Redmond staff review solar-plus-storage feasibility for four city facilities

City sustainability staff and a consulting firm told the Redmond City Council on April 8 that rooftop solar paired with battery storage could give several city facilities months of resilience during summer outages and reduce utility costs when the grid is operating.

Jenny Liebeck, Redmond’s sustainability manager, said the work was funded by a grant from the Washington Department of Commerce and was intended as a baseline feasibility study of four city facilities considered critical during emergencies. “One of our primary goals was really to come into this with a posture of learning,” Liebeck said. Ecotope consultant Mark Frankel walked the council through the technical assumptions and outcomes.

The study evaluated rooftop area limits and used daily generation/load profiles to test whether solar plus storage could run buildings in full operation, in a reduced emergency mode, or seasonally. For the Redmond Senior & Community Center, the analysis concluded that a roof‑mounted system sized with batteries could make most of the facility self‑sufficient from about March through October, and a small generator (about 50 kW, shown in the presentation as an example) could fill the winter shortfall to achieve year‑round resiliency.

Frankel explained the seasonal dynamics: “You’ll notice there’s two different yellow shades in this graph. That represents summer and winter generation…there’s a lot less sun in the winter.” He said the senior center’s energy profile and available roof area made it a promising near‑term candidate, while Fire Station 17’s shaded, small roof made it a poor candidate unless the station were rebuilt to modern high‑performance standards.

The presentation identified co‑benefits beyond resiliency: reducing peak demand with batteries could lower future demand charges, on‑site solar reduces grid carbon intensity, and daytime surplus energy could be directed to vehicle charging. Frankel noted that integrating batteries with smaller generators can be more efficient than relying on large generators that operate poorly at low load: “If you put in a big generator and then run at a really low load, you reduce its life span…incorporating a battery system that the battery meets the spikes and then having a much smaller generator…could be a much more efficient way to think about emergency power.”

Council members asked about campus approaches (sharing arrays/batteries among nearby buildings), noise and siting of battery systems near residents, and whether the report included specific design or cost estimates. Liebeck emphasized the study was high level: “you’re not gonna find specific design or cost estimates…we’re just trying to understand where our priorities are.” She said the next steps are mapping critical emergency loads for each facility, incorporating solar‑ready space into new construction (including the MOC project), and pursuing additional grants and budget funding for deeper analysis and potential pilot installations.

The study was prompted in part by an operational test during a recent “bomb cyclone” when the senior center served as a community hub and demonstrated its role in emergencies. Liebeck: “This became a hub for the community…so it became this natural place.” Frankel said that if the city pursues installations, early focus on the senior center and City Hall’s emergency operations center would make the most sense.

No formal action was taken at the study session. Staff said the city has budgeted funds in the current cycle for next‑phase work and will return with more detailed analysis and implementation recommendations as funding and grant opportunities allow.