The last decade has seen the solar industry come a long way. The global market was small in 2010 and highly dependent on subsidies in countries such as Germany, Italy, and the UK. In the last few years, the large-scale deployment of solar power has encountered a range of challenges. With ambitious price targets setting a high bar, rapid technological advances were needed to meet these expectations. Despite this the solar industry has excelled and solar installations were set to reach a record high in 2020.
According to the International Renewable Energy Agency, Global grid-connected solar capacity reached 580.1 GW at the end of 2019, along with 3.4 GW of off-grid PV. By the end of 2019, the US alone had deployed over 2 million solar PV systems, totalling about 71,300 MW of solar capacity, and generating over 100 TWh of electricity.
A study published by IHS Markit in early 2020 predicted that the global solar energy industry would record 14% growth in 2020 compared to the total solar capacity installed in 2019.They expected an additional 142GW to be installed during the year which is seven times that of the entire solar capacity that had been installed in 2010. Of course, back in January when the report was published none of us knew that the whole world would be afflicted by a pandemic. Though a recent assessment showed that the Covid-19 crisis is hurting global renewable energy growth it is not stopping it. In the US rooftop installations have been affected but the solar market has been remarkably resilient and is still expected to achieve record installations in 2020.
The Cost of Solar
The cost of solar has definitely fallen over the past decade. As new improvements in technologies promise to increase efficiency solar continues to become cheaper especially in sunnier regions where it has already become the lowest-cost form of new electricity generation. Given that solar is readily available and renewable it is possible that by 2030 solar could become the most important source of energy for electricity production in a large part of the world. At the rate, the solar industry is growing it won’t be long before solar energy is unbeatable in comparison to fossil fuels which will have a positive impact on the environment and climate change. Solar is easy and quick to install and is also very flexible giving it the potential to power something as small as a watch or as large as a city. Solar’s adaptability means that there is no reason why the solar industry shouldn’t continue to grow in the next ten tears.
The solar industry has very clear cost-reduction plans in place which should allow solar costs to be halved by 2030.
It is anticipated that silicon solar cells will continue to decrease in cost and be installed in large numbers. In the US, these cost decreases are predicted to increase the solar power generated by at least 700% by 2050! Meanwhile research on different designs for more efficient and less expensive solar cells will go on.
The Future of Solar Cells
Higher efficiency modules are already being developed today to enable the generation of 1.5 times more power than existing similarly sized modules using a technology called tandem silicon cells.
In order to outclass current solar cells a new design needs to be able to capture more light, transform light energy to electricity more efficiently and be less expensive to build than current designs. There is no doubt that the uptake of solar by energy producers and consumers will increase if the energy it produces is either equal to or less expensive than other non-renewable forms of electricity.
One option that allows solar cells to capture more light is to install electronics with the solar cell that let the cell track the sun as it moves through the daytime sky. If the solar cell is always pointing at the sun it will be hit by many more photons than if it was only pointing towards the sun around midday. Currently the cost of designing electronics that can do this accurately and consistently for several decades is prohibitive and presents an ongoing challenge. An alternative to making the solar cell itself move is to use mirrors to focus light on a smaller and therefore cheaper solar cell.
Another way of improving the way solar cells work is to target their efficiency so they are better at converting energy in sunlight to electricity. It has been proven that solar cells with more than one layer of light-capturing material can capture more photons than solar cells with only a single layer. Currently these cells are mostly too expensive and difficult to make for commercial use, but ongoing research may make it possible to implement these super-efficient cells one day.
Production innovations are in the pipeline that will decrease the amounts of expensive materials such as silver and silicon being used in the manufacture of solar cells. It is likely that if we were able to look into the future that we would see alternatives to silicon appearing on our solar farms and rooftops, helping to provide clean and renewable sources of energy.
One alternative to improving the efficiency of solar cells is to simply decrease their cost. Despite the fact that processing silicon has become less expensive over the years it still increases the cost of solar cell installation significantly. If thinner solar cells are used the cost of materials is less. These “thin-film solar cells” use a layer of material to harvest light energy that is only 2 to 8 micrometers thick, only about 1% of what is used to make a traditional solar cell. However, similarly to cells with multiple layers these thin-film cells are a little difficult to manufacture which limits their application, but research is ongoing.
Other innovations include the development of bifacial modules which allow panels to capture solar energy from both sides. Also, engineers continue to investigate ways of better integrating solar into our homes, businesses, and power systems. Better power electronics and a greater use of low-cost digital technologies are required for this.
The Sun Sets on Fossil Fuels
The transformation of the world’s energy supply away from polluting sources such as coal, oil and gas is being propelled by a number of different factors. One of the factors driving this change is political as in accordance with the 2015 Paris Agreement the world is intensifying its efforts to limit temperature rises to less than 2 degrees Celsius. Another important factor is the economic one as the cost of producing renewable energy has fallen considerably it is now competitive with other sources of power. A third force behind the changes is consumer demand with new technologies, such as solar PV and electric cars being adopted more and more.
Written by Janet Richardson from The Renewable Energy Hub UK