Geothermal feasibility shows high school conversion possible but cost depends on tax credits and water handling

City staff presented a two-phase feasibility study showing a ground-source (geothermal) conversion could meet most of Northampton High School’s heating and cooling needs and fit within the school parking lot using inclined drilling, presenters said at the Sept. 9 Northampton Energy and Sustainability Commission meeting.

Ben (commission speaker) described the study’s central finding: ‘‘They found a way to make it fit,’’ meaning the proposed borehole field could be engineered into the parking area using inclined drilling. Consultant Brightcore evaluated loads, drilling techniques and system balance and concluded the borefield could satisfy roughly 90% of peak load while maintaining long-term thermal balance, the presenter said.

The study estimated a total project cost ‘‘something like $11,000,000,’’ according to the presentation. Presenters said federal tax incentives — described in the meeting as a roughly 30% investment tax credit (ITC) for large commercial geothermal — would apply and could reduce the net cost; with additional contentions about qualifying U.S. materials, presenters said another roughly 10% could be available. After incentives and credits, presenters stated the net project cost could be near $7,000,000 but cautioned that estimates depend on assumptions and the final financing structure.

A notable cost driver is produced-water handling from drilling. The study used a conservative assumption requiring off-site disposal, which the presenters said could add about $2,000,000 to the project; if on-site settling and DPW-managed disposal are approved, presenters said the cost could fall by roughly that amount. The consultants also flagged uncertainty that will only resolve once an initial well is drilled and the water chemistry and yields are known.

Financing options discussed included municipal bonds (taking advantage of the city’s strong bond rating) and an energy-services (ESCO) contract in which a private contractor would front capital and be repaid from energy savings. Staff also discussed claiming Mass Save incentives and a custom commercial incentive; presenters said the financing approach was not yet finalized.

Commission and staff discussion explored alternatives and risks. Eric Winkler asked whether a Proposition 2½ override would be required; presenters said that a vote likely would not be necessary but that borrowing appetite and financing terms would determine the next steps. Louis Hasbrook of the building department emphasized that a building-department presentation should translate technical details into practical permit and code information for the public and said departments could prepare materials explaining permitting complexity.

Staff also described alternatives to full geothermal: replacing chillers with modern air-source heat-pump chillers (reversible air-to-water units) or continuing with boilers and incremental electrification. Presenters said air-source heat-pump performance assumptions in the study may be conservative and that newer refrigerants and modulating units can raise efficiency. In the study’s life-cycle comparisons, presenters reported multiple scenarios; those numbers were discussed in the meeting (figures referenced included life-cycle estimates in the roughly $13 million–$19 million range depending on assumptions).

Presenters recommended further steps: seek clarification on produced-water handling with DPW, refine life-cycle cost details and financing options, and consider field visits to existing inclined-drilling sites. Several commissioners encouraged staff to ‘‘go hard on geothermal’’ if financing terms and incentives remain favorable.

This discussion was framed as preliminary direction and cost review; commissioners did not take a binding financial vote at the meeting.