Distributed waste heat to power generation service provider ElectraTherm sales and marketing director Kazunori Ueda in mid-April announced the commissioning of the Power+ Generator 4400 in Beppu, Japan.
ElectraTherm’s Power+ Genera-tors use waste heat on applications such as internal combustion engines, biomass boilers, incinerators, geothermal and also flare-to-power methane use at wastewater treatment plants and oil and gas fields. ElectraTherm’s Power+ fleet of 50-plus global installations have exceeded 520 000 hours of run time.
Ueda states that this is the first Power+ Generator in the country and the unit uses geothermal heat to generate fuel-free, emission-free electricity at the site. Commissioned in March, he says, the Power+ runs off low-temperature geothermal steam from a small district heating system. The power is sold to the local utility at an attractive feed-in-tariff rate for renewables. The existing geothermal well requires the temperature of the geothermal resource to be cooled before it can be used for heating. As the Power+ generates power, it also provides the necessary cooling with zero environmental impact or imposition on surroundings.
According to Ueda, the ElectraTherm unit uses Organic Rankine Cycle and proprietary technologies to generate up to 110 kWe of electricity from low-temperature water ranging from 77 °C to 122 °C. At this site, the hot spring provides geothermal steam at 110 °C.
Ueda explains that, unlike other renewable sources, geothermal heat is baseload, providing a constant and continuous hot water flow with power generation capabilities. Instead of expensive cooling equipment to lower the resource to a suitable temperature for heating, he continues, the water runs through the Power+ Generator which simultaneously cools the water up to 20 °C, while producing clean electricity.
“The Power+ Generator not only generates power and profit but also solves the problem of cooling water from the hot spring that is otherwise too hot for human use,” says Ueda, adding that “with Japan’s feed-in-tariff rate for geothermal at 40/kW (~$.33/kW), we see a strong opportunity for profit at this site and about 40 similar sites in the prefecture of Oita alone – and hundreds more at other districting heating systems and hot springs throughout Japan.”