Daylight no barrier to the rise of solar power

Sometimes you forget the extent of the impact that renewables have had over the last 10 years. It wasn’t until I received a press release today that spelled out the rapid increase in adoption in the US that I looked for data. The latest figures I could find showed 90,891 million kilowatt hours of solar thermal and photovoltaic (PV) power were generated in the US last year, a rise of over 26% year on year. This is from a beginning of only 493 million kilowatt hours in 2000, and that number had barely doubled by 2010. The lower half of the United States is an ideal environment for solar power with lots of unused land and lots of sun. The explosive growth has been helped by incentives, but now these may not even be necessary.

A recent report by Wood Mackenzie looks at the costs of the solar industry and has found that it is now the cheapest way to add electricity to many markets. The costs of extracting electricity from solar energy has continued to decline and the market is now self-sustainable in many areas. The research found that the solar market will continue to expand even without assistance from government subsidies and green initiatives. It estimated that the price of solar energy has dropped by around 90% over the last two decades and has the potential to drop by up to 25% further by the end of the decade.Those costs will continue to drop, mainly through advances in technology. The key ones highlighted in the report were the use of bifacial panels that allows the other side of the panel to generate up to 15% additional energy, larger modules that provide more surface area to collect power, and motorised systems that track the sun to allow the panels to face the correct direction to capture the maximum amount of energy. These, and other, technology advancements should ensure that solar power remains the cheapest possible way to generate energy well into the future. As Ravi Manghani, research director at Wood Mackenzie puts it, “Solar is becoming so competitive that not only is it a means of decarbonisation for corporate buyers, but also a way to lower the cost of energy for their businesses”.

It seems the only problem for solar looking forward is that half of the time we spent in the dark, but even that may not be as big a problem as it sounds thanks to researchers at UC Davis, who are pioneering ways of taking advantage of radiative cooling to generate electricity. The thermoradiative panels could capture the heat given off by objects as they cool and potentially generate a quarter of the electricity of solar panels, but during the night when solar panels can’t operate. The researchers are currently in the prototyping phase to see how practical examples stand up to the theory. The panels operate similarly to solar panels, but use different materials. If the two technologies can be combined, it will mean that the panels can operate around the clock.