With Earth Day 2021 in the rearview mirror, this seems like a good time to examine the environmental impact of solar panels.
On the one hand, solar energy is changing the paradigm of power generation and consumption for the better. But on the other hand, homeowners may have concerns that the materials and methods used to make the cells and panels can in some way harm the environment, which would cancel out the benefits of decreasing their carbon footprint and helping the planet.
That’s certainly a valid concern. After all, if solar panels require a massive amount of carbon dioxide (CO2) to produce, how long would you have to reduce a home’s power consumption to make up for the greenhouse gasses emitted into the environment? In that vein, let’s take a closer look at how solar panels are produced and what their carbon footprint looks like.
How Much CO2 Does Your Home Produce Now?
Thanks to the state’s solar and other renewable energy sources, Nevada is one of the lowest CO2 emissions producers in the country. The state emitted only 36.7 million metric tons in 2016, according to Choose Energy. By way of comparison, the highest producing state, Texas, emitted 653.8 million metric tons in this same study. Here in Nevada, residential CO2 emissions represented 22.8 percent of statewide emissions in 2014, according to the
Clark County Regional Emissions Inventory.
For an average home, a single kilowatt hour (kWh) of electricity produces a little over one pound of CO2. A typical home uses about 900 kWh per month, or 30 kWh per day. To calculate a monthly carbon footprint of your power consumption, multiply the CO2 of one kWh by your monthly usage, which can be obtained from your service provider.
Emissions Concerns About Solar Panels
It’s difficult to calculate the emissions from the production of any manufactured good. The carbon cost may include mineral discovery, extraction, transport, manufacturing and assembly and transport of the product, installation, and many other factors.
One major concern with the manufacture of solar panels is the carbon debt created by all the elements that go into it, as noted above. Additionally, fabricating the panels may utilize caustic chemicals like hydrofluoric acid and sodium hydroxide. Another concern is where the electricity comes from – some solar panel factories may draw electricity from Chinese coal-fired power stations, a notorious air pollutant.
How Much CO2 Does It Take to Produce Solar Panels?
As with most manufacturing processes, some CO2 is released in solar panel production. Because solar panels are silicon based, high levels of heat must be used for correct shaping, which leads to the CO2 release. In general, their production generates approximately 40-50g of CO2 per kWh.
Although this number is significant, it’s important to understand that it’s dwarfed by the carbon output of coal-powered electricity sources by about 20 times over. What that means for you is it will take about three years of operation before they become carbon neutral. So what creates the carbon footprint of solar panels?
Mining is certainly a contributing factor. The mining industry itself generates annual CO2 emissions of up to 5.1 gigatons. Some of the many materials mined to make solar include copper, lead, iron, nickel, silver, zinc, aluminum, and indium. Mining also has other negative environmental impacts such as erosion, loss of biodiversity, sinkholes, and soil/groundwater/surface water contamination.
As mentioned earlier, manufacturing in general produces about 50g of CO2 per kWh, which means that in three years the panels will become carbon neutral. The good news is they stay that way for the rest of their life span, which is typically 25 years or more.
The great news is that although they produce some CO2 in their manufacture, their carbon debt is still 20 times less than coal-powered electricity sources. You massively reduce your carbon footprint simply by installing and turning them up.
The transportation sector emitted around 1.9 billion tons of CO2 equivalent in 2017, according to data from Yale University. Transportation consists of cars, trucks, boats, planes, and trains, any of which may be used to move solar parts or panels to and from various stages of manufacturing and to their final destination.
A 2020 study in Our World in Data found that transportation accounts for about one-fifth of global CO2 emissions. Using statistics from the International Energy Agency (IEA), 29.4 percent of these emissions come from freight-hauling trucks, while aviation made up 11.6 percent. Rail freight amounted to only 1 percent of transport emissions.
What’s a Carbon Debt and How Long Do Solar Panels Take to Pay It?
Carbon debt can be described as the imbalance between the carbon output (or “footprint”) and any offset put in place to counteract it. This could apply to a person, business, industry, or country. Some skeptics of solar argue that renewable energy, including nuclear, hydro, bioenergy, and wind have a carbon footprint “hidden” in their manufacture or construction.
If renewables have a hidden carbon footprint, then it’s hiding in plain sight. Yes, solar panels have a carbon debt, and they require three years in operation to pay off this debt. Once that’s paid off, solar becomes carbon neutral for the remainder of its lifespan. From there, its benefits become obvious – lower electricity bills, a healthier planet, and a happier Mother Earth.
Do Solar Panels Have Lower Lifetime Emissions Than Conventional Utilities?
A 2017 study published in Nature Energy shows that for each kWh of electricity generated over the lifetime of solar panels, the carbon footprint is about 6 grams of CO2 per kWh. This is slightly more than what is generated by nuclear and wind energy (4g) but far below coal (109g), gas Carbon Capture and Storage (CCS) (78g), hydro (97g), and bioenergy (98g).
Nature Energy’s research looked at the full lifecycle of greenhouse gas emissions from a wide range of power sources all the way through the year 2050, when it’s anticipated that global electricity supplies will be mostly decarbonized. The study considered emissions from manufacturing, construction, and fuel supply and found that even with these elements included the carbon footprint of solar is many times lower than gas or coal.
One factor to consider in these numbers is the efficiency of solar in some locations compared to others. For example, here in sunny Nevada the best solar technology has a footprint of just 3 grams of CO2 per kWh, which is seven times lower than the worst solar technology found in poor locations with little sunshine (21g). Still, solar comes out with an extremely minimal footprint compared to other power sources.
What Are the Other Environmental Costs of Solar Panels?
In general, solar systems are good for the environment. During operation they don’t produce any air pollution or greenhouse gases. Other nonrenewable energy sources have a far greater negative impact on the environment and the planet benefits when solar energy replaces them.
However, there are some other environmental costs of solar that should be considered. The production of solar panels and their necessary inputs can be harmful to people living near and the environment around mines and factories. Older solar panels may contain toxic materials like lead that can leach into landfills and contaminated sources of groundwater.
How Can Solar Panels Benefit You?
One of the main reasons people choose solar is because it saves money…a lot of money. Electricity here in Nevada isn’t cheap. Solar energy harnesses the almost “always on” free rays of the desert sun and converts this to energy that powers your home. This can dramatically lower your energy bill.
Here are some other advantages for homeowners:
- Increases your home’s value
- Solar panel incentives like tax credits and rebates
- Sustainable, renewable power
- Ability to sell excess power back to your energy provider
Businesses may also enjoy:
- Becoming a “green” business to increase community goodwill
- Reduced operating costs
- Defending against utility rate changes
Want to Save Money, Protect the Environment, and Improve Your Health? Contact Bell Solar Today!
There’s an old acronym used in Economics 101: “TANSTAAFL”, or “There Ain’t No Such Thing as a Free Lunch.” This is true of solar. Is it carbon neutral from the start? Of course not, nothing really is. Can solar power save you money, dramatically help the environment, and create a healthier world? It absolutely can. Contact Bell Solar today to learn how!