cells. This means manufacturers cannot avoid the tariff by importing solar cells and assembling them into panels inside the US. However, the tariff does not make full a solar power system more expensive by 20%, since the panels are just a fraction of the total cost. Keep this in mind when reading solar tariff news.

Does the Trump Solar Panel Tariff Affect the Federal Tax Credit?

A man accounting for his taxes

The US government offers a federal tax credit for solar power systems, which can be combined with local incentives. Federal solar tax credit information is very abundant online, but the most important facts you need to know are the following:

  • The incentive was 30% until 2019, and it has been reduced to 26% for 2020.
  • There will be another reduction tax credit reduction to 22% in 2021.
  • From 2022 onwards, there will only be a 10% incentive for businesses.

The federal tax credit applies for the full price of an installed solar power system, while the Trump tariff only affects solar panels and cells. In other words, the tax credit is much higher that the extra import tariff. You can also avoid the import tariff by using locally-produced solar panels.

Solar panels are still fairly expensive, but the federal tax credit makes them easier to afford. For example, a 6-kilowatt home solar system has a typical price of around $18,000. If the import tariff increases the cost by 8 cents per watt, you pay an extra $480. However, when you deduct 26% of $18,480, the federal tax credit is $4,805. The numbers may vary when you get offers from solar installers, but in this example the federal tax credit is 10 times larger than the Trump tariff.

Solar panels are worth the investment even with the Trump tariff. Paying 20% may seem like a lot when only solar panels are considered, but the price effect on a completed system is typically less than 3%. Solar panels are also getting more affordable each year, and a percentage-based tariff decreases along with panel costs.


  1. Office of the United States Trade Representative – Section 201 Cases: Imported Large Residential Washing Machines and Imported Solar Cells and Modules
  2. Solar Energy Industries Association – Solar Investment Tax Credit (ITC)

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A house with a tesla solar roof installed

Tesla Solar Roof Cost vs Traditional Solar Panels

Tesla Solar Roof Cost vs Traditional Solar Panels


Written by qualified solar engineer Aniket. Last updated:

Elon Musk has recently rolled out version 3 of Tesla’s roof tiles. Being one of the most innovative products of the world of solar energy, they have garnered a lot of attention and curiosity. Although there is no doubt about its aesthetic appeal, the biggest question will always be whether they make financial sense.

The company offer the cost of a tesla solar roof at $21-22 per sq. ft., which is already nearly twice that of other conventional roofing solutions. This makes most of us wonder if traditional solar panels on regular roofs make a wiser option. In the end, we find out that the tesla roof makes sense only if you must spend money on a roof anyway. For any other case, traditional solar panels are a more practical choice. Let us break down how.

How to Estimate the Cost of Tesla Solar Roof Tiles

A tesla solar roof installed on a customer´s home

Tesla Solar Roof (Source – Tesla)

Although there is the stated figure of somewhere around $22 per sq. ft., it is not a straightforward calculation. The main reason for this is that Tesla does not cover 100% roof area with solar power generating tiles. Tesla’s new solar roof is essentially a mix of solar tiles and non-solar tiles.

In a random case, these residential solar roof tiles may cover anywhere between 40 and 90% area of the roof. This could vary significantly based on several factors.

One reason this may happen is that the energy requirement is smaller than what an entire roof of solar tiles may generate.

Secondly, there are spaces on the roof where installing solar tiles does no good, for instance, besides vents or any other vertical structures. Another reason is when one side of your roof faces north and has a steeper angle. This part of the roof will receive negligible amount of direct incident sunlight. This would mean very poor power generation, and thus, would make sense to not install the solar roof shingles on that portion of the roof.

As such, you would have to figure out the roof area which will be covered using power generating roof tiles. Tesla has not provided what ratio of PV and non-PV tiles is considered typical in the mentioned cost. However, there have been examples where the Tesla solar roof cost went up to $35/sq. ft. If a major portion of your roof is going to be covered in power generating tiles, your cost obviously rises.

This means there is not really a straightforward way to accurately calculate the cost of a Tesla solar roof for your home. But some assumptions of percentage of PV tiles may get you a rough number.

Comparing with Traditional Solar Panels

an inside look into the tesla roof tiles

Suppose the solar roof tiles were to be compared directly with the cost to install traditional solar panels. At $5-$10, the traditional panels cost less than half per square foot as compared to how much a Tesla solar roof costs. This seems obvious, considering that the energy that is produced by one solar panel will be several times the energy produced by a single solar tile.

In such a case, although it is fancy to have a power generating and eye-catching roof on your home, it is always more practical to have traditional solar panels and save a few thousand dollars on your residential solar system.

But when it comes to a new home, the comparison no longer remains the same. In this case, we need to compare the cost of Tesla solar roof tiles with the combined cost of traditional panels and a traditional roof. A good, modern traditional roof costs somewhere around $15/sq. ft.

Adding that up with the cost of panels and the other costs such as wiring, installation, etc. you can see that the combination of a new roof and traditional panels easily crosses the Tesla solar roof’s benchmark cost of $22 per sq. Ft.

Here is a comparison table explaining the same, prepared from the numbers claimed by Tesla.

comparison table explaining cost differences between tesla solar roof vs traditional roof plus panel combination

Tesla solar roof vs. Traditional roof + panel combination (source – Electrek)

Net cost over 30 years



ExpenseSolar roofPremium roof + solar panels
Solar panels$0$29,681
Roof & site repairs$10,630$10,630
Purchase price$85,314$87,619
Federal tax credit-$15,727-$11,919

Value over 30 years


As it can be seen in the comparison, the federal tax credit received for the solar roof is also higher than the traditional roof + panels combination, since you receive no credit for the roof costs in the latter case. This shifts the case a little more in favor of Tesla’s roof, making it worth the initial costs.

Besides the differences in appearance and costs, there are some notable similarities in both the technologies. For example, it is interesting to note that the solar roof has a lifespan that is the same as the lifespan of regular solar panels. Thus the money saved from using solar panels and that saved by solar roof over 25-30 years will be the same.

Additionally, both the technologies have the potential of increasing the value of your property.

In the end, we know that the Tesla solar roof is not for everyone, in a time when some people still believe that solar panels are expensive. Even Elon Musk mentioned in a conference that the roof does not make financial sense for somebody who has a relatively new roof.

But the addressable market of people building a new home or looking for a new roof isn’t too tiny either, when there is no significant competition. This is probably why Musk expects to install over 1,000 roofs per week.


The main question we are trying to answer is: “For whom is the Tesla solar roof an ideal choice?” And although all the financial calculations matter, the first answer will always be enthusiasts of new and innovative technology. This includes but is not limited to the thousands of fans of the iconic company that Tesla is.

For all the remaining people, we have figured out that it makes sense to install a new solar roof if you are building a new house and need a roof installed anyway. This also applies to someone who needs to renovate his roof for reasons of age and deterioration of the roof. For those who have a good existing roof in place, it is wiser to go for traditional solar panels and save about half the money, that is, if money is in question.

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businessman looking over the climate change

2021 Climate Change Report – How Solar Energy Can Help

2022 Climate Change Report - How Solar Energy Can Help Combat Global Warming


Written by qualified solar engineer Aniket. Last updated:

Solar panels are one of the best resources that we have available to fight climate change. They are not contaminating, their energy resource is renewable and inexhaustible, they can be recycled, and every kWh of energy coming from solar panels is a kWh of energy that is not generated in contaminating facility plants that expel greenhouse gases.

All of these contributions made by solar power plants are valuable in our fight against climate change, but what is climate change and how is it affecting our planet?

There are thousands of planets in the universe, some with characteristics suitable for the existence of life and others so hot, so cold, or so toxic, that the existence of life as we know it may seem impossible. However, besides its ideal position with respect to the Sun, there is an extra component that makes planet Earth unique in our galaxy: the existence of the ozone shield.

This ozone layer is composed of the so-called Greenhouse Gases (GHG) that include water vapor, methane, nitrous oxide, ozone, chlorofluorocarbons, hydrofluorocarbons, and carbon dioxide (CO2).  The accumulation of GHG creates a layer that reflects the UV radiation and concentrates the incoming heat from solar radiation in the atmosphere of the planet. This allows planet Earth to keep its temperature levels within ranges suitable for living, that would otherwise be too cold for the existence of life.

This is a natural process called Greenhouse Effect, and it has occurred over millions of years. However, increasing the amount of GHG above normal values has a negative effect on Earth’s temperature because the layer becomes thicker than what it should be and heat increases radically, leading to high-temperature values with bad consequences for the planet.

Are We Responsible?

Carbon dioxide levels have oscillated around the 200 parts per million in our planet, historically reaching a maximum of 280 parts per million. However, since the industrial revolution, carbon dioxide levels have increased to astronomic values close to 400 parts per million.

There are a few possible causes for this radical change and we can see them as follows:

  • Solar irradiance fluctuations
  • Volcanic eruptions
  • Tiny pollution particles (aerosols)
  • Changes in the available amount of land and trees.
  • Increases in greenhouse gas emissions.

While solar irradiance fluctuations and volcanic eruptions are naturally occurring processes, all of the other causes are directly attributed to human activity. Therefore, scientists agree that there is no other natural source of explanation for this rapid increase in CO2 levels than human activity.

And it is not a surprise to jump to that conclusion when you take a look at CO2 emissions data from several countries. According to data from 2017, around 10 gigatons (Gt) of CO2 were emitted in China, over 5 GtCO2 in the US, around 2.5 GtCO2 in India and nearly 36 GtCO2 all over the world. Watching the time evolution of carbon emissions from 1960 to 2017 leaves no doubt that we are the cause of climate change.

What Are the Consequences If We Do Not Act to Stop Carbon Emissions?

According to NASA, since 1900 the temperature of the Earth has increased 1°C. However, if global temperature increases over 2°C, there may be no going back, and the effects of climate change would be unavoidable.

chart to show how the global temperature has increased over the years

Global Temperature Rise (Source – NASA)

Increasing Earth’s temperature has several consequences for us.

The first, and one of the most dramatic consequences, are rising water levels. Recent studies from NASA on Greenland and the Arctic have demonstrated that continental-size ice formations are melting down due to the excess heat, and they have reduced nearly 10% in the last 30 years. All of that melted ice goes to the ocean and is now attributed to sea level rise in the US and all over the world, even reaching distant locations like Indonesia, China, and Japan.

Unfortunately, 2015, 2016 and 2017 have been recorded as the hottest years in recent history, which is bad news for Greenland’s ice that has been continuously melting over the last decades. In order to better understand the impact of climate change on sea level rise (and therefore floods in coastal regions across the US) you can watch this amazing report from CNN that explains this further

Moreover, other consequences of climate change are related to longer and harder droughts across the world, which also leads to less productive and less nutritious crops. With the Earth population’s Increasing without control, drought seasons will have a significant impact on the food supply of our nation, increasing the cost of food and possibly leading to famine in poor countries.

Destruction of the ozone layer is also a secondary consequence of climate change. As heat concentrates further in the atmosphere, the contrary process occurs in the stratosphere. As the stratosphere cools down, and the atmosphere heats up, there is a warming-cooling dynamic effect that causes ozone loss. Due to this ozone loss, the ozone layer depletes and leaves the ground wide open for ultraviolet radiation to reach our atmosphere. This can easily be seen in the ozone hole in the South Pole.

two side by side images to show the difference in the the ozone hole

The Ozone Hole (Source – Union of Concerned Scientists in the USA)

Heat waves are also a direct consequence of climate change. They mean more frequent wildfires, longer droughts, and deaths. Actually, heat waves are considered one of the major causes of death from natural disasters, mainly due to heat strokes that are caused because the human’s body is unable to cool itself down due to the high humidity in the atmosphere.

map chart of the usa to show the total heatwave days in the us

Increase in Total US Heatwave Days (Source – Center for Climate and Energy Solutions)

Stronger hurricanes, storms, snowfalls, hailstorms, and sandstorms can also be attributed to consequences of climate change that will intensify due to radical temperature changes.

These consequences and others may not last centuries to become real, but some may only take a few years.

Who’s Fault Is It?

According to the IPCC report from 2014, the energy supply sector accounted for almost 50% of all GHG emissions, making it the largest contributor to global GHG emissions. Despite the Kyoto Protocol, GHG emissions of this sector increased 36% between 2000-2010, where the major contributors were CO2 emissions from coal (43%), oil (36%) and gas (20%). Here you can take a look at the contributions from these sources over time.

chart to show the energy supply sector ghg emissions by subsectors

Energy supply sector GHG emissions by subsectors (Source – IPCC)

Moreover, the report emphasizes that transport is another important sector which contribution accounts for almost 23 % of total energy-related CO2 emissions. To reduce the effect of this sector on carbon emissions, it is necessary to lower the energy intensity by enhancing vehicle and engine performance and substituting oil-based products by natural gas, bio-methane, biofuels or hydrogen.

Is It Too Late to Stop It?

The Fourth National Climate Assessment Report from the U.S Global Change Research Program, released in November 2018, has announced an alarming top date to make a significant impact on carbon dioxide reductions. According to the report, if CO2 emissions are not cut 45% by 2030, then it will be unavoidable to reach 1.5°C increase in Earth temperature.

A range between 1.5°C and 2°C was established in the Paris Agreement, however, reaching 2°C would already mean reaching to worst climate change consequences, therefore, it cannot be seen as a threshold.  Besides, the report concludes that by 2050 carbon emissions must be cut 100%, making a complete transition to renewable energy sources.

The report addresses remarkable impacts that have already been seen in American ground related to wildfires (Northwest), droughts (North and Southwest), hurricanes (South), floods (South East), water and transportation failures due to heavy snow, heat waves, and soil erosion (Midwest).

Based on these results, the US report focuses on the imminent need to reduce the amount and speed of future climate changes by reducing GHG, replacing CO2, and emitting fossil fuel energy sources with zero-emission technologies such as geothermal, wind, biofuels, hydro and solar.

Solar Energy – A Source of Light to Fight Climate Change

As one of the most commonly available, accessible, and feasible renewable energy options, solar panels are one of the main drivers in the reduction of carbon emissions across the globe.

We can estimate the reductions in carbon emissions by using solar panels thanks to the IRENA calculator. The latest data available on the tool is from 2014 and still we have an idea of the great contributions of solar energy into the market.

Experiences in the US have shown that around 17.5 million tons (MT) of CO2 can be avoided which translates into 22,000 GWh of electricity. China also made incredible contributions that reach 20 MT of CO2, and 25,000 GWh of energy injected to the grid.

Germany was the greatest contributor in that year with 29 MT avoided and over 35,000 GWh produced. This can be translated into 18 million tonnes from coal sources, 3.38 million from natural gas, and 9 million from oil sources.

The contributions from other countries like Japan, Italy, Spain, France, UK, Australia, India, and South Korea were able to amass almost 80,000 GWh together and 63 MT avoided CO2 emissions for the environment.

As solar energy keeps growing every year, these numbers have already surpassed the estimated values. As a reference, nearly 177 GW of installed capacity were available in 2014, but in 2017 around 402 GW of installed capacity are available worldwide. Meaning around 130 % of growth in only 3 years.

bar chart to show the global solar pv capacity by country or region between 2007-2017

Source – Global Status Report 2018 REN 21

The Use of Residential Solar Panels

One of the best ways that most of us can contribute to the fight against climate change is for more people to hire solar companies to install solar panels on their homes. Solar energy presents a set of advantages that can be used to offset carbon emissions and investing in solar for your house will also help your wallet.

Using solar lights and other solar powered home products all help towards reducing our carbon emissions. Whilst the reductions are minimal, it’s a case of every little helps and when done at large scales it really can make a long term difference.

Solar Panels Do Not Contaminate

The main drawback from using fossil fuels as a source of energy is that to generate electricity, we need to burn them, which leads to high carbon dioxide emissions that contaminate our planet and accelerate climate change. You can see below, the amount of CO2 produced when a fuel is burned as a function of the carbon content.

image to show the pounds of co2 emitted per million british thermal units of energy

Pounds of CO2 emitted per million British thermal units of energy (Source – Energy Information Administration)

On the contrary, one of the intrinsic advantages of solar panels is that they are a sustainable and clean source of electricity production, therefore they emit zero CO2 because the process to generate electricity is done at the molecular level without the need to burn any component with carbon.

Solar Panels Generate Renewable Energy

Fossil fuels are sources of energy that exist because of decomposed plant or animal matter at high-pressure levels that accumulate underground over thousands of years. Since planet Earth has millions of years of existence, you can imagine the amounts of accumulated matter.

However, despite their abundance, they are still exhaustible sources of energy. In other words, once we extract them all, there will be no more electricity. And it takes millions of years to accumulate the amount of fossil fuels that we will consume in 200 years.

The Global fossil fuel reserves left are estimated to be 114 years for coal, 53 years for natural gas and 50 years for oil. When you compare that, with the 1 billion years of clean available solar energy that we still have ahead of us, sounds like there is no sense to keep pushing on limited sources of energy that will be over in only a century. Since solar energy is inexhaustible, there is no need to replace it with another resource in the future, assuring a safe and clean source of energy for the centuries to come.

Actually, solar energy alone is enough as to provide the entire energy consumption of the world almost 100 times which could be supplied using only 1% of surface area from the Sahara desert.

Solar Panels Last Over 25 Years

Fossil fuel electricity consists in burning large amounts of carbon sources to generate the energy that the power grid demands through a thermodynamic process. However, it is necessary to keep a constant cycle of extraction of the fossil source. People generally focus on the carbon emissions from these sources at the moment of electricity generation, but they seem to forget one thing, the effects during the extraction process.

For instance, coal is generally extracted from the upper portion of the Earth’s crust in ore mines, recovering the coal from the mine using shovels and bulldozers to do the hard work. When mining activities are done, exposed rocks are left behind containing the Sulphur-bearing mineral pyrite. This mineral reacts with water and air to form sulphuric acid and dissolved iron. Then, when the rain comes, the compound transforms into diluted acid that falls into the streams and nearby rivers.

Deforestation is also another devastating consequence of coal mining, this is caused by mountaintop removal for the mine. Mountaintop removal mining also releases large amounts of GHG emissions through clearcutting and burning of trees which can represent close to 7% of a coal power plant GHG emissions.

On the other hand, the solar industry has focused on providing reliable quality standards to manufacture solar panels that incentivize the market to install PV systems at residential, commercial or utility-scale. One of the basic standards from any PV system is that the array will last at least 25 years.

This translates into 25 years where you do not need to worry about electricity generation and where no additional environmental damage will be done to continue the production of energy.

Solar Panels Are Recyclable

When modules reach the end of their useful life, something must be done with the solar panel wastes. Considering just burning them down or throw them away into a pile of waste wouldn’t be exactly environmentally friendly, right? Especially because some of them could even have toxic components like cadmium telluride, indium, gallium and selenide.

The great advantage of solar panels is that they can be recycled, extracting mainly aluminum, glass and some minerals like silicon, copper, and polymers. This translates into less burning and more materials that can be used for other purposes and mainly to the manufacturing of new or refurbished solar panels.

Some regulations in the EU market known as the EU Waste Electrical and Electronic Equipment (WEEE), already require that manufacturers of solar panels finance the costs associated with collecting and recycling of expired modules. Initiatives like these could lead to the production of 60 million new solar panels by 2030 according to IRENA report.

No Gas Emissions

The best advantage of solar energy production for the environment is that there are absolutely no gas emissions attributed during the production of electricity. Meaning no carbon dioxide, sulfur dioxide or nitrogen oxide needed to generate electricity that would be harmful for the human’s health.

More Solar Energy Means Less Fossil Fuels

While we make the transition to an almost complete renewable energy market, we must guarantee supplies of electricity different from fossil fuels. While you purchase solar energy it means that you are not generating GHG emissions to produce the electricity that you need, but it also means offsetting electricity production from other fossil power plants, reducing the GHG from both perspectives.

The Use of Portable Solar Panels and Solar Generators

Portable solar panels can also contribute to the fight against climate change since every little drop of electricity that is not taken out of fossil fuels is good for the environment.

a portable solar panel charging a mobile phone

Moreover, portable solar panels have very important uses in rural regions where access to electricity is limited. Regions like Kenya make use of portable solar lanterns that can provide over 10 hours of light using a rechargeable battery powered by the sun. This avoids the use of other older sources of light like kerosene lamps or candles in regions where there is no access to electricity, avoiding the risks of fire that can be harmful to the environment and for the communities.

Such solar panels can be connected to solar generators which allow the storage of power from the sun. The portable solar generators can then be used when needed and can also easily transported for use on the go.

RV Solar Panel Kits and Solar Panels for Camping

RV solar kits are commonly available nowadays because they are a reliable source of electricity when you go camping. Instead of depending on plugging in a campground site which electrical systems may not receive proper maintenance, it’s better to purchase solar panels for camping. This will allow you to feel relaxed because your batteries will be charging with solar energy every day without using electricity from fossil fuel sources.

The Use of Solar Chargers and Solar Power Banks

Finally, portable solar chargers installed with solar power banks are also a nice combination to provide an off-grid solution for those people that go camping or that travel a lot around the country.

Solar power banks have also demonstrated to be more useful, safe and reliable under scenarios where the regular power grid is not available. For instance, the people from Portable Electric have designed a renewable power source solution for the off-grid sector called VOLTstack. This generator, powered by solar panels, produces no contamination as a diesel generator would in environments such as forests, beaches, and deserts where carbon dioxide should not be emitted.

Actually, under disaster conditions like hurricanes or floods, VOLTstack has the advantage of sustainably powering communities that have been affected by these natural disasters in moments when transporting fuel for diesel generators would be very costly and difficult.

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house with solar roof shingles featured image

Deciding Between Solar Roof Shingles or Solar Panels

Deciding Between Solar Roof Shingles or Solar Panels


Written by qualified solar engineer Leonardo. Last updated:

Installing solar panels is a proven way to generate your own electricity and save on power bills. However, solar roof shingles can be a viable option for new homes (or if you are planning a roof replacement). Unlike conventional panels, which are installed with racking on top of your roof, solar shingles have built-in solar cells.

On average, solar shingles are twice as expensive as panels. In the US, a solar panel system costs around $3 per watt of installed capacity, while the cost of solar roof shingles is between $5 and $7 per watt. However, consider that solar shingles also accomplish the function of a roof. While shingles are more expensive than panels by themselves, they save the cost of the roof beneath.

Consider that roof tiles have a lower efficiency than normal panels, which means you need a larger area for a given system capacity. To ensure you are getting the best deal, getting quotes from several solar roof shingle installers is recommended.

The Cost of Solar Roof Shingles

Close up of a Tesla solarglass roof

Just like with solar panel systems, the cost of solar power roof shingles varies depending on the brand and installer. For example, the cost of a Tesla solar roof is normally above $6 per watt, but there are manufacturers that offer solar tiles for less than $5 per watt. Solar roof costs are also affected by the project’s location. Since the technology is less widespread than normal panels, costs increase if there are no providers nearby.

Considering that the price of solar panel installation is around $3 per watt, you can expect to pay around $30,000 for a 10-kilowatt solar system. If you want to reach the same capacity with solar panel roof shingles, you can expect to pay between $50,000 and $65,000. Based on roof area, the installed cost of solar tiles ranges from $20 to $25 per square foot.

  • Since solar tiles have twice the cost of panels for a given capacity, their payback period is also twice as long. However, solar shingles can be financially viable if you were going to pay for a new roof installation anyway.
  • When choosing between solar shingles and panels, the appearance of each option also matters. If you prefer the look of solar shingles and are willing to assume the extra cost, they become an option even if you don’t plan a roof replacement.

In October 2019, Tesla revealed a redesigned version of its solar tile system called the solar glass roof. According to the company website, the estimated cost of a 10-kilowatt system is $33,950. While the price can increase depending on roof conditions and project location, this is much closer to the cost of traditional solar panels.

Do Solar Roofs Get the Federal Tax Credit Incentive?

The federal tax credit for solar panel systems is also available for solar shingle installations, making them less expensive to purchase. However, the benefit only applies for roof sections that use solar shingles. For example, if you plan to replace a 3,000-square-foot roof with 2,000 sq. ft. of solar shingles, the remaining 1,000 sq. ft. are not covered by the federal tax credit.

As of 2019, you can deduct 30% of your solar energy investment from federal taxes. However, this will decrease to 26% in 2020 and 22% in 2021. Only a 10% tax credit will remain from 2022 onwards, and it will only be available for solar energy systems in commercial buildings.

How Much Energy Do Solar Roofs Produce?

If you compare one solar tile with one solar panel, the electricity output of the panel is much higher. Solar tiles normally have a capacity below 60 watts, while many panels now have a power rating above 300 watts. To reach a certain capacity in kilowatts, the required amount of solar panels will be less compared to solar shingles.

For both solar panels and roof shingles, how much energy is produced depends on external factors as well.

  • Some locations are sunnier than others. Regardless of the type of solar energy system, the electricity production increases along with sunshine. For example, California is much sunnier than New York. If you use solar shingles of the same capacity in both states, the electricity output per shingle will be higher in California.
  • The orientation of solar tiles and panels is also important. In the northern hemisphere, south-facing roofs get more sunlight than north-facing roofs. If you only plan to use solar tiles in some areas, find out which sections of your roof get the most sunshine.
  • Shadows reduce the productivity of all solar energy systems, regardless of their type. When defining the layout of your solar installation, shaded areas should be avoided.

A solar shingle can be described as a smaller solar panel embedded into a roof tile. The design principles used to maximize the productivity of the panels apply for shingles as well.

When Are Solar Panels Recommended Instead of Solar Roofs?

A home with solar panels installed on the roof

If you have no plans to build a new home or to change your roof and you are not willing to pay the extra cost of solar shingles, you can still save money by using solar panels. For example, if you recently bought a new home with a normal roof, using solar shingles is like paying for your roof twice.

Compared with solar roof installations, the time it takes to install solar panels is shorter. Solar shingles involve a partial or complete roof replacement, which can take several days, or even weeks in a large property. On the other hand, panel installations are often completed in one day. With a quicker installation, you can start saving on power bills earlier.

Before proceeding with a solar installation, take your time to contact several providers, and get familiarized with the different types of solar panels available. For example, if you have limited roof area, a solar panel model will a high efficiency will maximize the electricity output.

Solar Panels and Solar Roof Shingles: Final Comparison

The following table provides a summarized comparison between solar shingles and conventional panels. Similar to many other home upgrades, each option has advantages and disadvantages.


Solar Panels

Solar Shingles

Typical cost of a 10-kW system


$50,000 – $65,000

Wattage per unit

Over 300 watts per panel

Below 60 watts per shingle

Installation method

Racking on top of your roof

Become part of your roof

Service life

Over 20 years

Over 20 years


Visible panels

Look similar to asphalt shingles

Recommended usage

Existing roof with no replacement plans

New constructions, roof replacements, homeowners who prefer the look of shingles and are willing to pay the extra cost

Solar roof tiles are a higher-cost alternative to solar panels, but they combine roof tiles and panels into a single element. In new constructions and roof replacements, solar tiles can help you save on materials and installation costs.

Solar shingles can be combined with battery systems just like normal panels, to store electricity for nighttime, rainy days, or blackouts. Battery systems can also be used to participate in load management programs where utility companies offer them. The federal tax credit incentive also covers batteries if they get at least 75% of their charge from a solar energy system – this applies for both solar panels and solar shingles.

The cost of solar tiles can be expected to decrease over time as solar panels became more affordable. The new solar glass roof by Tesla is a step in this direction, bringing the cost of shingles closer to that of conventional panels.


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old photograph of two men fixing a solar panel system to a roof

The History of Solar Panels

History of Solar Panels


Written by qualified solar engineer Aniket. Last updated:

The history of solar panels can be described by Becquerel’s discovery of photovoltaic effect, or the invention of first solar cell by Chapin, Fuller and Pearson in Bell Labs. But the story is much larger than just that. Since the beginning of life on Earth, the Sun has been the ultimate source of all energy. All the living creatures and the fossils trace their involuntary harnessing of energy back to the consistent and reliable showering of sunshine.

The remarkable portion, however, began when humans started harnessing this energy to convert into other forms and use it in a more versatile manner. We are at a point in time where we have started looking forward to a world powered almost entirely out of solar. It thus becomes interesting to understand the way solar panels work, and even look back upon its history.

Who Invented Solar Panels?

The solar technology has steadily evolved and continues evolving even today. Therefore, the credit for the invention of the modern solar panel cannot go to a single individual/entity.

It all started in 1839 with 19-year-old physicist named Edmond Becquerel. While working on the coating of platinum electrodes using silver chloride, he discovered a rise in voltage on exposure to light. This effect was named as photovoltaic effect. At that point, nobody would have predicted that it would become the basis for the predicted largest power generation method in the next 200 years.

Almost two decades later, another French inventor named Augustin Mouchot farsightedly realized that coal would eventually run out. Although his invention was a solar steam engine and not a solar panel, it was an important chapter in the history of solar devices. It even got Mouchot the title of ‘Lauréat de l’Institut’ by the Institut de France.

Two more decades passed, and in 1883, the first proper photovoltaic cell was devised by Charles Fritts, made from Selenium and having an efficiency of just 1%.

A few years later, Russian scientist Alexander Stoletov, regarded as the founder of electrical engineering, started studying the outer photoelectric effect discovered by Hertz. While expanding the research, he also built a solar cell on the same principle, and even discovered the sensitivity decrease (fatigue) of solar cells over time.

In the same year, Edward Weston filed a patent for current generating thermopiles using magnifying lens to concentrate sunlight. Within six years, Melvin Severy, the author, musician, engineer and inventor, also filed patents related to thermopiles.

The beginning of 20th century saw Albert Einstein publish a paper on photoelectric effect (1905AD). It even won him a Nobel Prize for the same, 16 years later,  while arousing some popular interest in solar panel information.

The mid twentieth century marks a very important era of developments in solar panels. In   American engineer Russell Ohl made the groundbreaking discovery of the P-N junction. P-N junctions are used in almost every complex electronic device today. He also invented the first modern cell operating using the P-N junction. Today’s PV cell is a lot similar to Ohl’s cell.

old photograph of american engineer Russell Ohl

(Russell Ohl, source – Solar Power Utah)

Daryl Chapin, Gerald Pearson, and Calvin Fuller of Bell Laboratories,   publicly demonstrated the first photovoltaic cell. It powered a toy Ferris wheel and a radio transmitter.

old photograph of Daryl Chapin, Gerald Pearson, and Calvin Fuller of Bell Laboratories

(The Bell Labs Team, source – Greentech Media)

When Were Solar Panels Invented?

As discussed before, crediting a single person or a single point in time with the invention of solar panels would be unfair.

To build a clear picture of the timeline of development of solar panels, we can divide it into three main parts. Here, we will look at the amount of development in the 19th, 20th and the ongoing 21st century.

The 19th Century

The 19th century saw scientists stumbling upon the ability of the sun’s light/heat to generate other kinds of energy. By the end of this century, physicists built simple devices that harnessed the sun’s energy to generate power, albeit with poor efficiencies.

This, however, paved the way for more advanced technologies that followed in the coming centuries. Some examples are Augustin Mouchot’s 1860’s solar engines, as mentioned previously.

old photograph of Augustin Mouchot’s solar engine

(Augustin Mouchot’s Solar Engine, Source – Academie De Touraine)

Diagram of Becquerel’s first solar system setup

(Becquerel’s setup, source – XENLife)

The first proper solar system with multiple cells by Fritts in 1884 marked the beginning of Solar ‘Systems’ or ‘Plants’.

Some basic devices did generate electricity, but by harnessing heat instead of light, unlike the modern cells. Yet, those were important advancements in the understanding of solar devices, such as the thermopiles of Weston and Severy (1888 and 1894 respectively).

Patent diagram of E. Weston and M. Severy’s soalr devicePatent diagram of E. Weston and M. Severy’s soalr device

(Patent diagrams of E. Weston and M. Severy’s devices, source – Smithsonian Magazine)

The 20th Century

Einstein’s paper and Robert Millikan’s experimental proof of photoelectric effect provided a base for inventions. Along with Bell Labs’ demonstration in 1954, Western Electric began selling commercial licenses for solar PV technologies.

Between 1957 and 1960, Hoffman Electronics achieved 8 to 10% record efficiencies. In 1963, Sharp corporation built the first solar module. Towards the end of this century, several pilot projects worldwide had been installed.

The 21st Century

By the end of the last century, considerable development had already been done in the solar field. However, major development was witnessed in the efficiency and cost areas. At the same time, had have dropped to less than a tenth, thanks to automated and bulk manufacturing processes.

When Was Solar Energy First Used?

The intentional use of solar power by using basic reflecting or refracting surfaces has been done for millennia. But devices that converted this energy into more usable forms ushered an era of new technological possibilities.

Speaking strictly in terms of solar photovoltaic panels, the first ever systematic use of solar energy was done by Charles Fritts. He installed the world’s first solar rooftop system in New York, in 1884, way before solar started becoming a common word. The panels were made from selenium and showed an efficiency of only 1%, whereas the components used to make a solar panel today come in a wide variety and exhibit amazing efficiencies going easily beyond 20%.

Old solar system installed by Charles Fritts

(Solar system installed by Charles Fritts, Source – Smithsonian Magazine)

The first space application of solar panels came in 1958, when the Vanguard I satellite was launched. Although it had only a 1-watt cell used to power its radio, this was the beginning. Further satellites such as Vanguard II, Sputnik 3, and Explorer III also used solar panels.

Diagram of the first space application of solar panels called Vanguard I

(Vanguard 1, source – Radio Museum)

In 1973, ‘Solar One’, the world’s first solar powered residence was built by the University of Delaware. In 1981, the first solar powered aircraft named The Solar Challenger was built by Paul MacCready.

image of solar one solar panels on a home

(’Solar One’, source – University of Delaware)

1982 witnessed the first megawatt scale commercial power plant in California, despite of high installation costs. Following this, more commercial solar plants started appearing on the map, such as the one in Pellworm, Germany in 1983. Since then, the graph has never ceased to climb, leading to a cumulative installed capacity of over 500GW by 2018, as solar panel installation companies had higher installation experience than nations did in the past.

Development of Solar Panels Over Time

Even if we consider a timeline from Bell Labs’ working cell to the current day, solar panels have come a long way. Everything from the size per unit capacity to the color of solar panels has undergone a change. Efficiencies have multiplied by 10 to 15 times and cost has dropped by a tenth or more. Every few years, researchers discover newer materials that are cheaper or more efficient. In the past years, Gallium Arsenide, Cadmium Telluride, Perovskite, Copper Indium Gallium Selenide, etc. materials have come up as interesting and promising alternatives to conventional solar cells. Even the way solar panels are made today has improved hugely, with automatic machines with remarkable productivity.

On the application side, we have started on the path of portable solar products, building integrated PV, and solar panel roads. Some people also believe in space-based solar that can transmit energy wirelessly without being affected by day-night cycles and temperature factors. Floating solar plants promise higher efficiencies thanks to better cooling and saving land area while reducing water bodies’ evaporation. Smaller applications like home solar products and solar lights have broken the image of solar being costly and a large-scale affair.

 All the graphs of dropping costs or growing adoption are exponential in nature. In one line, the story of solar has been exciting, and it will be a growing industry with new developments to look out for.


  1. The History of Solar – U.S Departament of Energy
  2. Solar Power – ScienceDaily
  3. Solar Cells for Space Applications – CESI
  4. Institute of Energy Conversion – IEC

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two different solar panels installed on a roof

The Different Types of Solar Panels

What Are the Different Types of Solar Panels?


Written by qualified solar engineer Leonardo. Last updated:

Most solar panels used in homes and businesses can be classified into three types: polycrystalline, monocrystalline, or thin film. There are many ways to manufacture solar panels, and this determines their final appearance.

The different types of solar panels are easily identified based on their appearance, and each type has advantages and disadvantages. Silicon is the most common material used for solar panels, and it is used for both monocrystalline and polycrystalline cells. There are more materials available to produce thin film solar panels, but many are manufactured from silicon as well.

In terms of physical appearance, the main difference between monocrystalline and polycrystalline solar panels is the color and shape of the solar cell. While monocrystalline panels have black cells with rounded or notched corners, the polycrystalline ones have blue cells with square corners.

a monocrystalline solar panel and polycrystalline solar panel side by side

Monocrystalline Solar Panels

Mono stands for single, which indicates that monocrystalline solar cells are produced from a single crystal of silicon. During their manufacturing process, silicon crystals are grown into large ingots which are then cut into individual solar cells. These cells are then assembled into solar panels.

Thanks to their uniform crystal structure, monocrystalline solar panels have the highest efficiency among the types commercially available, which is above 20%. Monocrystalline panels are also characterized by their color, which is black or a very deep blue.

Compared with other solar panel types, monocrystalline panels are the most efficient option but also the most expensive. They are normally recommended when there is little space available, since their high efficiency maximizes the amount of electricity obtained. Monocrystalline panels were the first type to be invented, and as a result they are the most developed.

Polycrystalline Solar Panels

Also known as multicrystalline solar panels, these are the most common type. As their name suggests, polycrystalline cells consist of several small crystals of silicon in an irregular arrangement. The crystal fragments produce when monocrystalline cells are cut can be recycled to produce polycrystalline cells.

These panels are manufactured by melting multiple silicon fragments and pouring them into a mold, instead of using a single crystal. This process has a lower cost, but it results in a slightly lower efficiency of 15% to 20%. As a result, a larger area must be covered with polycrystalline panels to convert a given amount of sunlight into electricity. However, thanks to their lower price per watt of capacity, polycrystalline panels command the largest market share.

Polycrystalline panels can be considered the intermediate option in terms of cost and efficiency. They are less expensive than monocrystalline panels, while offering a higher efficiency than the thin film. These panels are recommended for most projects, since they offer decent efficiency for a reasonable cost.

Thin Film Solar Panels

As their name implies, this type of solar panels does not use silicon cells. Instead, the semiconductor material is simply applied as a thin layer on a substrate. This manufacturing process is very cheap, but it results in a much lower efficiency compared with monocrystalline and polycrystalline panels. This doesn’t mean they aren’t useful.

Most thin film panels only have an efficiency slightly above 10%. The most efficient models reach an efficiency close to 15%, which is comparable to the lower end of efficiency for polycrystalline panels. Unlike the other solar panel types, these can be manufactured from materials other than silicon, including cadmium telluride (CdTe) and copper indium gallium selenide (CIGS).

Many portable solar panels are of the thin film type to achieve a lower weight. The thin film manufacturing method can also be used to produce flexible solar panels or roll up solar panels. Thin film panels are also common in mobile applications where low weight is an advantage, such as RV solar kits.

How to Categorize the Different Types of Solar Panels

Once you know the appearance of each type of solar panel, telling them apart is very simple. You must simply observe the physical features and color of the panel:

  • If the solar panels have a uniform surface that is not divided into individual cells, they are thin film panels, regardless of the color.
  • If the solar panels have blue cells with straight edges, they are polycrystalline. As mentioned above, this is the most common type.
  • If the panels have black or dark blue cells with rounded edges or an octagonal shape, they are monocrystalline.

In spite of their differences, the three solar panel types are based on the same physical principle. When sunlight reaches their surface, photons (light particles) cause the movement of electrons, producing an electric current. In fact, this happens when solar panels are exposed to any source of light, but sunlight happens to be abundant and free.

Monocrystalline and polycrystalline panels can also be described by the number of solar cells they have. 60-cell and 72-cell panels are the most common, and 96-cell panels are also available. Some solar panels have their cells cut in half with laser, which provides a slight improvement in service life and efficiency.

The following table summarizes the advantages and disadvantages of the three main types of solar panels. The best choice depends on the application, and neither of the types can be considered better than the rest:

Solar Panel Type




Good efficiency. Intermediate price.

Less efficient than monocrystalline panels.


Highest efficiency.

Highest price.

Thin film

Lowest price. Lightweight.

Lowest efficiency.

The appearance of solar panels is a subjective factor, but it can also influence the purchasing decision. Assuming a client has the budget and site conditions for any type, the solar panel choice may be based on how it looks. For example, while some building owners may prefer the uniform surface of thin film panels, others may prefer the conventional blue color of polycrystalline panels.

Another important factor that clients must consider is the life and quality of the solar panel type. Monocrystalline panels are more expensive because of their efficiency. Oftentimes, higher efficiency leads to a longer life and faster charging times. They also power almost four times the electricity of thin film solar panels, and they’re much more space-efficient. If a consumer was looking to buy panels for a fast-paced environment requiring consistently large amounts of electricity, the consideration of monocrystalline panels would be wise.

With that same logic, thin film panels are ideal if you’re looking at carbon offset. They’re also very good when you have a large space that needs covering (without the need for the highest-efficiency) because of their ability to easily cover massive spaces and rooftops.

Other Types and Styles of Solar Panels

The three solar panel types described above are the most common, but other options have been developed for specific applications. This section will describe other ways to harness sunlight.

Thermal Solar Panels

Thermal solar panels are different from the other types, since they are designed to heat water instead of producing electricity. Instead of having solar cells, these panels have tubes that are designed to circulate a combination of water and antifreeze. The tubes are painted black or covered with a dark surface to maximize the amount of sunlight absorbed.

Bifacial Solar Panels

Bifacial solar panels are characterized by their ability to gather sunlight from both sides, by exposing both the front and the backside of solar cells. This increases electricity generation: all the sunlight reflected from the surface below the panels reaches the solar cells as well. Bifacial panels can be monocrystalline or polycrystalline, and they are available in framed and frameless versions.

Transparent Solar Panels

Transparent solar panels are still an emerging concept. Since they are transparent, a large portion of the sunlight received is allowed through. While this reduces efficiency, it also increases the possible applications of transparent solar panels. They can be used as windows in homes or vehicles, and as covers for the screens of mobile devices, among other applications. The more panels used, the higher the efficiency will be.


Heliostats are not solar panels strictly speaking, but they are used for large-scale power generation with sunlight. Heliostats are mirrors that track the sun, reflecting light and focusing it on a specific target. Arrays of heliostats can be used to gather sunlight from a large area, focusing it to create an intense heating effect. The concentrated heat is enough to drive a steam turbine and generator. This concept is called concentrating solar power, or CSP.

Concentrator Photovoltaics (CPV)

Concentrator Photovoltaics is an emerging technology that uses lenses or mirrors to focus sunlight into a highly efficient solar panel. CPV technology achieves a higher efficiency than even monocrystalline panels, but the potential applications are limited by a high cost. CPV systems are often combined with solar trackers and cooling systems to increase efficiency further, but this also makes maintenance more complex – adding to the overall cost. Maintenance costs add up, and this is an important factor to consider when purchasing.


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large solar farm in california

How Many Solar Panels Needed to Power the U.S.?

How Many Solar Panels Would be Needed to Power the U.S.?


Written by qualified solar engineer Aniket. Last updated:

About 7.86 billion solar panels would be needed to power the U.S. on solar energy. This is derived from the fact that every year the U. S. consumes around 4000 billion kWh of electricity. This means an astounding consumption of 12,000 kWh per year per capita.

If each one of the 7.5 billion humans on the planet start consuming this amount of energy, all of the oil in the world would last only nine years. In addition to this, climate change data repeatedly points to a probable 2°C rise in average temperatures in this century, bringing catastrophes like never before. These are reasons enough to wonder how the entire U.S. can become solar powered. Let’s find out how.

The Total Installed Capacity Required

If we were to think of the solar panels needed to power the entire world, a significantly large portion of that would be needed for the U.S. alone. Currently, the existing infrastructure in the nation churns out over 4000 billion kWh every year. That means a daily average of almost 11 billion kWh.

Dividing the above number by the number of hours of energy consumption would give us hourly energy data, or simply the power consumption (kilowatt-hours ÷ hours = kilowatts). Now, unlike conventional power generation sources, solar cannot operate 24 hours a day. This is why the hourly consumption and hourly generation numbers for solar power cannot be the same.

For example, if one needs 24 kWh per day, his hourly average consumption would be 1 kW, but a 1 kW solar plant would not generate energy for 24 hours. This is due to the day-night cycles. Owing to this, the number of hours of peak sunshine at any location matters.

In our case, the full sunshine hours in the U.S. vary from 3.5 to 5.5. For our calculation, we will assume a national average or 4. This can, of course, be different based on the latitudes where the majority of the solar plants are located. Going back to our calculation, 4000 billion kWh with a 4-hour full generation every day gives us 11 billion kWh ÷ 4 hours = 2,750 million kilowatts, or better said 2.5 TW.

Annual PV Solar Radiation in the United States

Annual PV Solar Radiation in the United States (Source – NREL)

The current standard size of panels used in a large sized solar plant is easily over 350W. Assuming this power rating, we would need to divide 2.75 TW by 350W, which gives us the gigantic number of 7.85 billion (7,857,142,857, to be precise) panels required. This number does look intimidating, but with a large number of solar companies in U.S., it can be turned into reality.

Area and Costs Required

It is nearly impossible to install all these panels at a single location for more than one reason. We can, however, hope for a cumulative installed capacity crossing the required number (with plants spread throughout various states). A megawatt of solar power plant requires about 5 acres of land. 2.75 TW, or 2,750,000 MW would require 13,750,000 acres.

An important point to note here is that not all the panels have to be installed on vast areas of land. Rooftop solar plants have rapidly gained traction. The number of solar panels required to power the average house, in almost all cases, would find sufficient roof space on homes in the U.S.

For many decades, high cost remained a serious obstacle in the widespread adoption of solar. In the past few years, costs of solar panels have experienced a nosedive. The installation costs don’t burn a hole in your wallet, thanks to a well-established industry with considerable competition. Focusing on large scale deployment of solar, costs can be controlled even more by purchasing panels made in the U.S.

In the end, we cannot afford to ignore the climate story. We need to make sincere efforts towards remarkably large deployment of solar power, starting today.

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the two solar panels placed on top of the world.

How Many Solar Panels Needed to Power the World?

How Many Solar Panels Would Be Needed to Power the World?


Written by qualified solar engineer Aniket. Last updated:

A total of 51.42 billion solar panels would be needed to power the entire world on solar energy. Here we are supposing a panel size of 350W for the calculated size of 18TW of solar plants. How do we arrive at this number? We receive a staggering 1.74*1017 watts of energy from it. To put this into perspective, this is about 10,000 times more than what humans need.  In 2018, the world consumed about 23,000 tera-watt-hours of energy, in that single year, which translates to an average consumption of 63 TWh daily. Taking that into account, we would need an approximate total of 18 TW of solar.

The sun has always been the source of all energy on Earth. Plant-based, fossil-based, wind or water, all energy is a consequence of the energy delivered by the sun.

Multiple workers installing a solar panel farm in a field

FPL Miami-Dade Solar Energy Center Tour in Miami (Source – SFBWmag)

How We Reached This Number

1 kWh of energy can light a 10W lamp for 100 hours, or a 1000W water heater for one hour (W*h =Wh, kW*h = kWh). Add nine zeros in front of a kWh, and you get a TWh. Considering the average total sunshine hours (including shading, orientation, dust and other losses) to be around 3.5, the average amount of energy produced by 1 TW of solar plants will be 1TW*3.5h = 3.5 TWh per day.

Thus, to generate 63 TWh per day, we would need 63/3.5 = 18 TW of solar power plants. Selecting one of the largest sizes of panels, i.e. 350W, we would require the above-mentioned number of 51.4 billion panels (18000000000000W/350W = 51.42 billion panels).

A single large solar plant with over 50 billion panels is a fantastic thing to imagine. However, we have to keep in mind that constructing a single such plant would be impossible, from the economical, logistical and technological aspects. Despite this, it would be a realistic aim to cover various suitable locations all over the world with a collective 50+ billion panels.

It would be also interesting to understand the amount of solar panels needed to power the U.S. and other nations with high per capita consumption. Adding up those numbers can help get a clear and realistic picture.

How Much Space Would Be Required?

Solar panels, at least the modern ones, operate with an efficiency or around 20%. This means that out of the total energy that light brings with it, only a fifth is converted into electricity, that too in ideal conditions. What this means for us is that space is an important investment as far as solar power is concerned.

Speaking of residential plans, the amount of solar panels needed to power an average home can be anywhere between 7 and 100, depending on how large the house and its consumption is.

In case of large systems, as a rule of thumb, a typical solar system of 1MW capacity requires an area of 5 acres, or over 200,000 square feet. Thus, for a terawatt, after doing some math, it will require about 7,800 square miles.

Solar panel farm in the Negev desert

This is about the size of a country like Israel or Slovenia, and larger than the area of some other countries. But as discussed before, it is highly unlikely that we can succeed building this gigantic single solar plant in one place. But a cumulative area of 7,800 square miles throughout the world is what we can practically aim at.

The Costs Involved

As much as the amount in the power generation per panel varies with location, the cost also varies from state to state and country to country. These variations can be attributed to differences in costs of manpower, transportation and even materials.

The cost of installing solar panels for a megawatt capacity is around a million USD. Whereas, in countries like India and Brazil the costs are significantly lower, somewhere between 0.6 and 0.8 million USD. Assuming the 1 million/MW cost, the global63TW plant would require 63 quadrillion (63*1015) US dollars to be built.

That is equivalent to a lot of countries’ GDP combined together, and this precisely is the reason we need all countries to believe together in a solar powered future.

While dealing with costs, we do have to keep in mind that although free, a solar system does not last for an indefinite period. Looking at the average lifespan of a solar panel, it is clear that we will need renewed investments every few decades.

Nevertheless, in the longer term it is still cheaper than fossil energy and even better for the planet. Nearly every climate change report has stressed on the immediate need of solar power acceleration.

Key Takeaways

It would not be wrong to say that with today’s technology costs and abundance of sunlight, solar power may soon become mainstream. A world powered entirely from solar is not as impossible as it sounds. The costs required for the same may sound huge but are actually profitable and ecologically more sensible in the longer term.


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man holding a recycling logo in front of solar panels

Can Solar Panels be Recycled?

Can Solar Panels Be Recycled?


Written by qualified solar engineer Carlos. Last updated:

Yes, solar panels can be recycled into raw materials such as aluminum, polymers, or plastic and glass. But how much of these materials can be obtained and what is the recycling process like? We will address these questions and more in this short article about solar panel recycling.

Solar panels – A Big Industry That Must Take Care About Recycling

The solar industry growth rates keep increasing every year across the world almost exponentially. However, an industry that is proud to promote clean energy consumption and that is proud to be a sector concerned about climate change, cannot forget to dispose properly of the electronic products that exceed their lifespan.

Countries like the US, Japan, and Germany have reached almost 50 GW of solar PV capacity to the end of 2017, which as we can imagine, represents millions of solar panels that will become waste between 2040 and 2050.

Solar panels do in fact last between 25 and 30 years. That being said, the day will eventually come when those solar panels will stop working or degrade to a level of inefficacy. At that moment, the lifespan will have ended and they will have to be recycled into raw materials for further manufacturing of new solar products.

As you can imagine, the short answer to the question above is yes, solar panels can be recycled. But what can be obtained from this recycling process?

What Materials Can Be Obtained from Solar Panels?

Solar panels have to be classified according to the technology in order to be recycled.

Conventional silicon-based technologies like monocrystalline or polycrystalline modules can be treated similarly, but thin-film solar panels based on components like Cadmium Telluride (CdTe) or Copper Indium Gallium Selenide (CIGS) must be treated separately, as their composition is much more complex and can even be toxic.

Conventional silicon modules are composed of materials such as copper (1% -interconnections), silicon (5% – solar cells), aluminium (8% – frames), polymers or plastic (10% – encapsulant l) and glass (76% – surface of module).

a breakdown of the different materials that make up conventional silicon modules

(Source – IRENA Report – End of Life Management)

On the other hand, thin-film technology contains several thin layers of semiconducting materials that are deposited onto glass, polymers, or metal.

CIGS solar panels can be adjusted to achieve high light absorption, thanks to the adjustment of the light spectrum that varies according to the composition of the semiconducting materials (indium, gallium, and selenium). From CIGS modules we can recycle 89% of glass, 7% aluminum, and 4% of polymers. The extraction from other materials such as copper, indium, gallium, selenium, zinc, and other metals is almost negligible (0.2%).

CdTe solar panels use cadmium sulfide and other materials such as cadmium, tellurium, and copper to develop the layers of solar cells. The proportion of glass in CdTe modules is higher than in other modules reaching 97%, and leaving nearly 3% for polymers. Other materials such as nickel, zinc, and other metals represent less than 0.5% of the total volume of the module.

Here we can see a proportion of each technology and its materials in a percentage of the total volume of the module.

bar chart to show the evolution of materials used for different pv panel technologies

(Source – IRENA Report – End of Life Management)

What Happens in the Recycling Process?

The first step is disassembly and dismantling of the PV array, including cables, steel, aluminum, racking and other electronics (inverters, batteries, etc.). Then, solar panels are packed and transported to recyclers or landfill sites depending on local regulations.

Since most PV systems were installed from 2010 onwards, PV waste quantities are still not as large as to create massive market incentives for investors to install specialized PV recycling plants. Thus, solar panels are typically processed in general recycling plants.

Major components such as glass, aluminum, wiring, and polymers can be easily recycled by merely mechanical separation. Then, to ensure that these materials do not contain high impurity levels that could reduce the resale prices of these materials when getting back to the market, it is necessary to conduct a combination of thermal, chemical, and metallurgical processes.

Regarding the process for the laminated glass component of silicon modules, we can see the steps in the figure below.

process of how to recycle laminated glass

IRENA Report – End of Life Management

Aluminum, steel frames, and copper from wires can be included in metal recycling loops, while polymers can be processed in waste-to-energy plants.  On the other hand, recovering rare (silicon, silver, copper) or hazardous materials (cadmium, lead, selenium) requires advanced processes. Through pyrolysis (decomposition at high temperatures of 500°C) it is possible to remove the solar cell metallization and dopant layers to cast a new silicon ingot from the silicon material obtained. More detailed steps can be found in the figures below

explanation of advanced recycling of materials using pyrolysis process

(Source – IRENA Report – End of Life Management)

explanation of thin-film recycling process

(Source – IRENA Report – End of Life Management)

Large-Scale Solar Panel Recycling – Can It Be Done?

We have seen that solar panels can be recycled. However, a more important question might be:

Does the solar industry have the resources, tools, recycling plants, and market to recycle large quantities of solar panels?

The short answer for that is no.

The market for this sector is not yet clear nor is its policy framework, regulations, economics or methodologies in many parts of the world.

This presents a new environmental challenge for the PV industry that needs to be addressed in the US, Japan, Germany, India, and especially in China as the country with the highest accumulated PV capacity in the world (130GW in 2017).

Actually, based in IRENA’s estimations on a report from 2016, global panel waste projections will be as high as 78 million tonnes, equivalent to almost 4,500 GW in capacity by 2050. The greatest contributors to this waste will be China, the US, Japan, India, and Germany as you can see below.

bar chart to show the cumulative waste volumes of top five countries for of end-of-life pv panels in 2050

(Source – IRENA Report – End of Life Management)

What Can Be Done to Promote Solar Panel Recycling?

The first step is developing a policy framework just as it exists in Europe with the Waste Electrical and Electronic Equipment (WEEE) regulation that requires all producers supplying solar panels to the EU market to finance the costs associated with dismantling, transport, and recycling of end-of-life modules.

Companies like PV Cycle in the EU have also intervened in this aspect as a non-profit organization that focuses on the recycling of solar panels inside the EU. PV Cycle leads the way in the definition of methodologies and costs to effectively recycle the solar panels. Other companies like Veolia and Recycle PV also do their part in the US to start the development of the recycling market.

As more companies join to this market, it is also necessary that more government initiatives take place, such as the stewardship of Washington, which requires manufacturers who sell solar units in the state of Washington to be responsible for financing and providing a recycling program for their modules.

The European continent has led the way on this sector, but it is a matter of time until other regions like China, Japan, US, India, and Australia follow the path to ensure the conservation and reuse of the PV market.

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Solar panel in the style of the us flag

Which Solar Panels Are Made in the USA?

Which Solar Panels Are Made in the USA?


Written by qualified solar engineer Carlos. Last updated:

So Many Solar Panels – How Do You Choose?

There are many brands on the market, but only some of them are made in America. Heliene, Mission Solar, Silfab, Serpahim USA, SolarTech Universal and Suniva are among the most popular. Many Americans choose to install a US-made solar panel brand. The way solar panels are manufactured, they are built to be durable and resist damage over time so your solar panels should last at least 25 years, therefore quality is an important parameter to base your decision on.

Selecting a solar panel model is not an easy task because there are dozens of solar panel manufacturers available in the market. Therefore, to make the best decision, we must apply filters to make our choice wiser.

Some homeowners or designers may be familiar with a particular brand and only select solar panels from that manufacturer. Others may select solar panels according to their efficiency values. However, some American homeowners or designers may opt to select solar panels according to their country of manufacture.

Besides, the following recent event can increase the interest in American made solar panels.

Solar Industry and the Trump Administration

In January 2018, President Donald Trump announced a 30% tariff for foreign solar panels imported into the USA. The announcement came into effect in February and will drop 5% each year down to 15% in 2022, time from which it will remain at 15%.

Whether you agree with this decision or not, the truth is that in the next few years solar panels made in foreign lands will have to increase their value in order to compensate for the tariff imposed by Trump administration.

This will present an opportunity for American manufacturers to step up in the line since they will be more competitive than ever. 

To give you an idea of the top American brands that manufacture their solar panels in the USA, we have prepared this list for you with some of their best solar panel options.

Solar Panel Manufacturers in the US


Maybe one of the most remarkable American manufacturers of solar panels with manufacturing facilities in Minnesota, Heliene solar panels are eligible for the Minnesota Solar Incentive Program. They are dedicated to homeowners that install solar panels made in Minnesota.

Their most amazing solar panel is the monocrystalline 96 cell model with a  power output of 490 Wp (unique in the solar industry) and a maximum efficiency value that rises up to 19.1%. Truly a premier solar panel made with American muscle.

Mission Solar

Mission Solar is based in San Antonio, Texas. Their solar panels comply with IEC and UL standards related to withstanding environments with harsh snow, wind, and salty conditions. Their production process guarantees high-quality solar panels that must pass through several technical revisions.

Maybe their most remarkable solar panel is the 72-cell monocrystalline PERC cell model, with a power output of up to 365 Wp and efficiency close to 18.46 %.

Silfab Solar

Silfab Solar is a company with 35 years of experience in the manufacturing of solar panels. The company operates in Bellingham, Washington with 158,000 sq.ft dedicated for facilities of automated production lines that design PV modules specifically for the American market.

The company has recently announced their new set of astonishing solar panels that will be available in 2019.

First, we have the 60-cell SLA-MWT 320Wp Monocrystalline solar panel with 20% module efficiency, 30-year linear power performance guarantee, and a beautiful dark black design!

There is also the 120-cell monocrystalline SLA-M-HC-320 module that integrates half cell technology, PID resistance for high PV string voltages, and an efficiency of 20%!

The company also integrates bifacial PV modules into their repertoire. Models like the SLG-X Bifacial solar panel with 360Wp in the front side could achieve up to 450 Wp if combined with both front and rear sides for power production.

Besides, rear side power production can contribute up to 30% with an amazing 85% bifaciality factor, integrated with PID resistance,  and an incredible performance against LID losses (reductions from 3% annual losses to 0.3%!). Definitely a premier jewel of the solar panel industry.

Finally, in 2018 Silfab Solar expanded its operations in the US market by acquiring Itek Energy (another important US solar panel manufacturer).


Solaria is a company with over 18 years of experience that manufactures its products in California and South Korea. The company is among the top solar panel manufacturers with efficiency values that can reach up to 19.9% efficiency. The premier product of the brand is the Solaria Power XT 360.

Seraphim USA

100% American company headquartered in Houston, Texas with manufacturing facilities in Jackson, Mississippi. Seraphim offers monocrystalline and polycrystalline solutions to the PV market. Their products offer quality performance against salt mist and ammonia corrosion, PID durability tests, and top rank among Photon Lab’s yield measurement tests. Their top solar panel is the SRP-6MA model.

SolarTech Universal

The only solar panel manufacturer in the State of Florida. Established in 2012 with manufacturing facilities in Riviera Beach.

The company promotes their own original EPIQ technology that combines PERC cell, heterojunction cell, and smart wire (no busbars to collect electrons) technology into a single design that promises high energy performance. 

Their top product is the EPIC 325W HJT model based on heterojunction cells, smart wire technology, 19.9% efficiency, and 30 years of guaranteed performance.

Solar Tech innovation in the manufacturing process is something worthy of admiring and you can check it here.


Suniva is headquartered in Atlanta with manufacturing facilities in Georgia and Michigan. The company has earned the right to be among the Top 50 fastest growing solar companies in Atlanta along with other prizes such as Georgia Manufacturer of the Year and Renewable Energy Exporter of the Year.

Their product is based on Suniva’s ARTisun Star technology offering monocrystalline and polycrystalline options to the American market.

Does It Matter Where Solar Panels Come From?

We have examined some of the most remarkable solar panels made in the USA, however, you may find other brands such as SunSpark, Kyocera Solar, Centro Solar America, Mage Solar, and Zebra Energy, that also manufacture their solar panels inside the US.

Quality of US manufactured products is generally indisputable. However, that does not mean that you cannot find premier and high-quality modules that are manufactured outside the US.

For example, Sunpower has its headquarters inside the US but manufactures in China and the Philippines, and they have been the worldwide top brand for several years. Jinko Solar, LG, and Trina Solar are other examples of high quality standard solar panels that are not manufactured inside the US.

If you opt for US solar panels due to patriotic reasons then that’s perfect! But if not, do some research to find a balance between quality, design, and costs!

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