Client: WA Department of Commerce
Case Study: As a subcontractor to EES Consulting, Peak supported a cost-benefit analysis focused on new commercial buildings with a combined green roof and solar PV installation package (agrivoltaic). We examined the interaction of battery storage and its effect on the performance of buildings. The project team performed market research, outreach, 3D energy modeling, and solar resource analysis to determine the environmental and financial impacts of these types of buildings across Washington and what the market potential is for implementation.
Peak conducted research with utilities, government entities, agriculture professionals, and building owners to answer the question of the cost-effectiveness of combined green roof and solar PV installations. Our approach to the study of green roof and agrivoltaic costs and benefits combined knowledge from a deep bench of energy economists, building efficiency energy engineers, and agricultural and landscape architect experts from EES, a full-service civil engineering consulting firm.
The resulting work product included design and best practices, an updatable benefit-cost model, and program design recommendations/best practices. Secondary research into co-location looked at multiple studies and pilot projects already conducted on both components (green roofs and solar PV) together and separately. Finally, we surveyed green roof installers to obtain information on best practices and local costs. The resulting report to the Department of Commerce distilled information for future policy consideration.
Impact: The study showed that commercial rooftop agrivoltaics on new buildings had similar costs but varied benefits depending on climate zone, solar zone, and stormwater utility characteristics. This information will advise the Department of Commerce on policy impacts and the appropriateness of various incentive designs. This creative partnership allowed the project team to explore ways that solar and green roofs can fight climate change and mitigate stormwater impacts.
Green rooftops paired with agrivoltaics have the potential to solve multiple challenges in areas with high population growth such as Washington State. Western Washington in particular has seen significant growth in multifamily building investments. Urban planners must balance the trade-off between energy-efficient buildings, climate change readiness, and the need for urban green spaces. Agrivoltaics could provide relief for some of these impacts.