U.S. Geothermal Provides Update

BOISE, IDAHO--(Marketwire - Dec. 20, 2012) - U.S. Geothermal Inc. (TSX:GTH)(NYSE MKT:HTM), a leading renewable energy company focused on the development, production and sale of electricity from geothermal energy, provides this update on its three operating projects.

Neal Hot Springs, Oregon

All three modules are operating and for the past three days have averaged 22.4 net megawatts per operating hour (31.5 gross megawatts). Module 1 has been in operation for 44 days, Module 2 has operated for 48 days and Module 3 with 8 days of operation. Under the terms of the PPA, November and December generation is paid at a seasonally adjusted price of $115.20 per megawatt-hour, which is 120 percent of the 2012 contract price.

The equipment supply contractor has stated its intention to commence required plant performance testing this week. The contractor has experienced certain project delays and is now under notice to complete the project within the required schedule. Project completion includes milestone activities related to testing and completion of a list of work items.

San Emidio, Nevada

Since performance testing was concluded in October, the San Emidio power plant has continued to operate on a normal basis. In November the plant averaged 9.42 net megawatts per operating hour (12.41 gross megawatts) and achieved 94.6 percent availability for the month. December operations were interrupted for 3 days due to the failure of an electrical component in a variable frequency drive. The plant has averaged 9.65 net megawatts per operating hour at 82.2 percent availability for December to date.

Work continues on finalizing a long term loan which is now anticipated to close in January. Remaining activities include finalizing the project lender's independent engineering reservoir and project reports, obtaining acceptable manufacturer/contractor support for certain turbine/gearbox vibration previously identified and addressed by the contractor, and completing final commercial settlement with the EPC contractor.

Raft River, Idaho

Raft River has operated continuously through the quarter with 99.5 percent operating availability and has averaged 9.61 megawatts per operating hour. The plant achieved 100 percent operating availability for both October and November. Due to warmer than normal fall and winter temperatures, power generation this year has been less than average.

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About U.S. Geothermal Inc.:

U.S. Geothermal Inc. is a leading renewable energy company focused on the development, production and sale of electricity from geothermal energy and is operating geothermal power projects at Raft River, Idaho, San Emidio, Nevada and Neal Hot Springs, Oregon. The company is developing El Ceibillo, an advanced stage, steam geothermal prospect located within a 24,710 acre (100sq km) energy rights concession area located 8.5 miles (14 km) from Guatemala City, the largest city in Central America.

The information provided in this news release may contain forward-looking statements within the definition of the Safe Harbor provisions of the US Private Securities Litigation Reform Act of 1995. These statements are based on U.S. Geothermal Inc.'s current expectations and beliefs and are subject to a number of risks and uncertainties that can cause actual results to differ materially from those described, including but not limited to, the successful settlement of issues with the EPC contractor and take out financing at San Emidio and the completion of Neal Hot Springs. Readers are cautioned to review the risk factors identified by the company in its filings with Canadian and US securities agencies. Forward-looking statements are based on management's expectations, beliefs and opinions on the date the statements are made. U.S. Geothermal Inc. assumes no obligation to update forward-looking statements if management's expectations, beliefs, or opinions, or other factors, should change.