Michigan should consider combining community solar with the deployment of cold weather heat pumps in manufactured home retrofits, according to a paper by Lawrence Berkeley National Laboratory.
The paper, A Program Design Combining Community Solar and Weatherization for Manufactured Homes in Michigan, was developed by the Lawrence Berkeley lab in response to a request for technical assistance from the Department of Energy’s National Community Solar Partnership by the Michigan Department of Environment, Great Lakes, and Energy.
Home heating is the largest portion of residential energy expenditures in Michigan, especially for homes heated with propane and electric resistance heaters, and manufactured homes tend to rely on those higher-cost fuels, the paper’s authors noted.
In addition, incomes of manufactured home residents are generally much lower than that of residents of conventional housing, the paper said, noting that recent census data shows household incomes of mobile home or trailer residents in Michigan at $28,115, compared with $75,760 for residents of single-family detached homes.
To address those high heating costs, the paper’s authors recommended that the Michigan department should consider combining community solar subscriptions with the deployment of cold weather heat pumps in manufactured home retrofits, to replace electric resistance and propane heat as well as inefficient air conditioners. And to better manage the seasonal variation of heating bills and solar output, utilities may wish to implement a “solar banking” option or a seasonalized “budget billing” plan, the authors said.
There are many forms of community solar available to residents in mobile homes, the paper said, including systems maintained by a developer or utility, customer leased systems, and systems owned or leased by a community organization. How best to serve a manufactured home community may depend on how the homes are metered and where they are located, the authors added.
Weatherization of mobile homes presents steeper challenges, the paper’s authors said. They noted that American Council for an Energy Efficient Economy found that energy costs per square foot are roughly 50 percent higher in manufactured homes than in site-built, single-family homes and 20 percent higher than in apartments in large buildings.
However, there are several federal funding opportunities for manufactured homes, especially those occupied by low-income tenants or sited in disadvantaged communities, including a $4.3 billion Home Efficiency Rebates program and the $4.5 billion Home Electrification and Appliance Rebates program created by the Inflation Reduction Act.
Nonetheless, older manufactured homes, especially those dating from before 1994 energy standards took effect, may be good candidates for replacement rather than efficiency improvements and repairs, the paper’s authors said, citing an ACEEE report.
The authors noted that while the Lawrence Berkeley lab paper is not an exhaustive review of the issues, “it does briefly review some of the relevant facts and attempts to lay out a methodology for more in-depth analysis.” They also note that while the research is specific to Michigan, the recommendations and methodologies could serve as an example for other states and regions.
