U.S. Geothermal Inc. Provides Updates on Raft River Expansion and The El Ceibillo Development Project

• Increased generation achieved at Raft River
• U.S. Trade and Development Agency approves grant for the El Ceibillo Project

BOISE, Idaho, Sept. 27, 2017 -- U.S. Geothermal Inc. (the “Company”) (NYSE American:HTM), a leading and profitable renewable energy company focused on the development, production, and sale of electricity from geothermal energy, is pleased to provide an update on two of its projects.

Raft River, Idaho
The addition of a new production well (RRG-5) and an upgraded injection pump during 2017 have resulted in a total annual average increase of 1.6 net megawatts of generation at Raft River.  The upgraded injection pump was installed in August, after which the flow rate from RRG-5 was increased and additional flow from rebalancing the wellfield was realized.   This increased generation is captured under both our current power purchase agreement and REC contracts, and is expected to provide an estimated $1 million dollar increase in revenue for 2018.

Further improvements to the plant and wellfield are being analyzed and will be considered in the future.

El Ceibillo, Guatemala
U.S. Geothermal Guatemala S.A., a wholly owned subsidiary of U.S. Geothermal, Inc., has been awarded a $825,319 grant from the U. S. Trade and Development Agency (USTDA, https://www.ustda.gov/).  The grant provides funding for a feasibility study on the El Ceibillo Geothermal Power Plant Project, which will be led by POWER Engineers, Incorporated, headquartered in Hailey, Idaho.  The scope of the study is to update the resource evaluation, power plant design, financial analysis, environmental and regulatory review, and EPC technical specifications and bid package evaluations, in order to advance the Project to a construction-ready state.  We expect this study to begin within the next two months, with scheduled completion by the end of 2018.

Expenditures at El Ceibillo are being carefully controlled until we see evidence that the energy market is advancing in Guatemala.  The Guatemalan Government announced earlier this year that a Request For Proposals (RFP) for 420 megawatts of energy, which included 40 megawatts for geothermal, was going to be issued in 2017.  There is still no indication of when that RFP may be issued.

“We are pleased to report our progress on increasing generation at Raft River and in moving the El Ceibillo development project forward,” said Douglas Glaspey, Interim Chief Executive Officer. “Through the combination of increased generation from our current operations and planned new power plant construction, we remain focused on our goal of growing the company and enhancing shareholder value.”

About U.S. Geothermal Inc.:
U.S. Geothermal Inc. is a leading and profitable renewable energy company focused on the development, production and sale of electricity from geothermal energy. The Company is currently operating geothermal power projects at Neal Hot Springs, Oregon, San Emidio, Nevada and Raft River, Idaho for a total power generation of approximately 45 MWs. The Company is also developing an additional estimated 115 MWs of projects at: the Geysers, California; a second phase project at San Emidio, Nevada; at Crescent Valley, Nevada; and the El Ceibillo project located near Guatemala City, Guatemala.  U.S. Geothermal’s growth goal is to reach over 200 MWs of generation by 2022 through a combination of internal development and strategic acquisitions.

Please visit our Website at: http://www.usgeothermal.com

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.  Readers are cautioned to review the risk factors identified by the company in its filings with United States Securities and Exchange Commission.  All statements, other than statements of historical fact, included herein, without limitation, statements relating to the staffing of executive positions, development schedules or estimated resources of U.S. Geothermal, are forward-looking statements. Forward-looking statements are frequently, but not always, identified by words such as "expects", "anticipates", "believes", "intends", "estimates", "potential", "possible", and similar expressions, or statements that events, conditions, or results "will", "may", "could", or "should" occur or be achieved. These forward-looking statements may include statements regarding perceived merit of properties; interpretation of the results of well tests; project development; resource megawatt capacity; capital expenditures; timelines; strategic plans; or other statements that are not statements of fact. Forward-looking statements involve various risks and uncertainties. There can be no assurance that such statements will prove to be accurate, and actual results and future events could differ materially from those anticipated in such statements. Important factors that could cause actual results to differ materially from U.S. Geothermal's expectations include the uncertainties involving the availability of financing in the debt and capital markets; uncertainties involved in the interpretation of results of well tests; the need for cooperation of government agencies in the development and operation of properties; the need to obtain permits and governmental approvals; risks of construction; unexpected cost increases, which could include significant increases in estimated capital and operating costs; and other risks and uncertainties disclosed in U.S. Geothermal's Annual Report on Form 10-K for the year ended December 31, 2016 filed with the United States Securities and Exchange Commission and Canadian securities regulatory authorities and in other U.S. Geothermal reports and documents filed with applicable securities regulatory authorities from time to time. 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.

The NYSE American does not accept responsibility for the adequacy of this release.

FOR ADDITIONAL INFORMATION PLEASE CONTACT:
Scott Anderson – Director of Investor Relations and Corporate Communications
U.S. Geothermal Inc.
Tel:  208-424-1027
Fax: 208-424-1030
[email protected]