Five Facts About Sustainable Solar Energy

By:Erin Mulligan Nelson

April 4, 2017

SunPower ground solar systems safely co-exist with agricultural uses including sheep grazing.

Editor’s Note: In 2020, SunPower announced the completion of the strategic spin-off of its manufacturing division into a separate business named Maxeon Solar Technologies, Ltd. As a result, SunPower has expanded its offerings to drive future growth. The SunPower Equinox® system now offers multiple panel options, including front- and back-contact panels, all of which are responsibly and rigorously quality tested to provide the best energy solution for your home. For more information on the differences in panel technology, visit our Better Solar Panels page.

Solar was the No. 1 source of new electricity generation in 2016, ahead of natural gas and coal, according to the Solar Energy Industries Association (SEIA) and GTM Research. In 2016 alone, the U.S. increased its solar (PV) installations by 95 percent, the highest growth rate on record.

While it’s exciting to see the growth of cleaner sources of electricity, not all solar is made with sustainable business practices. At SunPower, we aspire to be leaders in responsible green manufacturing. That means we build solar products that are as sustainable as the clean energy they produce. We accomplish this through what we call our “beneficial by design” product development approach and Light on Land™ practices, which minimize habitat loss, conserve water, reduce the use of environmentally sensitive materials and seek to avoid other environmental impacts.

We recently published our latest Sustainability Report, which details our accomplishments so far in becoming a sustainable company, so we thought now would be a good time to debunk five common myths about solar energy sustainability. 

Myth: Manufacturing solar panels uses more energy than they will generate.

Fact: While it may take fossil-fuel energy to create clean energy, it doesn’t require as much as one might think. We closely monitor what’s called “energy payback time” to calculate the time a panel needs to produce the equivalent amount of energy used during the product’s entire lifecycle — from sourcing raw materials to end of life.

According to the National Renewable Energy Laboratory (NREL), most commonly used photovoltaic solar panels have an energy payback time of less than four years and will produce a net gain of pollution-free energy of 26 to 29 years (assuming a 30-year lifespan).

SunPower® panels beat this standard with an energy payback time of about 1.2 years,1 and we’re continuing to speed up the payback with ongoing innovations in our manufacturing and environmental efficiency processes. For SunPower® Oasis® ground-mounted solar power plants, the energy payback time is even faster — just nine months.2 Since the useful life of our panels is expected to be more than 40 years,3 our panels produce net clean energy for 97 percent of their lifespan.

Plus, SunPower panels pair a lower degradation rate with the highest efficiency ratings on the market,4 producing up to 60 percent more energy in the same space over 25 years.5 That means homes and businesses can produce more power with fewer SunPower panels, which also reduces the overall environmental footprint.

Myth: Solar power plants use land that could be planted with trees or used for agriculture.

Fact: We, too, want to preserve natural resources, so we established our Light on Land solar development practices. We build on sites that have been previously disturbed, such as marginal agricultural land, rangeland, brownfield sites or landfills, with an emphasis on compatible dual uses such as sheep grazing. We also aim to restore land and soil to its original state while constructing and operating our projects, all while protecting native vegetation and animals. Check out this map of our sustainable solar power projects around the world.

SunPower’s high-efficiency Oasis solar power plants also maximize land use, generating 34 percent more energy per acre than a plant built with conventional solar technology. Our latest version of our Oasis solar solution features tracker rows wide enough to accommodate a tractor, with the aim of using power plant sites for both energy and agriculture. SunPower has partnered with the University of California, Davis, a global leader in agricultural studies, to study co-location of agriculture with Oasis technology and to evaluate possible crop varieties and yield.

Myth: Solar panels are made of toxic materials that are harmful to humans.

Fact: SunPower aims to minimize environmental impacts at every stage of the product lifecycle and we are committed to transparency. We voluntarily adhere to the International Organization for Standardization’s environmental management practices, achieving a 14001 certification, which helps organizations improve their environmental performance through more efficient use of resources and reduction of waste. We are also committed to ensuring our products comply with material content requirements, including the European Union’s Restriction on Hazardous Substances (RoHS) Directive.

Additionally, SunPower is committed to ensuring our products and components are free from harmful substances, such as lead or cadmium. As a result, our E-Series and X-Series DC solar panels do not require hazardous waste handling procedures during the recycling process. SunPower’s Supply Chain Sustainability Program also helps suppliers meet our environmental, health, safety, labor, ethics and chemical content requirements.

And we now feature a Declare Label on our panels that tells exactly what they are made of

Myth: Solar panels use too much water to generate electricity.

Fact: With recent drought conditions across the U.S., water conservation is a top environmental concern. Unlike concentrating solar thermal plants that require water for cooling, solar PV systems do not use water for generating electricity. However, as in all manufacturing processes, some water is used to manufacture solar PV components, but it’s far less than is used to generate traditional electricity.

Water is also used to clean solar panels. Solar equipment, especially on large solar installations, needs to be cleaned regularly to remove dust and optimize energy production. SunPower’s cleaning robots can handle this chore more efficiently, using 75 percent less water than manual cleaning.6 Learn more in our recent blog post Water and Energy: Solar Conserves a Precious Resource.

Myth: Solar panels can’t be recycled.

Fact: Most of the solar power in the U.S. was installed within the last decade and has a life expectancy of 30 years or longer, but it’s still important to prepare to recycle solar panels. Because recyclability is a growing concern, in 2016, we worked with SEIA to develop the first industry-wide PV recycling program. Together with other solar companies, we are creating a national network of recyclers who can responsibly manage PV waste to prevent environmental impacts and to keep it out of landfills. Building this infrastructure will make it easier to recycle the panels at end of life.

Get the latest on SunPower’s sustainability efforts in our 2022 Environmental, Social and Governance Report.

1 De Wild-Scholten, M. (2013). Energy payback time and carbon footprint of commercial photovoltaic systems.  Solar Energy Materials and Solar Cells, 119, 295–305

2 Francke, L, et al. (2015). GHG Emission and Energy Payback Time of AC Electricity Generated by SunPower® Oasis® Photovoltaic Power Plant. 42nd IEEE PVSC”

3"SunPower Module 40-Year Useful Life," SunPower white paper. 2013.  Useful life is 99 out of 100 panels operating at more than 70% of rated power._

4Based on search of datasheet values from websites of top 10 manufacturers per IHS, as of January 2017.

5SunPower 360W compared to a Conventional Panel on same sized arrays (260W, 16% efficient, approx. 1.6 m2), 4% more energy per watt (based on PVSyst pan files), 0.75%/yr slower degradation (Campeau, Z. et al. "SunPower Module Degradation Rate," SunPower white paper,  2013).

6Based on experience with robotic cleaning at actual SunPower sites, compared to data tracked by subcontracted manual cleaners utilized at a SunPower project.