Carbon footprint of solar panels

There’s a common misunderstanding about the carbon footprint of solar panels. It’s not null as it might appear, but make no mistake: it’s still a clean source of energy, and you’re gonna find out why in this article.

Carbon footprint of solar panels

The solar panel carbon emission is something around 50g of carbon per which kWh generated. This is super low, and after the first 3 years, the technology carbon footprint becomes neutral!

But how is that possible? It’s not some magical process that allows solar panels to become carbon neutral.

Well, the answer is on the solar cells manufacturing process.

In the same way any manufactured product ever made, the technology to build solar panels circuits uses other sources of energy, and these sources are not carbon neutral, such as coal – very common in the United States.

Yet, this carbon footprint of 50g per kWh is nothing compared to the amount produced by traditional sources of power, such as coal, that according to the U.S Energy Information Administration, is around 800g per kWh.

The best is yet to come: depending on the manufacturing method, the carbon footprint of solar panels can be 20 times smaller than coal powered electricity.

Solar panel manufacturing carbon footprint

If the goal is to fight climate change, it’s crucial to discuss the solar panel manufacturing process. This power source represented only 2% of the world’s energy budget, but this number already increased in 66% at the end of 2021 – according to Energy World website.

Since the U.S. goal for 2030 is to have 50% of the produced energy relying on renewable sources, there’s some myths to break about solar energy.

Monocrystalline solar energy

Composed of small silicon crystals, also called polysilicon. This material is produced on misaligned silicon glass, lying between amorphous silicon, in which there is no long-range order, and monocrystalline silicon

Polycrystalline solar energy

A silicon type used in virtually all of today’s electronic equipment. It has a great capacity to receive radiation. Because of its purity, its energy efficiency is between 14% and 21%, higher than that of polycrystalline silicon.

Are solar panels environmentally friendly to manufacture?

The production of solar panels is still not as sustainable as it could be. As other energy sources are used in this manufacturing process, photovoltaic panels demand large amounts of water and even fossil fuels.

Hydrofluoric and sodium hydroxides are some examples of materials used in the solar energy market, two types of materials that require severe waste treatment because they are extremely toxic.

In addition, the main energy source for heating silicon is coal. So at this point this is a disadvantage of photovoltaic panels.

An important fact to keep in mind is that the production of CO2 during the use of solar panels is so low that in about 1.3 years this carbon footprint is offset and from that stage on, solar energy becomes carbon neutral.

Do solar panels reduce your carbon footprint?

Yes, they do. Energy has just the major impact in the United States carbon footprint. Power is responsible for 73% of all carbon emissions in this country.

Of course, a relevant percentage of this number comes from the industrial processes, to keep all factory machines working 24/7 – but American houses have a important role in this matter.

The carbon emissions of a solar panel usage is something about 20 times smaller than the traditional energy (coal powered, mainly), so if you’re able to change your energy source, you can drasticly reduce your carbon footprint along the years.

How much greenhouse gases are produced by solar panels?

Solar energy has practically no waste. This fact may surprise many readers, but it is easy to understand when we realize that this renewable energy source does not require combustion.

Combustion is nothing more than a process in which a fuel (such as coal, for example) and high temperatures are used to generate energy.

In the case of solar energy plates, the radiation coming from the sun every day is enough to “force” the electrons in each photovoltaic cell to move, thus generating an electric current.

Therefore, according to information from the National Renewable Energy Laboratory (NREL) the estimated emission from a solar panel is 40g of CO2 per kilowatt-hour.

Are solar panels recyclable?

Solar panels are recyclable, bringing yet another advantage in the fight against climate change. Before talking about the process, let’s take a look at what the component materials of a solar energy panel are:

• 76% glass
• 10% plastic
• 8% aluminum
• 5% silicon
• 1% metals.

For the recycling process, as with any other type of product, the photovoltaic plates are disassembled to give the correct destination for each material.

An astonishing 95% of the glass used in the construction of these plates can be reused.

The metal parts that support the structure of a solar panel can be recycled to make a new panel or any other structure.

The rest of this material is treated at high temperatures (around 500°C) for recycling.

The plastic evaporates in this process and is used as a heat source, and the silicon particles are removed with an acid and melted down. These particles can be reused for the construction of new solar energy panels.

With all this treatment, about 85% of the solar panel can be recycled.

It is important to remember that these panels have a life cycle of about 25 years, and can reach up to 40 years of use in some cases.

Therefore, besides being able to be remade and producing a small amount of waste, this renewable energy source has an extremely long durability.

CO2 emission per energy source

In this table below, you can understand the carbon footprint of every energy source. Remember that the last column is the most important one.

Solar energy produces only 0.50g of carbon (CO2) for kWh, while the most eco-friendly source in this table is natural gas, that has 970g for kWh.