Test of Time | Utah FORGE’s Longer Run Bears on FRVO’s Water Wall

Some commercial-scale enhanced geothermal system (EGS) developments rely on the assumption that reservoir water loss can be reduced to less than 1%. A new test in Utah could provide independent data on whether that level of performance is technically achievable. Fervo Energy’s (FRVO) planned 2 GW Cape Station development uses a sub-1% water-loss assumption to support development within its Milford Basin permit. The Utah Frontier Observatory for Research in Geothermal Energy (FORGE) began an extended circulation test this month at its injection-production well pair near Milford. The 90-day exercise, which could be extended to 120 days, will track “thermal breakthrough and water loss over time,” according to FORGE researchers.

Enverus Intelligence® Research (EIR) identified those issues as key technical considerations for Cape Station in its Water Wall report. The development must limit water loss to less than 1% to support 2 GW within its Milford Basin permit. No commercial enhanced geothermal system has demonstrated water loss below 1%. Fervo’s Project Red pilot, by comparison, reported water loss of about 30% over 614 operating days. Differences in reservoir geology, operating conditions and system design limit direct comparisons among projects. Still, the FORGE test could provide useful independent data on how water recovery changes during extended EGS operations.

Sage Geosystems added another data point this month after placing its 3 MW pressure-based geothermal facility near Christine, Texas, into service. The company said the facility, developed primarily for geothermal energy storage, recorded water loss below 10% across multiple operating cycles. That result was lower than the rate reported at Project Red but remained several times higher than Cape Station’s modeled target. Sage said the facility had operated for more than 120 days and that it is using the results to validate key elements of its broader approach.

EIR’s Priced for Perfection analysis also identified water loss as one of three unresolved technical considerations for Cape Station, calling the project “the real test of whether sub-1% is achievable in practice.” FORGE’s extended test could provide an early independent benchmark. Its results may help researchers and developers assess whether water recovery stabilizes during prolonged circulation and how closely experimental performance aligns with the assumptions underpinning commercial-scale EGS development.

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Top Three Takeaways:

1: Why is Utah FORGE testing water loss for enhanced geothermal systems?

Some commercial-scale EGS developments, including Fervo Energy’s Cape Station, assume reservoir water loss can be held below 1% to stay within their Milford Basin permit. FORGE’s 90-day extended circulation test, which could run to 120 days, is designed to independently track thermal breakthrough and water loss over time and provide data on whether that performance level is achievable.

2: What has Fervo’s Project Red pilot shown about water loss?

Project Red, Fervo’s pilot project, reported water loss of about 30% over 614 operating days, far above the sub-1% target modeled for Cape Station. EIR notes that differences in reservoir geology, operating conditions and system design limit direct comparisons between projects, but no commercial EGS has yet demonstrated water loss below 1%.

3: How did Sage Geosystems’ facility compare on water loss?

Sage Geosystems’ 3 MW pressure-based geothermal facility near Christine, Texas, recorded water loss below 10% across multiple operating cycles after more than 120 days in service. That result beat Project Red but still ran several times higher than Cape Station’s modeled sub-1% target, and Sage is using the data to validate its broader technical approach.