What is the future potential for solar?
Solar panels on a UK roof [Image: Elliott Brown, Flickr]
In an article for TechInsider last year, Rebecca Harrington noted that the world would only need a land surface area about the size of Spain in order to meet global electricity demand in 2030, based on solar panels with a 20 percent efficiency level. How accurate is this and what does the future look like for solar power?
That figure was actually produced by The Land Art Generator project which dedicates itself to advancing the deployment of sustainable design solutions. It calculated: “678 quadrillion Btu (the US Energy Information Administration’s estimation of global energy consumption by 2030) = 198,721,800,000,000 kilowatt-hours (simple conversion) divided by 400 kilowatt-hours of solar energy production per square meter of land (based on 20 percent efficiency, 70 percent sunshine days per year and the fact that 1,000 watts of solar energy strikes each square meter of land on Earth) = 496,805 square kilometers of solar panels (191,817 square miles [roughly the size of Spain]).” It is encouraging because it is only discussing solar, not taking into account all the other forms of renewable energy generation from hydropower to wind, to wave and tidal and so on.
According to the US Department of Energy, solar panels with an efficiency level of about 10 percent covering 0.16 percent of the Earth’s land area would generate energy equivalent to that generated by 20,000 1 gigawatt equivalent (1 GWe) nuclear fission plants. The DOE adds that this number of plants would need to be constructed in the second half of the 21st century if carbon sequestration proved to be non-viable and if solar energy wasn’t developed. This is taken from a DOE publication published in 2005. Hopefully, the world has come a long way in solar power development since then.
Installing solar panels on a ground mount [Image source: Oregon Department of Transportation, Flickr]
Actually, it has. For example, in late April to May last year three solar cell efficiency records were broken in just four days. Trina Solar announced on April 24th that it’s Solar Honey Plus multi-crystalline silicon module had achieved 19.4 percent. This was independently confirmed by the National Center of Supervision and Inspection on Solar Photovoltaic Product Quality (CPVT) in Wuxi, China. Shortly afterwards, on April 27th, German company Manz achieved 16 percent on its commercially-produced copper indium gallium selenide (CIGS) solar modules and then on April 28th, TSMC Solar, based in Taiwan, also announced a 16 percent CIGS efficiency level. The world record for solar power efficiency is currently held by Trina, at 20.8 percent.
Tesla’s Elon Musk believes that solar is going to go ballistic in the near future, becoming the world’s largest energy source by 2031. The available stats certainly seem to give cause for optimism. In the US in 2014, renewable energy only accounted for 13 percent of overall generation, of which solar contributed just 3 percent. However, according to the Solar Energy Industries Association (SEIA) it is the fastest growing source of energy generation in the US with almost 23 GW of installed capacity. This is predicted to double by the end of 2016. The SEIA report found that the third quarter of 2015 was the eighth consecutive quarter in which US PV installation grew by more than 1 GW. Throughout the first three quarters of the year, 30 percent of all new electric generating capacity brought online in the US was provided by solar. More than 50 percent of US states now have more than 50 MW of cumulative solar power.
Economically, solar is almost at the stage where it can be competitive with fossil fuels but it has a very bright future given that the sector has been consistently able to reduce the cost of solar panels. That is important given that, in the US at least, electricity prices will continue to rise while the cost of solar continues to fall. This is also true in the UK where there are worries of a shortage of electricity following numerous closures of conventional fossil fuel plants. Among the British public, wind and solar remain popular and it is likely that popularity will continue to increase. Figures published by the Department of Energy and Climate Change (DECC) show that there were almost 800,000 domestic solar power schemes registered under the Feed-in Tariff in January. According to the Solar Trade Association (STA) more than a million British homes generate energy from either solar PV or solar thermal panels or both. Overall, the amount of solar power in the UK has risen 66 percent over the past year to more than 9 GW, representing more than 860,000 installations. Large solar farms account for around half of that capacity (51 percent) while just over a quarter (26 percent) has been installed on private homes.
[Image source: Russ Ferriday, Flickr]
Looking globally, SolarPower Europe’s report Global Market Outlook for Solar Power 2015-2019 finds that the total volume of global solar power installations could rise to 540 GW within just five years, triple the figure (178 GW) currently installed. A recent study by researchers at Oxford University predicts that global solar power installation will reach 20 percent by 2027 from 1.5 percent today, largely driven by falling manufacturing costs. India and China are both helping to drive this momentum forward, India’s Prime Minister Modi having announced the formation of an international solar alliance at last year’s climate change conference in Paris and China expanding its solar activities with the construction of large scale solar farms in addition to solar panel production.
So, indeed, Elon Musk might be right when he talks about a solar explosion in the near future. However, according to senior modelling analyst at Thompson Reuters Point Carbon, Yan Qin, the main barrier to that happening at present is grid infrastructure, which was designed for regular fossil fuel generation rather than variable, distributed generation renewables. This means that those grids have to modified and adapted, but this is a very slow process. It means that in order to forge ahead, solar may have to rely on support from other renewable energy technologies providing more consistent supplies of power, in addition to energy storage and smart energy systems.
The future could be bright for solar, but it will need some help.