Combined geothermal heat and pressure retarded osmosis as a new green power system

• Published in: Energy conversion and management Vol. 226; p. 113504
• Main Authors: Madsen, Henrik T., Bruun Hansen, Thomas, Nakao, Takahito, Goda, Shohei, Søgaard, Erik G.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 15-12-2020; Elsevier Science Ltd
• Subjects: Clean energy; District heating; Draw solution; Electric power; Electric power systems; Electricity; Electricity generation; Geothermal power plants; Green energy; High pressure; LCOE; Mathematical analysis; Osmosis; Osmotic power; Osmotic pressure; Renewable energy; RO membrane; Salt domes; SaltPower; Salts; Turbines; Osmotic power; Draw solution; Electricity generation; LCOE; SaltPower; RO membrane
• ISSN: 0196-8904; 1879-2227
• DOI: 10.1016/j.enconman.2020.113504

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•Pilot plant as an osmotic power plant with high salimity water from geothermal wells.•Selection of suitable membrane for pressure retarded osmosis.•LCOE calculations for a combination of osmotic power unit with geothermal plant and as stand alone unit.
SaltPower is the name of a new renewable energy system. The system uses brine with high contents of salts to make an osmotic pressure that can become converted into electricity by help of turbines and generators. We present the principle of the energy system, the setup of a 20 kW pilot plant and laboratory investigations for the selection of a membrane that can resist the high pressure which can be up to 70 bar. The osmotic power system can be applied together with an already existing geothermal plant where hot water from the underground is used for district heating purposes. Alternatively, it could be applied where salt is extracted from salt domes and many other sources of salt.
Levelized Cost of Electricity (LCOE) is calculated on the osmotic power system when it is connected to a geothermal plant. The calculated value is competitive with other technologies creating electrical power.