Cost-effective Advanced Window Retrofits for Schools
Electric Power Research Institute, Inc.
Recipient
Palo Alto, CA
Recipient Location
13th
Senate District
23rd
Assembly District
$33,871
Amount Spent
Active
Project Status
Project Update
In FY 2024-2025, project partners conducted site assessments and took measurements at the junior high and elementary school campuses selected by Bakersfield City School District to participate in the project. The project team installed measurement and verification (M&V) equipment to capture existing conditions at the school sites for one year, including HVAC-related energy usage and demand as well as window surface temperature and solar irradiance. Fabrication of the Wex SolarSkin product is now under way and is expected to be installed at the schools at the end of calendar year of 2025. Once the retrofit solution is installed, the project will conduct post-installation M&V.
The Issue
Windows are the most thermally porous component of the building envelope. Single-pane models are the worst offenders, and aging windows of all kinds can contribute to reduced building thermal performance. According to a 2013 PNNL report, approximately 40% of windows in the U.S. are single pane windows. Windows also are very expensive to upgrade or replace, especially relative to other building envelope improvements. On top of the high first cost, many old windows have lead paint on them and/or asbestos insulation in the walls, leading to higher cost of removal. Consequently, poorly performing windows are often left unaddressed, especially in low-income or disadvantaged households and communities.
Project Innovation
This project will demonstrate and evaluate the merits of an interior-mounted retrofit solution using WexEnergy’s WindowSkin product. The technology would reduce thermal energy loss from aging and underperforming windows, be minimally disruptive to building occupants and be cost-effective. The window retrofit technology acts as an interior window insulation panel that snaps on to each corner of a windowpane. The patented construction optimizes insulation by sealing and controlling the air gap between the inserted panel and windowpane.
Project Goals
Project Benefits
Windows are the largest source of envelope heat gains and losses. As such, improvements to window performance will lead to lower energy consumption through lower heating and cooling loads. From the occupant and operator’s perspective, the improvement in building energy efficiency will be reflected in lower energy bills. From the general perspective of the ratepayer, the decrease in cooling load, a driver of demand peaks in California, will bolster grid resilience, lowering the risk of negative grid events such as power outages and flex alerts. In the longer term, mitigating peaks in grid demand will also contribute to lower time-of-use rates, also benefiting California ratepayers. From an environmental perspective, mitigating peaks will lead to lower use of natural gas peaker plants, the state’s primary means of meeting spikes in power demand. Studies have shown that California peaker plants are frequently located in disadvantaged communities, so any improvement in air quality resulting from decreased peak usage would disproportionately benefit disadvantaged communities, further contributing to the State’s environmental justice goals.
Affordability
Improvements to window performance will lead to lower energy consumption through lower heating and cooling loads. From the occupant and operator’s perspective, the improvement in building energy efficiency will be reflected in lower energy bills.
Consumer Appeal
The technology implementation can also result in non-energy benefits, including reduced equipment sizing requirements, more comfortable and stable indoor temperatures and acoustic conditions for occupants.
Key Project Members
Agatha Kazdan
Doug Lindsey
Maggie Sheng
Subrecipients
CLEAResult Consulting Inc.
Intertek Testing Services NA Inc.
WexEnergy LLC
Sound Environment, Inc.
Match Partners
Electric Power Research Institute, Inc.
