Solar is a renowned clean energy source, but some claim it’s not eco-friendly. Let’s dispel the myths and discuss the environmental impact of solar energy.
Most people want to protect the planet, which means more of us want to use renewable sources of energy like solar power. With an average annual growth rate of 50%, solar energy is experiencing a major surge in popularity in green circles.1 Why? The answer is threefold:
- The price of solar panels has fallen over the past decade
- The solar industry’s sheer economic power
- Solar’s squeaky-clean reputation as a reliable renewable energy source
That said, it’s not uncommon to hear people claim solar energy isn’t as environmentally friendly as it is presented to be. While we admit that solar energy isn’t perfect, we do believe the green energy source has the power to transform the energy industry. Chariot Energy regularly conducts and shares research about solar energy technology and then implements that knowledge in our plans and services.
Despite what detractors might think, we want to ensure solar becomes even cleaner over time – and we’ll show you how that works.
Examining the Environmental Benefits and Challenges of Solar Energy
What Are Solar Panels Made Of?
The traditional process of manufacturing a solar panel begins with quartz, a very common mineral that can be found right in your home (if you have granite countertops)! Comprised of oxygen and silicon atoms, researchers discovered that this mineral can be converted into pure silicon for use as a semiconductor in solar panels to generate electricity.
Solar manufacturers historically mined quartz to supply the silicon for their solar panels. However, the mining of quartz crystal exposes miners to silicosis, a lung disease caused by inhaling tiny bits of silica from the ore.2 As a result, the solar industry is gradually moving away from quartz mining and toward quartz-rich sand.
Both quartz-rich sand and mined quartz can be refined into the same metallurgical-grade silicon for solar panels. At Chariot Energy, our solar panels are made exclusively from quartz-rich sand. In fact, one of our mottos is “From sand to solar!” This process ensures our solar panels never put people at risk of silicosis from mining.
The Challenges of Manufacturing Solar Panels
Here’s the challenge: in order to make metallurgical-grade silicon usable for capturing light, that quartz-rich sand must first be converted into polysilicon – another form of silicon with a different atomic structure. The chemical reaction that creates polysilicon produces a byproduct called silicon tetrachloride. If it isn’t disposed of properly, that new chemical can cause soil acidification and emit harmful fumes. Thankfully, scientists figured out how to recycle silicon tetrachloride back into polysilicon and reuse it in the production of even more solar panels!
Still, researchers continually look to improve this process and make it even more sustainable. China – where a growing portion of solar panels are made – has set regulations for manufacturers to recycle at least 98.5% of silicon tetrachloride waste.3 Moreover, scientists at the National Renewable Energy Laboratory, a division of the U.S. Department of Energy, are experimenting with alternative production methods that can avoid silicon tetrachloride altogether.4 With any luck, both of these strategies will result in a substantial reduction of waste – which will increase the stature of solar power as an eco-friendly source of power.
There’s an additional challenge: after polysilicon is purified, it’s formed into bricks then sliced into thin wafers, which comprise the “panels” in solar panels. Hydrofluoric acid (among other chemicals) are used to clean and texturize the panels to maximize light intake. While cleaning and maximizing the surface area is completely safe, like any chemical improperly disposed of, hydrofluoric acid can have a negative environmental impact.
Alternative Processes Currently in Development
While both the use of hydrofluoric acid and cadmium are being addressed through new technology and regulatory efforts, the future of solar panels will likely entail a switch to safer chemicals. For example, researchers at Rohm & Haas Electronic Materials, a subsidiary of Dow Chemical, have discovered that sodium hydroxide (NaOH), a safer and easier-to-use alternative, can be used instead of hydrofluoric acid. And since cadmium is toxic to plants, animals and micro-organisms, some manufacturers have switched to benign zinc sulfide instead.
Ultimately, even though chemicals have been around since the earliest days in the solar industry, the overall trend for regulators and researchers entails working together to first find better ways to dispose of these chemicals and to then use safer alternatives. Such challenges are innately present in all sorts of energy production – not just solar – so advancing the technology we use will have enormous potential in transforming the entire renewable energy industry.
What is the Carbon Footprint of Solar Panels?
Manufacturing Solar Panels
Electricity produced from solar yields no emissions, no greenhouse gases, and no fossil fuels, but it does require a certain amount of energy to make the solar panels. Luckily, the energy they produce far exceeds what it takes to manufacture them.
The solar power industry pays attention to these details by actively seeking ways to improve this power imbalance. In fact, researchers created a metric called Energy Payback Time (EPBT) to measure the length of time it takes a solar panel to generate the amount of energy equal to what it took to be created.
For multicrystalline-silicon systems (i.e. solar panels), it currently takes 4 years to achieve EPBT, according to the U.S. Department of Energy. 5 Since solar panels last for 20 to 30 years, a single solar panel can generate more than four or five times the energy used to produce. Even better, new technologies arrive every year to reduce EPBT even further. Eventually, the industry wants to shave years off of this time to truly maximize the value of solar!
Maintaining Solar Panels
Let’s address how much water is used to maintain solar panels vs. how much water is used to process fossil fuels. According to the Solar Energy Industries Association (SEIA), approximately 20 gallons of water per megawatt-hour (MWh) of electricity is needed to clean and wash solar panels.6 That’s less than the amount of water a typical family uses in a year, around 20,000 gallons of water, per the SEIA.
Compare that to coal processing.
Coal created all its electricity from the production of steam, so it naturally needs a lot of water to generate electricity. There are three options to cool coal plants: once-through, wet-recirculating, and dry cooling.
In the U.S., more than 90% of coal plants use once-through or wet-recirculating to cool.
- For once-through cooling, approximately 20,000 to 50,000 gallons of water is used to produce one MWh of electricity from coal.7
- For recirculation, 980 to 2,300 gallons are used to produce one MWh of electricity.
- This translates to 70 to 260 million gallons of water used each day for coal mining (washing and cooling drilling equipment), according to the U.S. Department of Energy.
That’s a lot of water, if we do say so ourselves.
Do Solar Farms Impact Wildlife?
The impact of solar farms on animal and plant life is an issue environmental and government groups alike have addressed since the technology was initially introduced. Not only does the solar industry continually seek to improve these conditions, but newer solar projects have received specific attention. 8
- At Chariot Energy, we conduct pre-clearing surveys to guarantee the safety of wildlife before our solar projects even begin. In addition, out dedicated team constantly monitors wildlife during projects and acts when necessary to avoid disturbing their natural habitats.
- California has a Desert Renewable Conservation Plan that prioritizes birds during the planning process.9 Other protective strategies include creating patterns on panels that discourage birds from flying into them and building habitat areas away from solar farms to attract birds and offset habitat loss.
In contrast to fossil fuel-generated electricity, solar panels are incredibly effective at maximizing electricity production while minimizing carbon emissions. In fact, carbon pollution and rising temperatures caused by fossil fuel extraction and generation have endangered 314 species of North American birds.10 Even though solar farms can temporarily displace local species, they produce cleaner energy that’s critical to the long-term future of all life on the planet.
Solar is One of the Cleanest Energy Sources Available Today
The American Chemical Society has extensively compared solar and fossil fuels, concluding that “Overall, all PV (solar) technologies generate far less life-cycle air emissions per GWh [gigawatt hour] than conventional fossil-fuel-based electricity generation” 11.
Also, the International Renewable Energy Agency and the International Energy Agency Photovoltaic Power System Programme released a joint paper explaining that, on top of far exceeding the energy payback time, over 90% of the materials in current solar panels can be recycled into the next generation 12. As the influence and impact of solar power grow, scientists and manufacturers around the world actively aspire to create even better, more sustainable solar energy technology.
Solar power is one of the most environmentally-friendly energy sources. That’s why Chariot Energy is passionate about providing solar power to Texas residents at rates that are competitive to traditional fossil fuel-generated electricity. We’re committed to the future of solar power – a safer, cleaner and greener future.
Check out one of our plans today!