Wider use of electric heat pumps to heat buildings creates a larger market for renewable energy, but also brings challenges, which can be addressed through building insulation and weatherization, cold climate heat pumps, thermal energy storage systems and distribution networks with a higher voltage. report says.
Heating more buildings with electric heat pumps could create a larger market for renewable energy.
But while the use of heat pumps, in a practice known as building electrification, is “getting a lot of attention” in the utility sector, “there is little information available about what network planners should do about it today,” says Sean Morash , author of a report. of the Energy Systems Integration Group (ESIG) entitled “Grid planning for the electrification of buildings.”
Several technologies can support the transition, including building insulation and weatherization, heat pumps for cold climates, thermal energy storage systems and higher voltage distribution networks. The report also discusses network planning needs.
The technology solutions deserve attention because buildings in the US primarily use fossil fuels for space heating and the report says building energy consumption is “expected” to shift from fossil fuels to electricity in the coming decades, including in the Southeast and Northwest. where heating with electricity is already common.
As buildings electrify, areas that now have peak electricity demand in the summer could move toward peak demand in the winter.
The increased peak loads on network infrastructure can be seen “particularly at the distribution level,” said Debra Lew, executive director of ESIG. Still, improving the energy efficiency of buildings through insulation and weatherization “can help mitigate and even reverse the increase in peak demand, highlighting the need to take a holistic view.”
The report cites a study showing that approximately 40% of winter peak loads “were eliminated” when modeling the impact of energy efficiency and building enclosure upgrades on whole-home electrification scenarios in Pierre, South Dakota, a location which was selected because of the extreme cold. winter temperatures.
A prolonged cold spell “poses challenges” when most buildings are heated with heat pumps, especially if the heat pumps rely heavily on supplementary resistance heating, the report said. The use of cold climate heat pumps, which operate with greater efficiency in sub-zero temperatures, together with building energy efficiency, can help reduce the risk of cold temperatures.
The U.S. Department of Energy is administering a challenge on heat pump technology for cold-climate homes, with eight manufacturing partners passing the laboratory testing phase. DOE is now working with nearly 30 state, utility and other partners to encourage the adoption of heat pumps for cold climates.
Battery storage is “arguably” less important than energy efficiency because energy efficiency “has no duration limitations,” the report says. Programs supporting equitable access to energy efficiency upgrades “are a powerful tool,” and utilities should consider efficiency incentives and target them “to the most impactful upgrades.”
The National Renewable Energy Laboratory found in a 2021 study that average building energy consumption is reduced by about 60% would be the key to achieving the cheapest 100% renewable network with building electrification.
Thermal energy storage systems in buildings, which can use hot water or heated metal or brick, can help prevent supplemental resistive heating from being activated, and can charge based on signals from grid operators “days or weeks before an expected weather event.”
To prepare for building electrification, distribution companies can “consider larger equipment and increasing system voltage,” the report says, “rather than building more infrastructure with few energy transfer options, especially in areas where acquiring land for a new substation is a challenge.”
Noting that an increase in voltage rating, “from 4 kV to 12 kV for example,” is an expensive investment, the report says that “leading utilities have staged this investment and architectural shift by upgrading equipment as it requires replacement. or by providing all new construction with the improved voltage class. A similar strategy has been used for most network equipment, including service transformers.”
For grid planners, the report identifies four priority areas to improve distribution system planning: improving forecasts, holistically modernizing the planning approach, avoiding the biggest impacts by managing demand, and being proactive with grid upgrades.
ESIG’s Grid Planning for Building Electrification Task Force developed the report over the past year.
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