Going solar is lauded as the best thing you can do for the environment. But is solar energy really clean and green as it is made out to be?
The answer to this question is not simple and straightforward. There are many facets to the problem that need in-depth analysis and understanding.
To calculate the environmental impacts of solar power, we need to consider the technology and hardware separately. The process of generating electricity using solar panels is indeed clean and green. However, other aspects of solar panels such as the procurement of raw materials, manufacture, transportation, and installation are neither clean nor green.
But the question here is how damaging are these processes to the environment? Do the positives and negatives balance each other out? Does solar power have a net carbon debt?
Read on to learn about the carbon footprint of solar production and how it impacts the environment. In this article, you will also find ways to minimize your carbon footprint when going solar and what the future holds for solar energy.
What is the Carbon Footprint of Solar Panel Manufacturing?
Solar power is classified as a clean and sustainable energy resource. The process of generating electricity from sunlight doesn’t produce harmful carbon emissions or pollution. This is the reason why solar energy is at the forefront of our fight against global warming and climate change.
However, the story doesn’t end there.
The hardware, especially the solar panels, used in the solar system does come with carbon footprints. Carbon footprint is defined as the amount of carbon dioxide released into the atmosphere as a result of activities.
The production process involved in the generation of solar energy – from the mining of rare earth minerals and metals and their transportation to the manufacturing process of solar panels and the remaining components of the solar system, their transportation from the place of manufacture to the place of installation, and the process of installation – all contribute to carbon emissions.
We need to consider several factors while calculating the solar carbon footprint. The first and foremost is the type of photovoltaic panel chosen. How the raw materials used in its production are obtained, how the panels are made, how they are transported, and the expected lifespan of the panel. Even the way the panels are disposed of can make a difference.
Types of solar panels
There are 3 distinct types of solar panels used today, each coming with a different carbon footprint as the materials used, efficiency levels, and production process differ.
- Monocrystalline silicon
- Polycrystalline silicon
Monocrystalline panels are made from a single silicon crystal, sliced into thin wafers. Polycrystalline panels are made by melting silicon crystals, cooled in a mold, and sliced into thin wafers.
Thin-film panels are made from a range of materials, the prominent among them being cadmium telluride (CdTe), amorphous silicon (a-Si), and Copper Indium Gallium Selenide (CIGS).
Besides the materials used in the solar panel production and the manufacturing process itself, another important feature of these panels affecting their carbon footprint is their efficiency levels. While monocrystalline comes with the highest level of efficiency of 22%, the efficiency of polycrystalline is 18%, and that of thin-film panels is 11%.
As described above, the raw material used in the manufacture of each type of photovoltaic panel is different. In addition to the main component, a solar panel also uses rare earth minerals and precious metals like copper, silver, indium, and tellurium. Besides these, lithium is used in solar batteries.
Mining these minerals involve the emission of greenhouse gasses, resulting in a carbon footprint. Transport of these minerals to the place of manufacture ends up adding more carbon footprint.
Manufacturing and Transportation
The solar panel manufacturing process involves heating these minerals to high temperatures in an electric furnace. Most often coal, a fossil fuel, is used in the production as energy for the electric furnace. This adds to the carbon footprint of solar energy.
There is another angle to this. The location of manufacture plays a huge role in the solar panel carbon footprint. Because guidelines for manufacturing vary from country to country. China has become the hub for solar panel manufacturing in the past two decades. Unfortunately, the fuel used there is mostly coal, while in the US and Europe, a fair share of it comes from renewable sources.
Transportation is another step where solar panels end up accumulating more carbon footprint.
Lifespan of a Panel
Lifespan is another major factor to calculate the carbon footprint. This can be anywhere from 15 to 30 years.
The time taken for a photovoltaic panel to pay back the carbon debt is between 1-3 years. Carbon debt relates to the carbon footprint of the solar panel. It depends on how much carbon footprint the solar panels accumulated during various processes.
The payback period for carbon debt depends on the amount of sunlight received by the panel and the quantity of electricity it generated. Once the panel has paid its carbon debt, for the remaining years, the panel will produce carbon-free electricity.
Disposal of the decommissioned panel
The carbon footprint of a solar panel doesn’t end when it pays back the carbon debt it accumulated during production and transportation. The disposal of the panel at the end of its life cycle is equally important.
As solar panels contain rare earth minerals and precious metals that can be recovered, proper recycling arrangements can reduce its carbon footprint. Another disturbing trend in recent times is the tendency to replace or discard panels before their lifetime.
The reasons for this are numerous. Incentives for newer installation, decreasing efficiency level of older panels, higher efficiency levels of new technology panels, or reluctance of the solar companies to repair damaged solar panels – all these ends up compounding the problem.
10 Negative Environmental Impacts from Solar Panel Manufacturing
Each stage of the production process, transportation, and finally the disposal of solar panels has environmental impacts in addition to the carbon footprints it creates.
Mining raw materials
1. Mining is an energy-intense process mostly involving fossil fuels like coal.
2. Solar panels require rare earth minerals and precious metals, besides raw materials for glass, framework, battery, and other components. Mining depletes these finite natural resources. As the demand is high for these minerals and metals, they are mined without considering the environmental consequences.
3. Some of the serious implications of mining are loss of biodiversity, formation of sinkholes, and contamination of neighboring water bodies from highly acidic metal waste.
Production and transportation
4. The solar panel manufacturing process is resource-intensive, with high demands for energy, water, and industrial materials.
5. Hydrofluoric acid and sodium hydroxides used in the process results in toxic water that needs to be disposed of with care.
6. In the manufacture of polycrystalline panels, hydrochloric acid and hydrogen are used, resulting in a highly toxic by-product, silicon tetrachloride. For each part of pure silicon, three-to-four times silicon tetrachloride is produced.
7. Another harmful by-product of the process is silicon particles. These are released into the air during the production process, leading to silicosis in people exposed to them.
8. When vehicles using fossil fuels are used in the transportation of raw materials and finished goods, the resulting GHG emissions are bad for the environment.
Solar waste and pollutants
9. Although some of the materials used in solar panel production can be recovered and reused, this is rarely done as this is a tedious and expensive process. Lead and cadmium used in panels are carcinogenic, raising safety concerns.
10. At present, there is no policy to regulate the recycling of panels, they are left in landfills. This poses a real environmental risk due to the toxic chemicals present in them. Rainwater can transfer these toxic substances to land and water bodies, leading to pollution.
How much carbon emissions are generated during solar panel manufacturing?
It is estimated that solar panels generate about 50g of carbon dioxide per kilowatt-hour during the first few years of operation. For the solar panels to break even on the carbon debt and become carbon neutral, it will take 1-3 years of operation.
For the remaining years, the solar panel will remain carbon-neutral and continue to generate carbon-free energy. Since the life cycle of solar panels is considerably long, that is a lot of carbon dioxide kept out of the atmosphere.
When compared with coal-powered energy, the carbon debt of solar energy is 20 times lower.
How Do We Reduce Greenhouse Gas Emissions?
While some of the processes leading to GHG emissions can be improved, modified, and made more efficient, we can’t do much about some others.
As newer technologies are developed and newer materials are discovered in the manufacture of solar panels, we can hope to bring down the use of energy and the use of depleting natural resources. With more care, we can hope to avoid contamination of water sources and loss of biodiversity during mining.
Ensuring that the energy used in the production process is cleaner, it is possible to control the damage to the environment.
By framing environment-friendly policies and strictly implementing them, we can learn to dispose of toxic by-products of the manufacturing process responsibly. Improvement in manufacturing technology can control the release of silicon particles into the air.
Developing better technologies to prolong the life cycle of solar panels can help in bringing down the solar carbon footprint as well as their harmful impact on the environment.
Recycling is the best way to deal with solar waste. Though this is again an energy and resource-intense process, it can help save precious natural resources and prevent production pollution of the environment.
In the past decade alone, the technology involved in the manufacturing of solar panels has evolved so much. From the materials used and the method of production to the efficiency and lifespan of solar panels, there has been a constant change for the better.
Solar panels come saddled with a considerable carbon footprint, although solar power generation is a carbon-neutral process. However, when compared with coal-powered energy, this is too negligible.
As the world is aiming for a carbon-neutral approach, more research and development must continue in the field so that better technologies are developed to minimize environmental fallouts. Improving standards and practices can help in reducing the impact as well as equitable distribution of inevitable environmental fallouts.
In the meanwhile, let’s continue to encourage solar power as its net carbon debt is insignificant in comparison with energy from fossil fuels.