Proposer: UAF Institute of Northern Engineering, Ak. Center for Energy and Power
Benefit/Cost Ratio: Applicant N/A AEA 1.27
ISER: the problems and issues with this econ review and write up were only partially addressed.
The size and nature of the thermal resource at Pilgrim Hot Springs remains elusive despite earlier exploration. The 2007 AEA Pilgrim Feasibility report indicated contradictory evidence of a shallow saline resource and a deep, more diluted resource – but neither the heat source nor the water source of the circulating geothermal system has been identified.
This project, in conjunction with a $4.6 million two-year Federal DOE grant, proposes to implement advanced geothermal exploration techniques to pinpoint the upflow zone of the geothermal fluid and verify the location, depth to resource, and temperature through a new drilling program. The DOE grant is contingent upon UAF securing the appx. $1.7 million in funding requested with this application.
The exploratory innovations are of the type recently used at Akutan that have brought promising anomalies into focus for their drilling program. The upshot of these combined technologies is to make for a more efficient and decisive description of the complete circulating system. This information will produce the best assessment and form of commercial potential.
Additional data will be collected from existing exploratory wells after repair. But a new drilling program will be directed with the benefit of satellite and low-level thermal imaging, etc.
The application did not specify the commercial application envisioned because its purpose is only to implement the most comprehensive study of the resource possible.
Contribution to Lower the Cost of Energy:
The electrical power in Nome is almost exclusively diesel, and the wind farm constructed by Banner Wind (1kW capacity) has been shut down. The future of wind is unclear.
The feasibility report demonstrates adopting geothermal comes at a cost of losing the jacket-water heating system in the City of Nome.
Applicant presented none. The record of studies on Pilgrim Hot Springs contains several configurations possible. Recent developments in the applications of commercial refrigeration technology to electric power production suggest the most likely scenario.
First, larger models of UTC-type technology applied to Chena Hot Springs are being developed. But they will need additional engineering to fit the circumstances of the warmer, but still moderate temperature at Pilgrim Hot Springs.
Previous reports have suggested a 30 year useful life. A 20 year horizon was chosen here as per common analysis spreadsheet. Average load of 4kW was specified with a final cost of $102 million. Estimates of costs are at least $50-$60 million, but potentially well over $100 million.
There are a large number of potential cost inflators such as helicopter transport of drilling rigs, special foundations for buildings as with the powerhouse in Nome, delays from permitting, rig price premiums and/or lack of availability, and transmission costs.
There are two primary factors affecting economics. First, Chena Hot Springs demonstrates that commercial refrigeration technology can adapt well to a moderate geothermal resource in producing electricity. The importance of this adaptation is that it lowers costs considerably. We cannot know, until after exploration work is completed, whether such will be true at Pilgrim. The temperature is warmer and the sizes of units will be larger. The engineering will be different and there is some luck involved in borrowing from existing commercial refrigeration technology.
Secondarily, transmission cost estimates have high variation and no detailed cost work-up has been done to date. The most recent AEA Geothermal Cost Matrix estimate for roads was $15 million compared with what the explanatory notes imply is more like $24 million. But in the feasibility study estimates of $30 to $45 million were given. The B/C ratios above, medium to higher, but not the very highest costs are assumed.
This resource, if exploited at all, affords an opportunity for some immediate ancillary on-site development such as for vegetable production. The possibility of a larger resource means additional power can be added at lower cost. Extension of power to Teller, Brevig Mission, and as far as Kotzebue are possible.
Geothermal of course has tremendous promise for sustainability. The purpose of the study is to quantify what level of exploitation is sustainable.
Potential Public Benefits:
There are several beneficiaries from development of electrical power from Pilgrim Hot Springs. That includes the owner of the property, the owner/operator of the facility, and finally the power end-users to a degree depending on the Power Purchase Agreement conditions and terms between property owner and operators. To the extent it lowers power cost equalization payments, the state benefits financially.
-- January 9, 2010