Fuel-Free, Emission-Free Power From Hot Springs
Hot Water Temperature: 110ºC
Flow Rate: 12 l/s
Net Power Output: 60 kWe
U.S. based ElectraTherm, successfully commissioned its Power+ Generator 4400 at an onsen site in Japan in April 2016. This is the first Power+ Generator in Japan, located in the city of Beppu, and it utilizes geothermal heat to generate fuel-free, emission-free electricity at the site.
The Power+ runs off low temperature geothermal steam from a small district heating system. As the Power+ generates power, it also provides cooling with zero environmental impact or imposition on the onsen’s primary function as a community resource. The power generated is sold to the local utility at an attractive feed-in-tariff rate for renewables.
ElectraTherm utilizes Organic Rankine Cycle (ORC) and proprietary technologies to generate up to 125 kWe of electricity from low temperature water ranging from 70-150°C. At this site, the onsen provides varying flows of geothermal steam at approximately 110°C. Unlike other renewable sources, geothermal heat is baseload, providing a continuous hot water flow with power generation capabilities 24/7. Hot geothermal water is the fuel used to create a high pressure vapor that expands through ElectraTherm’s patented twin screw power block, spinning an electric generator to produce clean electricity while simultaneously cooling the water up to 20°C.
“The US Department of Energy sponsored a program in 2012-2013 for ElectraTherm to develop a ‘micro-geothermal’ power plant that could tolerate remote, unmanned operation and also be able to handle the challenges presented by varying geothermal resources,” said John Fox, CEO of ElectraTherm. “This is the first commercial site in Japan to showcase that investment.”
“The Power+ Generator solves a problem at the onsen – cooling down water that is otherwise too hot, while also generating profit for the site,” said Yoshimaro Shimojo, Owner of BBA Consulting and project lead. “With Japan’s feed-in-tariff rate for geothermal at 40 Yen/kW ($.33/kW), we see a strong opportunity for profit at this onsen and approximately 40 other similar sites in the prefecture of Oita alone — and hundreds throughout Japan. The minimal impact to the property, the quiet sound profile, and the small footprint and distance from the public eye make this a virtually hidden gem for the site, serving as a resource and providing a fixed profit at an onsen that has been in operation for many years, and will continue for many more.”