Wisconsin’s WPPI Energy recently concluded a Demonstration of Energy & Efficiency Developments-funded project that sought to provide its member utilities with a method for reducing heating costs in customers’ homes.
Following a review of the existing literature, project managers at WPPI found a lack of primary research investigating the energy savings associated with Line Voltage Smart Thermostats. A meta-analysis study by Bonneville Power Administration inferred potential energy savings associated with LVSTs by comparing existing data for electric line voltage thermostats against that for bimetallic thermostats, which is both the least efficient and the most widely available technology used for residential heating. The study estimated that line voltage thermostat implementation could lower heating costs by 13 percent compared to bimetallic thermostats.
A 2015 Energy Information Administration Residential Energy Consumption survey found that roughly 12% of households with income below $20,000 per year are primarily heated using built-in electric resistance heaters, as opposed to more efficient alternatives such as heat pumps. Conversely, only 2% of households earning more than $100,000 per year use electric heaters.
According to WPPI, “LVSTs offer a cost-effective solution to help ease the energy burden of residents using electric resistance heat.” This initiative saw 883 thermostats installed, with each resulting in an average savings of 614 kilowatts per year, or around $70 in annual energy savings.
With the combined funding from DEED, WPPI, and member utilities, customers paid $25 per smart thermostat, which included the cost of installing the LVST and recycling the old thermostat at a free recycler.
While the project proved successful, WPPI noted several obstacles to LVST implementation. Some customers did not possess the technological literacy required to determine whether an LVST was compatible with their system, and, in several cases, electricians arrived for an installation to find that the existing wiring was not sufficient for an LVST. In other instances, customers were simply not interested in engaging with the process.
WPPI highlighted other difficulties, including disparate installation costs across service areas; the need to coordinate with and educate different installers across each service territory; difficulty finding ENERGY STAR-certified thermostats, which hindered WPPI’s ability to obtain funding through Wisconsin’s Focus on Energy program; and, most notably, the onset of the COVID-19 pandemic, which significantly delayed progress on the physical installations.
Crucially, the collection of data for the project allowed WPPI to develop a tool to identify customers with electric resistance heating based on their electricity usage. The resulting Electric Heat Identification Tool is a Microsoft Excel workbook that can identify customers likely to be using electric heat based on electricity usage data.
This tool can be used to inform targeted marketing efforts for this or similar programs, such as heat pump installation. Moreover, because this project was partially funded by APPA’s DEED program, the tool is also now available to utilities across the country to identify customers using electric heat.
With this program concluded, WPPI plans to invest unused project funds in developing a more robust version of its Excel-based tool, which it will leverage in tandem with all of its 51 member utilities to target customers for promoting the use of heat pumps as a cost-effective and energy-efficient alternative to electric heating.
The project’s actual spend utilized $63,367.71 in DEED funding, $48,675 from WPPI and its members, and $22,075 from the utilities’ customers.
For more details on this project, see the DEED project library.
APPA’s DEED program funds research, pilot projects, and education to improve the operations and services of public power utilities, with particular emphasis placed on the scalability and transferability of projects for other utilities. For more information on the DEED program, to become a DEED member, or to apply for a DEED grant, see the APPA website.