Honest energy math
We build the calculators behind the big energy decisions: solar, EVs, heat pumps, home electrification, and off-grid power. The math is the same whether the answer is yes or no, and we say so when it is no. We never sell your data.
Solar payback
Live previewExample: an 8.5 kW system at the 30% federal credit and NREL national averages. Your inputs change everything.
Run your own numbersThe IRA-era incentives
$369B
In clean energy tax credits created by the Inflation Reduction Act. Most are available to homeowners through 2032.
7–12 yr
Typical solar payback period, though it varies significantly by state, electricity rate, and system size.
30%
Federal tax credit for residential solar installations, available through 2032.
The incentives are real. But so is the fine print. We help you do the math.
Run the numbersEnergy & Solar
The financial math behind solar, off-grid power, heat pumps, home electrification, and EVs. Every tool runs on an engine we built and test, not a sales script.
Model your system size, local electricity rates, and incentives to find your break-even year and 25-year return at your inputs.
Size the battery bank, solar array, charge controller, inverter, and fused wiring for an off-grid van from your real appliance loads.
Compare the full cost of a heat pump against a gas furnace across climate zone, fuel prices, and IRA incentives.
See the combined payback for every gas-to-electric upgrade, with IRA credit stacking, appliance by appliance.
Compare gas, hybrid, and electric over 5 to 10 years of real ownership cost, not just the sticker price.
Most energy calculators are built by someone who wants to sell you something. Solar installers use them to close sales; EV dealers build cost comparisons to move inventory. When a tool helps you buy gear we may earn a disclosed commission, but the math behind the number never changes because of it. We run the numbers on an engine we built and test, and show you what they say, including when solar doesn’t pay back in time or when keeping your gas car makes more financial sense.
Also here
The investing, debt, and savings fundamentals behind every big purchase. The same honest math, no advice.
Enter your numbers once for your FIRE date, debt-free date, net worth, savings rate, and the highest-impact scenario the math identifies. Everything recalculates as you type.