Are Solar Panels Really Good for the Environment?
Solar panels harness clean sunshine to create equally clean electricity. And unlike oil, gas, or coal, this energy generation doesn't emit any CO2 or other greenhouse gases.
The panels work silently in the background to produce pollution-free power.
However, are solar panels really as green as the industry would have you believe?
PV panels might generate clean electricity once installed, but getting them on rooftops requires a ton of extra steps, including extraction, manufacturing, and transportation.
- Each of these steps requires a lot of dirty energy.
- Each of these steps leaves a carbon footprint.
The question is – are solar panels a net positive for the environment or a net negative?
What Is the Energy Payback Period of Solar Panels?
Over a standard solar installation's lifetime, will the clean electricity produced ever equal the dirty energy invested to manufacture those panels?
The answer is yes. And the time that it takes to reach this breakeven point is surprisingly short.
According to the DoE, the solar energy payback period for multicrystalline silicon panels is about 4 years.
The exact length of time varies depending on several factors, including:
- Geography. On average, the energy payback period is shorter in sunny Spain than it is in the cloudy United Kingdom.
- Temperature. Solar panels actually work better in colder temperatures – up to a point. All things being equal, Canadian PV systems can generate more electricity per square meter than installations in the tropics can.
- Orientation. South-facing panels generate more electricity than North-facing ones (at least when installing panels above the equator).
- Quality. In order to reach these short energy payback periods, the panels must be high quality and installed by someone who knows what he or she is doing.
What Happens after the 4-Year Payback Period?
After the energy payback period, the system continues to generate clean electricity for decades. In most major markets, panels come with 25-year manufacturer warranties. So you should be protected for a minimum of 21 years after reaching the breakeven point. However, many installations can last a good 10 or 20 years longer.
Keep in mind that these numbers only apply to current solar PV technology:
- Energy capture rates continue to improve every year – i.e. solar panels are able to generate more clean electricity per square meter.
- Manufacturing processes are also becoming more efficient – i.e. companies are able to produce more solar panels using fewer resources and less energy.
This means that the energy payback period of solar will only become shorter in the years ahead. Better still, manufacturers will figure out how to extend the useful lifespans of the panels they create. Perhaps one day, warranties will come with 40-year guarantees or longer.Arjumand