Council hears McKinstry study recommending hybrid electrification for City Hall, full electrification for maintenance center

Sammamish City staff and consultants from McKinstry presented a facilities electrification study for City Hall and the city’s Maintenance & Operations Center (MOC) during the June 2 council meeting, outlining technical options, costs and emissions outcomes.

Director of Parks and Recreation Anelie Mayer introduced the study and said it was intended to guide replacement of aging mechanical systems as they reach end of life without committing the city to immediate construction costs. Andrew Rody, the city’s facilities project manager, described a plan that coordinates equipment replacement with existing renewal schedules so the city can avoid replacing systems twice.

Sarah (McKinstry), the buildings performance engineer leading the analysis, summarized two scenarios for each building: full electrification and a hybrid strategy that relies primarily on high-efficiency heat pumps with limited gas backup sized for rare, extreme-cold peak days. For City Hall the consultants recommended the hybrid approach as the most cost-effective near-term path: their analysis showed roughly an 89% reduction in direct emissions under the hybrid option at about 58% of the capital cost of full electrification, while the full-electric approach would require substantial electrical-service upgrades and a replacement of the on-site diesel generator.

Mimi Peterson (McKinstry) discussed electrical service capacity, solar sizing and EV charging. City Hall was judged a good candidate for up to a 100 kW rooftop solar array (estimated annual output ~94,000 kWh) that could reduce electricity purchases and help offset demand charges; consultants noted the federal Inflation Reduction Act tax credit creates a narrow incentive window and urged early action on solar to capture it.

For the MOC, which has more standalone gas equipment, McKinstry recommended full electrification because conversions can be completed equipment-by-equipment and the existing electrical service can absorb the change without major upgrades. That option produced larger percentage energy reductions and avoided the costly second utility service that City Hall’s full-electric scenario would require.

Council members asked detailed technical and budget questions. Council Member Pam Stewart pressed whether the study’s energy assumptions were current and whether the city should request a social cost-of-carbon comparison; the consultants said they used current utility rates and that the social-cost calculation could be added. Council Member Train and others asked about microgrid/islanding and battery storage to address demand charges; staff said those options were outside the base study scope but could be considered in later design phases. Council Member Boyer questioned overall cost-effectiveness and emphasized the need to consider grid-supply trends and competing fiscal priorities.

City staff did not ask the council to appropriate construction funds at the meeting. Instead, council directed staff and the consultants to respond to follow-up questions, study a phased implementation approach that could be budgeted over multiple cycles, and return with more detailed cost estimates and grant/funding scenarios. Staff repeatedly flagged that the study’s findings are preliminary “road‑map” guidance and that subsequent design and procurement phases would be required before any construction appropriation.

What’s next: staff will provide additional analysis and a proposed phasing and financing plan, including potential grant and tax‑credit opportunities for solar, and return to council with budget-ready recommendations prior to any construction authorization.