Retrofitting schools for zero net energy (USGBC Northern California) | U.S. Green Building Council
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Point Energy Innovations discusses how PG&E and other utilities show the feasibility of zero net energy schools in California.

In this series, speakers from USGBC Northern California’s GreenerBuilder conference, held July 13, 2017, at the Zero Net Energy Center in San Leandro, share insights from their sessions. Interested in supporting GreenerBuilder 2018 as an event sponsor or exhibitor? Please contact Brenden McEneaney.

Can schools lead the way to meeting California climate goals, doubling energy efficiency and reducing greenhouse gas emissions to 40 percent below 1990 levels by 2030? Can schools even go zero net energy (ZNE) today? Pacific Gas & Electric (PG&E) and other investor-owned utilities have launched ZNE schools pilot programs from 2015 to 2018 to demonstrate that it is not only feasible, but also practical and economical to retrofit schools to ZNE throughout California.

As noted by Peter Turnbull, PG&E has 12–14 pilot ZNE school retrofits under way, including one at San Francisco Unified School District (SFUSD), and is partnering with sustainable engineering experts such as Point Energy Innovations to develop deeply efficient, cost-effective and highly replicable pathways to ZNE.

Retrofits will typically reduce energy use 30–40 percent, achieving Energy Use Intensities (EUIs) under 20 kBtu per square foot per year. PG&E is advancing this knowledge through public training and outreach, and considering the program through bulk purchase opportunities for equipment such as tubular skylights, heat pumps and LED lamps.

This “straight-to-ZNE” strategy may be more critical than previously thought, as SFUSD’s Nik Kaestner pointed out by showing the dangers of using natural gas as a transition fuel.

Kaestner explained that schools are well suited to be ZNE leaders, with access to public funding, long-term benefit from energy cost savings due to owner-occupied buildings, good potential for renewables, and serving as beacons for learning about and demonstrating environmental stewardship.

With its own carbon reduction plan in place, SFUSD is using Prop 39 funding to slash energy use in existing buildings through such measures as LED lighting, better windows and insulation, heat pump domestic hot water systems and HVAC and controls retrofits. Importantly, SFUSD has committed to no new gas boilers, and is designing all new buildings to be ZNE immediately.

Alexis Karolides of Point Energy Innovations pointed out that the most important retrofit measures are those that enhance health and comfort, in addition to energy efficiency. Some of the measures enacted commonly across many schools involve reinstating health and comfort features originally designed but decommissioned, such as daylighting features. Reinstating the view glass daylighting and augmenting it with tubular skylights can enable lights-off learning and provide more productive environments connected to nature.

Another retrofit that provides health benefits is replacing noisy, inefficient heat pumps (commonly found in California’s many, formerly mandated, portable classrooms) with quiet, efficient new versions. Many teachers would leave the old, noisy units off so students could hear them teach, inadvertently causing discomfort and high CO2 levels in the classroom. New units provide both thermal comfort and the fresh air essential to optimal learning.

In summary, Nik Kaestner, Peter Turnbull and Alexis Karolides showed how ZNE school retrofit projects can uncover and correct dramatic inefficiency and discomfort issues, while leading the way toward meeting California’s climate goals and providing districts and taxpayers with significant lifecycle cost savings.

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