Editing Hydropower (section)

==Rain power==

Billions of litres of rainwater can fall, which can generate huge amounts of electrical energy if used in the right way.<ref name = "IrishTimes">{{cite news |last= Nazarli |first= Amina |date= 16 June 2018 |title= 'If you can make energy from wind, why not from rain?' |url= https://www.irishtimes.com/news/environment/if-you-can-make-energy-from-wind-why-not-from-rain-1.3530666 |newspaper= The Irish Times  |access-date= 18 July 2021}}</ref> Research is being done into the different methods of generating power from rain, such as by using the energy in the impact of raindrops. This is in its very early stages, with new and emerging technologies being tested, prototyped and created. Such power has been called rain power.<ref name = guardian1>{{cite news |last= Carrington |first= Damian |date= 13 March 2018 |title= Rain or shine: new solar cell captures energy from raindrops |url= https://www.theguardian.com/environment/2018/mar/13/rain-or-shine-new-solar-cell-captures-energy-from-raindrops |work= The Guardian |access-date= 18 July 2021}}</ref><ref name = gadget>{{cite news |last= Fingas |first= Jon |date= 9 February 2020 |title= Rain may soon be an effective source of renewable energy |url= https://www.engadget.com/2020-02-09-raindrop-electricity-generator.html |work= Engadget |access-date= 18 July 2021}}</ref> One way in which this has been tried is by using hybrid solar panels called "all-weather solar panels" that can generate electricity from both the sun and the rain.<ref>{{cite web |url= https://www.euroscientist.com/scientists-design-new-solar-cells-to-capture-energy-from-rain/ |title= Scientists design new solar cells to capture energy from rain |last= Nichols |first= Megan |date= 21 May 2018 |website= EuroScientist |access-date= 19 July 2021 |archive-date= 9 April 2022 |archive-url= https://web.archive.org/web/20220409184913/https://www.euroscientist.com/scientists-design-new-solar-cells-to-capture-energy-from-rain/ |url-status= dead }}</ref>

According to zoologist and science and technology educator, Luis Villazon, a 2008 French study estimated that you could use [[piezoelectricity|piezoelectric]] devices, which generate power when they move, to extract 12 milliwatts from a raindrop.{{clarify|date=March 2025}}{{Fix|text=An individual raindrop is not a continuous process, so its electrical output must be measured in joules, not watts.}} Over a year, this would amount to less than 1 Wh per square metre – enough to power a remote sensor. Villazon suggested a better application would be to collect the water from fallen rain and use it to drive a turbine, with an estimated energy generation of 3&nbsp;kWh of energy per year for a 185 m<sup>2</sup> roof.<ref name = ScienceFocus>{{cite web |url= https://www.sciencefocus.com/planet-earth/is-it-possible-to-harness-the-power-of-falling-rain/ |title= Is it possible to harness the power of falling rain? |last= Villazon |first= Luis |website= BBC Science Focus |date= 28 April 2014 |access-date= 19 July 2021}}</ref> A microturbine-based system created by three students from the Technological University of Mexico has been used to generate electricity. The Pluvia system "uses the stream of rainwater runoff from houses' rooftop rain gutters to spin a microturbine in a cylindrical housing. Electricity generated by that turbine is used to charge 12-volt batteries."<ref>{{cite news |last= Coxworth |first= Ben |date= 26 March 2014 |title= Rainwater used to generate electricity |url= https://newatlas.com/pluvia-rainwater-microturbine/31379/ |work= New Atlas |access-date= 19 July 2021}}</ref>

The term rain power has also been applied to hydropower systems which include the process of capturing the rain.<ref name = IrishTimes/><ref name = ScienceFocus/>