making it a perfect source for generating energy – particularly when compared to fossil fuels, which need to be mined, extracted and transported leaving behind a trail of pollution and environmental degradation. Indeed, the sun is considered the world’s single most abundant energy source, producing an outstanding 173,000 terawatts of solar energy every second. This amounts to more than 10,000 times of the world’s total combined energy use¹.
As a homeowner or a commercial business owner, switching to a renewable form of energy such as solar energy provides a clean, affordable, and sustainable way to generate electricity. Key to most people’s motivation is the financial benefits that solar power can provide such as lower utility bills and increased home value. At the same time, this is a win-win situation as switching to solar energy also creates substantial environmental benefits.
The environmental benefits of solar energy
First, in contrast to fossil fuels such as coal, natural gas and oil, solar energy reduces air pollution substantially. When burned to generate energy, fossil fuels emit greenhouse gases such as carbon dioxide and methane along with a number of other gases and particles that pollute the air. An analysis by the National Renewable Energy Laboratory (NREL) found that widespread adoption of solar energy would significantly reduce nitrous oxides, sulphur dioxide, and particulate matter emissions, all of which can cause health problems. This would not only greatly benefit the environment as a lot of these pollutants contribute to acid rain, but it would also bring about substantial health benefits, such as fewer cases of chronic bronchitis, respiratory and cardiovascular problems, and lost workdays related to health issues²,³.
It is estimated that installing 100 GW of solar capacity, 437 mortality cases would be reduced in addition to heart attacks and respiratory diseases ³.
Second, generating electricity with solar panels produces no greenhouse gasses. This is in direct contrast to traditionally produced electricity using fossil fuels. Electricity accounts for 37% of US CO2 emissions and it is higher compared to both emissions generated by transportation and emitted by industry processes². As the Energy Research Centre of the Netherlands indicates solar electricity contributes 96% to 98% less greenhouse gases than electricity generated from coal². Even at its current level, solar capacity in the US is expected to offset as much as 16.8 million metric tons of carbon dioxide a year¹; a very important step towards mitigating the human impact of climate change. Other research data estimates that by 2030, with an installed capacity of 100 GW of solar power, the US could avoid 100,995,293 CO2 emissions by replacing natural gas and coal with solar power²,³.
Third, solar reduces water pollution because in contrast to energy generated by fossil fuels, solar photovoltaic cells don’t need water to generate electricity. Given how scarce a resource water is and how many countries are battling with severe cases of drought every year, this is one of the most important environmental benefits of solar. For example, traditional biomass and geothermal power plants, such as natural gas and coal-fired facilities, require substantial amounts of water to facilitate their vital cooling requirements. Solar energy does not require any water which means that local water resources remain intact and there is no competition with agriculture, drinking systems, and other vital water needs³.
Fourth, solar energy requires overall less resources in terms of its production and use. In other words, it has a more positive lifecycle assessment. As is true for most human activities, solar power does impact the environment by using land, water, and hazardous materials. What is noteworthy is that these impacts are minimal, especially when compared to the environmental impact of fossil fuel energy.
More specifically, compared with coal electricity, solar electricity¹:
- uses 86% to 89% less water
- uses 80% less land
- is 95% lower in toxicity to humans
- causes 92% to 97% less acid rain
- and 97% to 98% less marine eutrophication, the cause of algal blooms
What is even more astounding is that using solar energy even on an individual or residential scale can make a real difference²,³.
With a typical 4 kW residential solar power system, you can expect to offset nearly 200,000 pounds of CO2 over 25 years – this is equal to planting about 2,316 trees.
Larger residential solar power systems can save even more, offsetting 178 tons of carbon dioxide over a period of 30 years – that is equal to conserving 6.7 Olympic-sized swimming pools of water, planting 10 football fields of trees, and not driving 390,300 miles.
The environmental impact of solar energy
Having said that, not all solar panels provide the same environmental benefits. Their environmental impact across their lifecycle depend on how they were produced as well as for how long the solar panels can be used for. For example, some studies have found that mainstream Chinese-made silicon solar panels have more than twice the carbon footprint than panels made in Europe, and take up to 30% longer to offset the energy used to make them – this is without taking into account the impact of transport costs⁴.
Solar energy has clear environmental benefits. But one aspect which definitely can be improved is the end of life management of solar panels and specifically their recycling⁵. Given that solar energy is a relatively recent technological development which is only now being deployed in significant numbers, there aren’t enough locations to recycle old solar panels, and there aren’t enough non-operational solar panels to make recycling them economically attractive. Recycling of solar panels needs to be supported as precious materials used in photovoltaic solar panels, such as silver, tellurium, or indium, should be re-used. This should not be considered an unsurmountable problem: recycling technologies can be developed and commercialised when there is significant demand. This was the case for instance with PET bottles which only became possible in the 1990s.