Should Renewables Be Considered "Green"?
Do wind and solar do more harm than good?
The recent documentary “Planet of the Humans” posits a seemingly simple solution to saving the planet from the effects of climate change. Jeff Gibbs' and Michael Moore's film essentially asserts that because no source of energy is perfect, they're all bad. The film leaves viewers feeling that humanity itself is the problem, and offers very few positive solutions to existential catastrophe other than a drastic decline in human population, consumption, and economic growth.
So does renewable energy cause more harm than good? Do the environmental and human costs of producing wind turbines and solar panels outweigh their lauded benefits?
The necessity of zero-emissions
Contrary to the assertions of Moore and Gibbs, scientists across the globe have reached near unanimous consensus that reducing carbon emissions is essential to stave climate catastrophe. According to the IPCC, humanity must reach net-zero emissions by 2050 or else risk a climate crisis. Following Gibbs' and Moore's solutions, this will be impossible, because no matter how reduced human population and consumption become, carbon will still be produced. What is more, the carbon currently in the atmosphere and oceans will continue to wreak havoc on the climate for decades to come. The only solution to stopping emissions and employing technology that draws carbon from the ocean and atmosphere is to create clean energy to power a carbon-negative economy.
What role does wind and solar have in reducing emissions?
The Kaya Identity is a formula developed by energy economist Yoichi Kaya to lay a framework for focused carbon-reduction strategies. The simple formula is as follows:
F= Human carbon emissions
P= Human population
G= Economic activity (GDP)
E= Energy consumption
For F (human carbon emissions) to be zero, either P, G, or E have to be zero. So to reach zero emission, either:
Get rid of all humans on earth (P)
Remove all energy that powers the economy (E/G)
Eliminate carbon from energy production (F/E)
Obviously, the first two choices are out of the question, leaving zero-emissions energy as the only option for obtaining a net-zero civilization.
The greatest contenders for a low to no carbon energy source are solar and wind, and they have the potential to scale rapidly in order to provide the vast majority of the United State's energy by 2030, and all of it by 2045.
But the fact still remains that solar and wind energy come at some cost to people and the environment.
Does solar and wind energy hurt the environment?
There's always a cost to everything. Even though solar panels and wind turbines produce free green energy, they are energy and resource intensive to produce. Solar panel production requires large amounts of energy and harmful chemical processes, all of which harm the environment and people if not adequately controlled.
However, when it comes to creating renewable energy technology, it's a toss up between the lesser of two evils. Yes, making renewable energy requires significant carbon emissions and produces potentially dangerous byproducts. But emissions associated with production and transport are quickly offset by the large amounts of clean energy they produce rather quickly.
The total carbon footprint of a product, otherwise known as “embodied carbon,” is the total carbon dioxide emissions equivalent (CO2e) associated with its production, transportation, installation, and use.
Thus, to measure the climate impact of a wind turbine or solar panel, a thorough life cycle analysis (LCA) has to be conducted. Thankfully, the LCAs are out there, and they certainly don't condemn alternate energy.
What is the embodied carbon footprint of solar?
No equivocation here: solar panel production produces a lot of carbon. The total carbon footprint of a typical residential solar array is formidable five tons of CO2e. But as a 2018 paper in the Energy and Buildings journal clarifies,
“It should be noted that although there is a significant embodied CO2e footprint for some sustainable energy technologies, this does not indicate that they are poor options. The savings made during the use (operational) stage can and do overshadow these results.”
The paper goes on to explain how quickly the carbon footprint of solar panels can be offset and exceeded:
A solar array on a typical home will save nearly a ton CO2e/year.
- A typical 2.1 kW home solar array with an embodied carbon footprint of five tons will offset its carbon footprint in 5 years.
Every kWh produced in the U.S. produces one pound of CO2. Considering the typical solar array cited in the Energy and Buildings paper produces roughly 1720 kWh/yr, this solar array will produce additional operational savings of 1720 pounds of CO2 every year.
Solar panels are getting more efficient, too, with some panels paying back their carbon footprint within 2-3 years, and some payback estimates as low as 1.5 years. With a 20-30 year lifespan, the average solar panel sequesters 15 to 23 tons of CO2e in its lifetime.
What is the embodied carbon footprint of wind?
Like solar panels, wind turbines require varying degrees of fossil fuel inputs which lead to carbon emissions: raw materials have to be extracted and transported to a factory, components need to be transported, and the finished unit has to be assembled. But despite the massive size of modern utility-scale turbines, they are carbon-offsetting superheroes.
A study from UK and Australian scientists estimated the embodied carbon footprint of 14 wind turbines from 50 kW (small) to 3.4 mW (utility scale):
Carbon footprints rise as turbine size and output increase.
- Larger turbines offset their carbon footprint quickly: A 3.4 mW turbine had a carbon footprint 1046 tons CO2e, but offset its footprint in just 64 days.
Wind energy pays off its carbon debt much faster than solar, making it among the first choices for decarbonizing energy. Larger turbines offset their carbon footprints faster than smaller turbines, so installing utility-scale wind farms makes more sense from a carbon perspective.
A 3.4 mW turbine will produce 154 million kWh in its 20 year lifetime, providing a net savings of 77,000 tons of CO2e.
Are solar panels ethically made?
Solar panels require certain common and rare elements. Some of these elements – particularly gold, tantalum, tin, and tungsten – are categorized as “conflict minerals,” whose extraction fuels violent conflict in source nations (particularly the Democratic Republic of Congo and neighboring countries).
According to the UK organization Ethical Consumer, nearly all of the large solar companies source their rare raw materials unethically. Only solar producers Sharp and Kyocera receive middle ratings for ethical material sourcing, as they have committed to conflict-free sourcing within the DRC.
Other factors should be considered in ethical production. For example, solar producers Hanwha, Tata Groups, and Mitsubishi produce military weapons technologies, and Mitsubishi sells nuclear fuel for energy production.
Solar panels unfortunately require materials that are ethically ambiguous in light of current geopolitical realities. Questionable sourcing of raw materials is a wake up call for the solar industry to create products that are not only good for the environment, but also promote justice and equity.
Are wind turbines ethically made?
Relatively little third-party information exists on the ethical sourcing and production of wind turbines. However, the world's largest turbine manufacturers – Vestas, Siemens Gamesas, and General Electric – do outline their sourcing and ethics ethos individually.
Vestas has ethical sourcing of materials and protection of human rights embedded in its procurement strategy. If breaches in ethical sourcing are found, Vestas demands suppliers ameliorate the breach or lose Vestas' business.
Siemens Gamesas outlines a comprehensive procurement strategy that bars unethical sourcing and any practices breaching the company's Code of Conduct. The company's supply chain management principles require third-party audits of suppliers' sustainability and ethics practices, ousting any supplier that consistently fails to abide by the Code of Conduct. Siemens Gamesa even provides original purchasing agreement documents for view on their website.
GE is not as transparent as its two top contenders. The company has a generic ESG/CSR Page for the company as a whole, but lacks one for its renewable energy division. The company's 2018 ESG report does offer some sourcing insight for the company overall, but not for its renewable energy wing exclusively. The report admits that it sources its materials from regions that are ethically ambiguous. The company does expect its suppliers to refrain from force, fraud, coercion, or imprisonment of workers, and conducts yearly audits on its suppliers. In 2018, for example, GE ran 2,509 individual audits with its suppliers, finding nearly 19,000 violations.
Solar and wind energy come at a cost. There is certainly a carbon footprint associated with the production of both, and solar panel sourcing in particular raises significant ethical issues.
However, it's imperative to rapidly decarbonize in order to avoid potentially catastrophic warming. Energy represents 32 percent of all greenhouse gas emissions in the United States. Reaching carbon neutrality through clean energy not only cuts this share down to zero, but provides the energy necessary to scale other technologies necessary to remove more carbon from the atmosphere and the ocean than humanity produces.
The carbon footprint of solar and wind are quickly offset by the clean energy they produce. The human rights implications of sourcing and producing these products, however, needs to be addressed. While the world continues to invest in alternative energy, consumers, producers, and stakeholders must ensure ethical sourcing, production, and end-of-life processing to ensure clean energy doesn't perpetuate oppression and injustice.