One question many people ask when talking about solar panels is: how much CO2 is avoided with a photovoltaic system? Do these modern systems really help the decarbonisation? We answer this question in the article below.

Benefits of solar panels

We have already addressed the myths about photovoltaic systems. Among the most popular ones at the moment, there are two that we would like to focus on in this article: solar panels cost too much, and photovoltaic systems do not produce CO2 but at the same time pollute due to their production and disposal methods. Let us clarify.

First point. Although the initial cost of solar panels is significant, it is recovered many times over during their long life, which exceeds 25 years. Let us imagine that we have a company roof of 300 square metres and we decide to install solar panels with a total output of 10 kilowatts (kW). Let us assume that the total cost, including panels and installation, is $25,000. With an estimated annual production of 15,000 kilowatt hours (kWh), we would save an annual value of approximately $1,800 on electricity. It would take approximately 13.9 years to fully recover the investment. However, after this period, the energy produced would be essentially free of charge, offering considerable savings on energy costs in the long term.

Besides the return on investment, solar energy has the potential to reduce carbon emissions significantly. Unlike fossil-fuel power plants, solar panels generate electricity without emissions for decades. For example, 1,000 solar panels can save 3.3 tonnes of CO2 each for 25 years. This equates to 3,327.40 tonnes of CO2 saved overall. Considering an average commercial electricity price of 18.36 cents per kWh, the 11,515,000 kWh generated by solar panels is worth EUR 2,114,154.

And what about the carbon footprint due to the production of solar panels?

Renewable energy options, such as solar panels, play a key role in the fight against climate change and carbon emissions. However, there is a debate on the real carbon emissions associated with the production of solar panels.

The creation of solar panels requires a considerable amount of energy to power the machinery involved, that is beyond doubt. The evaluation of the’carbon footprint actual production of solar panels, however, is a daunting task for several reasons. Firstly, the different types of solar panels, which require slightly different production methods.

Monocrystalline panels, recognisable by their dark colour and elegant design, are made by shaping blocks of silicon during the production process. In contrast, polycrystalline solar cells are produced by fusing silicon crystals, an energy-intensive process that requires a different approach. The production of silicon emits about 6.0 kg of CO2 equivalent for every kilogram of silicon metal produced, and considering that about 11 grams of silicon are used per cell, it can be estimated that a solar panel requires about 660 grams of silicon. However, in addition to silicon, other metals such as copper, silver, indium and tellurium are used in the composition of solar panels, with carbon emissions also associated with their extraction.

Then there is the origin of the solar panels to consider: there are disparities in emissions from country to country. For example, China, which contributes half of the world's solar panel production, emits about twice as much per panel as Western countries.

According to assessments by the Intergovernmental Panel on Climate Change (IPCC), residential solar panels emit approximately 41 grams of CO2 equivalent emissions for every kilowatt-hour of electricity generated. These emissions are mainly related to the life cycle of the panels.

So solar panels have no real environmental benefits?

What is the point of adopting new renewable energy technologies if they pollute? Many people ask this question and we at Heiwit want to answer it clearly.

Considering the carbon footprint, it is clear that solar PV has a much better long-term footprint than fossil energy sources such as coal, oil and natural gas. From the point of view of the production process, solar panels emit around 40 grams (up to 50) of CO2 per kWh produced in the first years of operation. By the third year of use, most panels become zero-emission.

Even over the life cycle, the greenhouse gas emissions associated with solar energy are significantly lower than other sources. While solar panels produce zero grams of CO2 per kWh during operation, fossil sources such as natural gas, oil and coal emit significant amounts of CO2 per kWh generated, making solar energy a significantly cleaner option.

Even taking into account the production phase of the panels, solar energy is in a very favourable position compared to other energy sources, confirming itself as a valuable choice for reducing pollution and promoting environmental sustainability.

Can the carbon footprint of solar panels be reduced?

The carbon footprint of solar panels, estimated by the IPCC at 41 grams of CO2 equivalent per kWh of electricity produced, is subject to change and improvement over time. There are several strategies to reduce this footprint and make it more sustainable in the long term.

• production processes account for about two-thirds of the total life-cycle emissions of solar energy. These processes include the extraction of raw materials and the construction of production facilities, but can be improved by adopting renewable energies to power them, thus making solar energy cleaner from its creation
• the operational emissions of solar panels, once installed and in operation, are relatively low and can be further reduced by increasing the efficiency of the panels and making the most of sunlight conditions. For example, by combining solar panels with agriculture (agri-voltaics) or by adopting innovative solutions such as floating solar panels on tanks (float-voltaics)
• The dismantling and disposal phase of solar panels represents a small part of the overall carbon footprint, but can be further reduced by recycling the materials used in their construction. This solar panel recycling sector is growing rapidly and offers great opportunities to reduce downstream and upstream emissions

And if you are interested in reducing your company's carbon footprint and contributing to the 2030 climate targets established by the European Commission, consider installing photovoltaic systems on your roof with Heiwit. This solution will not only help you reduce pollution, but also allow you to profit from energy production. Visit our website to learn more.