Solar & Heat Pump Resources
A curated hub of the best free tools for planning a solar or heat pump project — official government calculators and databases, our own free calculators and guides, and practical checklists. Everything you need to make an informed, no-pressure decision.
Official government tools
Free, authoritative tools straight from US agencies and national labs — the same sources behind our calculators.
NREL PVWatts Calculator External
Estimate the energy production of a solar system at your exact address.
Open →DSIRE Incentive Finder External
Search every state and utility incentive by your ZIP code.
Open →ENERGY STAR Product Finder External
Verify a heat pump, water heater or solar product's certification and efficiency.
Open →NEEP Cold Climate ASHP List External
Find heat pumps that perform in cold climates, with capacity at 5°F.
Open →IRS Form 5695 (Energy Credits) External
The form for claiming the 30% solar and heat pump credits on a 2025 return (installs completed by December 31, 2025).
Open →EPA eGRID Emissions Data External
Look up your regional grid's carbon intensity for emissions estimates.
Open →Our free calculators
Run your own numbers in under a minute — no sign-up, no email, full formulas shown.
All Calculators Hub
Every solar and heat pump calculator in one place.
Open →Solar Payback Calculator
When your panels pay for themselves.
Open →Solar Tax Credit Calculator
Did your install qualify? 2025 vs 2026.
Open →Heat Pump Cost Calculator
Installed cost with 2026 rebates (no federal credit).
Open →Heat Pump Savings Calculator
Annual savings vs your current heating.
Open →Is a Heat Pump Worth It?
A quick verdict for your home.
Open →Our guides & references
In-depth, source-cited explainers and reference pages to help you decide.
Solar & Heat Pump Guides
50 guides on incentives, costs, sizing, brands and more.
Open →Compare Solar by State
Side-by-side solar outlook for 26 states.
Open →Energy Glossary
Plain-English definitions of every term.
Open →Frequently Asked Questions
Straight answers on costs, the end of the credits, and rebates.
Open →Sources & References
The primary sources behind every number we publish.
Open →How to Get Solar Quotes
Get and compare quotes the smart way.
Open →Project checklists
The key steps and questions for a successful solar or heat pump project.
Roof suitability factors
Direction, pitch, shade, age and space — is your roof ready?
Open →Installer red flags
How to vet an installer and spot a scam.
Open →Permitting process
Permits, interconnection and timelines.
Open →Heat pump sizing
Get the BTU/tons right before you buy.
Open →Maintenance schedule
Keep your system efficient for its full life.
Open →Methodology
How we build our calculators and guides.
Open →