Researchers at Soochow University in China have developed solar PV panels that can generate energy from raindrops, as well as from the sun. When the rain falls and rolls off the cell, the friction generates a static electricity charge. The static is enabled by two transparent layers of polymer that are placed on top of the solar PV cell. Although other similar devices have been created, this new technology has the advantage of being lighter weight. However, it is very much at the demonstration stage, and it could take three to five years until a prototype can be produced.
As solar PV technology improves and the costs fall, there has been a sharp increase in solar capacity over recent years. According to the BP Statistical Review of World Energy (2017), new installations totalling more than 75 GW in 2016 took global solar PV power generating capacity to 301 GW. Capacity had more than trebled over a four-year period. The largest increments in 2016 were recorded in China (34.5 GW) and the US (14.7 GW), together accounting for two-thirds of the growth in global solar capacity. Recent studies have predicted that solar costs will fall by a further 60% over the next ten years. However, these predictions could be somewhat tempered by more recent reports that the introduction of US steel tariffs could impact solar manufacturing costs. Large-scale systems that use more racks and mounts are expected to be the most affected. IHS Markit has predicted a 1 to 3 cent per watt increase as the result of steel tariffs. However, as it is early days for the new tariff regime, the effects are difficult to forecast.
Last year, the International Renewables Agency predicted that 80 to 90 GW of new solar capacity per annum would be installed globally. Australia is expecting a solar boom in 2018, having seen a record number of installation in February. Meanwhile, Tesla has started work on a solar rooftop at its gigafactory in Nevada where it plans to install 70MW of solar panels. In the UK, cuts to solar subsidies (2015) have slowed the rate of new installations. Capacity of solar PV increased by 72% in 2015 but stood at 25% in 2016. Solar capacity is expected to have grown by approximately 6% in 2017.