Solar Siting Survey: Identifying vast potential for clean energy in southern San Mateo County

The first step to unlocking the commercial-scale solar market is assessing the technical potential for these projects within a specific geographic area.

Frank Wasko

Over the past few decades, the cost of solar photovoltaic (PV) panels has fallen precipitously while their efficiency has risen. Yet, a very small percentage of U.S. commercial sites have installed solar PV — revealing an untapped market.

Unlocking this important market offers a tremendous opportunity to expand cost-effective local renewable energy. Commercial-scale solar PV systems are significantly larger than residential systems, securing a lower installed cost per watt. And because these projects generate electricity close to where it is consumed, they don’t rely on transmission infrastructure, which is both inefficient and expensive.

The first step to unlocking this market is assessing the technical potential for commercial-scale solar development within a specific geographic area. As part of the Peninsula Advanced Energy Community (PAEC), an initiative designed to streamline policies and showcase projects that facilitate local renewables and other advanced energy solutions, the Clean Coalition conducted a Solar Siting Survey to assess the potential for commercial solar PV in southern San Mateo County. The PAEC Solar Siting Survey evaluated thousands of potential locations — based on site characteristics, existing loads, and grid infrastructure — to identify those that are best suited for a solar PV installation of at least 100 kilowatts (kW). In total, this Solar Siting Survey identified over 65 megawatts (MW) of technical potential for commercial solar installations within the PAEC region.

An overview of the PAEC area evaluated in the Solar Siting Survey | Source: Clean Coalition

Through our unique Solar Siting Survey methodology, we evaluate all prospective solar sites and then focus in on those sites that are most viable, given existing rooftop clutter, like piping and air conditioning units, as well as shading from trees and nearby buildings. While there are other online solar potential tools, the Solar Siting Survey approach provides far greater accuracy of technical siting potential and includes non-traditional structures for evaluation, including parking garages and surface lots.

Notably, parking garages and surface lots offer more than 40% of the commercial solar potential in southern San Mateo County. The Clean Coalition also identified numerous schools with attractive solar siting opportunities. While some schools had less than 100 kW of solar potential, when aggregated with other schools in their district, the 100 kW threshold was met. Overall, 448 potential commercial solar sites were discovered in southern San Mateo County, including 260 flat roofs, 49 sloped roofs, 111 parking lots, and 20 parking garages.

A closer view of the Solar Siting Survey | Source: Clean Coalition

The Clean Coalition’s PAEC Solar Siting Survey includes a comprehensive spreadsheet and a sophisticated mapping tool to support utility staff, city officials, solar project developers, and other community stakeholders in pursuing these siting opportunities.

If you are interested in learning more about the Clean Coalition’s Solar Siting Survey work, please contact Josh Valentine at

The Peninsula Advanced Energy Community (PAEC) is a groundbreaking initiative to streamline policies and showcase projects that facilitate local renewables and other advanced energy solutions like energy efficiency, energy storage, and electric vehicle charging infrastructure. PAEC will create pathways to cost-effective clean local energy and community resilience throughout San Mateo County and the City of Palo Alto; and beyond. PAEC is a collaboration between the Clean Coalition, the California Energy Commission, Pacific Gas and Electric, and an array of municipalities, emergency response jurisdictions, schools and universities, and corporate entities. For more information, please visit

Frank Wasko

Program Director

Frank brings to the Clean Coalition 30 years of service and experience from Southern California Edison (SCE) across a variety of functions, including field project management and field construction. In his last position at SCE, Frank served as Region Manager for government affairs. Frank also has a strong background in municipalization, infrastructure upgrade and improvement programs, rate optimization, and third-party interconnection.