Solar panels have been a major game changer for the power generation industry and have disrupted the utility sector as we know it.
Renewables are punted as a solution to many of our energy challenges, ranging from energy poverty to global warming. Advances in technology, government policies and increased competition have enabled solar power to go mainstream.
Since the demand for solar power has increased, manufacturing of solar panels has also increased exponentially.
In 2007 worldwide solar power capacity was around 2.5 GW; fast forward to 2018 and global capacity is sitting at 86 GW.
Forecasts predict these figures will further increase to 110 GW by 2022! Much of this demand will likely come from the developing world as solar becomes more cost-effective.
As the demand for solar power increases, so does the demand for resources such as silicon, metals and even the energy used to manufacture solar panels.
But just how much energy is required to manufacture a solar panel and what happens to solar panels at the end of their useful lifespan?
Are they dumped or recycled and if the latter how much of a solar panel is recyclable?
What Is Embodied Energy And How Does It Relate To Solar Panels?
First, let’s get familiar with the terms such as embodied energy.
Embodied energy is the sum of all the energy required to produce any goods or services, considered as if that energy was incorporated or 'embodied' into the product itself.
The concept is useful in determining the effectiveness of energy-producing or energy-saving devices.
One fundamental purpose for measuring this quantity is to compare the amount of energy produced or saved by the product in question to the amount of energy consumed in producing it.
What’s included though, when calculating the embodied energy of a solar panel?
At a minimum, the energy to mine the materials, run the factories and ship the panels to the end user should be included.
Now, depending on the type of panel used and the solar irradiation available where installed, that embodied energy in the panels will take 2-4 years to pay back.
Solar panels have a typical lifespan of 30 years so the panels’ lifetime energy output should be 10 to 20 times the energy it cost to provide them.
A recent study was conducted on the greenhouse gas emissions emitted through the mining of solar panel materials to the manufacturing of these solar panels and the energy mix used to manufacture these panels.
The study focused on four different types of solar panels. Namely thin-film, multicrystalline silicon, monocrystalline silicon and ribbon silicon. Out of these scenarios, one is based on the average European energy mix, another on the average American energy mix.
Thin-film solar panels win the mix with 20.5 grams of CO2 in the European energy mix and 25 grams of CO2 in the American energy mix.
The main reason here is due to thin-film panels requiring less material and no aluminium frame.
Monocrystalline silicon cells fair the worst with 43 grams of CO2 in the EU, and 55 grams of CO2-equivalent in the US.
How is this calculated?
Some assumptions such as the amount of sunlight that the cells receive and the expected lifespan of the solar panel are made here. European averages are used in calculating the carbon footprint. Next, the amount of CO2 emitted for the production of one square meter of solar panels by this lifetime electricity generation.
Solar Panel Recycling
Solar panels have a long lifespan of 30 years which is a long time by any standard. But what happens after these solar panels have reached their end of life?
Ditching these panels at a landfill site isn’t an option. E-waste is becoming a major issue as electronics impact every avenue of our lives and ends up leaching toxic chemicals into our soil and respective underground water reservoirs.
Solar panels are made up of aluminium, glass, silicon cells, synthetic materials and other metals. As solar power has exploded in recent years we can expect a huge solar panel e-waste challenge a decade or two from now. For now, the demand for solar panel recycling is relatively small but this will change.
By the end of 2050 5.5 million to 6 million metric tons of solar PV waste is expected each year. Most of this waste is expected to come from China.
With these challenges comes the opportunity to develop a solar panel recycling market. The first solar panel recycling plant has just opened in France.
The plant is expected to recycle 1,300 tonnes of solar panels in 2018. This is expected to increase to 4 000 tons by 2022.
Many of the largest solar panel manufacturing companies are focusing on improving the recyclability of their solar panels when they reach the end of life.
In the recycling of solar panels, the previous recovery rate for silicon-based panels was around 90%. A European solar panel recycling association has now developed technology that can recycle up to 96% of a solar panel. The remaining e-waste is used in an energy recovery process, using a waste-to-energy technology.
In Australia, there’s only one solar panel recycling company at the moment and they are looking to scale up due to the expected increase in demand for recycling of solar panels.
For now, most of the solar panels being recycled are damaged or faulty panels. But, at least the recycling infrastructure for solar panels is being put into place.
Solar Panel Companies Pushing the Boundaries in Manufacturing Sustainability
Solar panel companies mindful of the impact solar panels will have on e-waste and the embodied energy their solar panels have, are innovating in this space. This includes using innovative production techniques to reduce production energy consumption. Other techniques also maximise resource efficiency and reduce product wastage.
GCL is one perfect example. By using pressurised cryogenic recovery technology, they can fully recycle the silicon tetrachloride, hydrogen chloride and hydrogen that are produced during the production process.
Through technological innovation, they’ve solved such problems as maximising utilisation of resources and non-hazardous disposal of byproducts such as silicon tetrachloride, hydrogen chloride, waste gas and waste liquor generated in polysilicon production, and realised material recycling and "zero emission".
It makes perfect sense that companies in the clean energy space ensure their business practices include manufacturing processes that embrace sustainability and its core values.
SunPower has taken a step further down the supply chain by achieving cradle to grave status for their E-Series/X-Series solar panel range.
We hear you ask what does “cradle to grave” mean? In the materials management and business world, cradle to grave means the impact a product or service has from an environmental perspective from the beginning of its lifecycle to its disposal.
Now SunPower claims to be the first Silver Certified Cradle to Grave Solar PV manufacturing company. This includes sourcing materials safe for humans and the environment and ensuring these materials are recycled at the end of their lifespan.
They honour the natural environment and the people who create the product, as well as the use of renewable energy and the preservation of water.
Renewables have achieved a lot in moving towards a low carbon economy, providing cheap access to electricity and alleviating energy poverty. Demand for solar power is expected to reach an all-time high of 110 GW in 2022.
However, with an increasing demand comes to an increasing environmental impact. The embodied energy, which is the amount of energy used to produce a solar panel generally, has a payback time of 2 to 4 years depending on the location in which the solar panel is installed.
CO2 emissions per panel also range from 20.5 grams of CO2 to 43 grams of CO2 depending on the type of panel and where it was produced.
With the boom in solar power, solar panel waste is expected to increase as existing solar panels reach the end of their lifespan.
At present solar panel recycling infrastructure is limited to recycling mainly damaged or faulty panels. However, recycling capacity of solar panels is being developed to cater for the increased demand for solar panel recycling.
Solar panel manufacturing companies like GCL in the spirit of sustainability are improving the efficiency of solar panel manufacturing from reducing the amount of energy required to a produce a panel, to reducing wastage of materials and recycling of production by-products.
SunPower has taken it a step further by including the entire supply chain and has been awarded the Silver Cradle to Grave certification. Expect solar panel companies to become increasingly aware of their impact on the environment.
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