A Newer and More Powerful Green Upgrade Calculator
10,000 users and counting: RMI’s free tool and API now have even more capabilities to help electrification programs and contractors confidently share dollar, energy, and carbon savings estimates.
Today, RMI released Version 2.0 of its Green Upgrade Calculator – a free, advanced tool that enables home contractors, residential energy program implementers, and policy advisors to more accurately estimate the cost, energy, and environmental benefits of clean residential technologies. This includes any combination of upgrades such as rooftop solar, battery storage, air- and ground-source heat pumps, weatherization, heat pump water heaters, induction cooktops, and electric vehicles.
Since Version 1.0’s release one year ago, more than 10,000 individuals have used the Green Upgrade Calculator, and multiple home upgrade programs and HVAC software sales companies are integrating the calculator’s API to deliver custom results within their own platforms.
The API filled an important gap in the marketplace by allowing us to deliver tailored upgrade reports to program participants, including incentives and cost savings estimates directly within our program platform.
Improvements in Version 2.0
Version 2.0 builds upon these successes with three key improvements that make the tool even more useful:
- Geothermal heat pumps are now an upgrade option
- Results include a new energy use impact section
- Results are more accurate with further refinement options
New upgrade option: Geothermal heat pumps
Geothermal (i.e., ground-source) (GSHPs) are around 400% to 500% more efficient than gas heating and roughly 50% to 100% more efficient than air-source heat pumps (ASHPs). As a result, they can significantly reduce both energy bills and carbon pollution.
A common question GSHP contractors or incentive programs receive from homeowners is: Will these bill savings pay back, and are ground-source heat pumps more cost-effective than air-source heat pumps?
With GSHPs now included in the calculator, contractors and program administrators can answer that question more confidently. For example, RMI used the calculator to model a home in Ithaca, New York, and found that GSHPs were the least-cost HVAC upgrade, around $10,000 less than a central AC and gas furnace — owing in good part to the large New York State GSHP incentives. These results will vary significantly across New York and the United States — in nearby Maryland, the same home would see the lowest costs by upgrading to an ASHP — so we recommend using the calculator to assess the best option for each specific home.
New result section: Energy impacts and usage estimates
In addition to cost and carbon pollution, Version 2.0 now includes an estimate of a home’s annual energy consumption by end use. This can be especially helpful for companies pairing rooftop solar with electrification upgrades, or for programs reporting energy savings in evaluation metrics.
For example, if the home above was curious about pairing rooftop solar with a GSHP, a contractor could use the calculator to estimate the annual electricity usage for the home after installing a GSHP (around 11,700 kWh per year). With that insight, they could recommend the most cost-effective rooftop solar system (around 8.5 kW) sized to offset most of the home’s annual electricity usage.
Even more accurate results with further refinement ability
Estimating the cost or carbon impact of a home upgrade often comes with the answer: “It depends.” And it truly does — on a wide range of factors. That’s why Version 2.0 of the Green Upgrade Calculator builds on Version 1.0’s 100+ optional inputs with even more ways to tailor results to specific homes and systems.
New features allow users to refine hybrid heat pump configurations to minimize costs and specify HVAC refrigerants and leakage rates to see carbon pollution impact.
For example, if the home above was interested in a hybrid heat pump, a contractor could now compare the operating costs of using a new air handler (around $1,450) versus leaving the furnace in place (around $1,600) with a 20 degrees F switchover temperature. They could also now quantify the environmental benefits of switching from R410a to R32 refrigerant in the heat pump (around 0.3 fewer tons of CO2e per year — equivalent to avoiding the consumption of over half a barrel of oil).
Lastly, with leveraging the newest data updated across all inputs in Version 2.0, users can trust the tool’s results to reflect today’s market and assess how effectively the selected upgrades can address rising energy costs.
Want to integrate the Green Upgrade Calculator into your own site to easily estimate the costs and benefits of smarter, cleaner, and more efficient home upgrade choices? Sign up for API access today to unlock the tool’s full potential.
