About Fresh.Energy
An independent guide to cutting household energy bills and switching to cleaner energy — with the maths shown.
Why we exist
Solar panels, heat pumps, home batteries and EV chargers are some of the biggest purchases a household makes, and they're usually sold, not explained. Quotes are hard to compare, savings claims are hard to check, and incentive rules change often. Fresh.Energy gives you independent numbers and plain-English answers first, so you can buy — or decide not to buy — with confidence.
What makes us different
- The maths is visible. Every calculator lists its assumptions, and you can change all of them.
- We don't install anything. We have no equipment to push and no favourite brand.
- We cover the trade-offs. If an upgrade doesn't pay back in your situation, we'll say so.
Calculator methodology
Our tools use transparent, widely used approaches:
- Solar: annual use is estimated from your bill and rate; output uses peak sun hours × 365 with a 20% allowance for real-world losses (inverter, wiring, temperature, soiling) — similar to the default losses in the US National Renewable Energy Laboratory's PVWatts model. Panels degrade 0.5% a year. Exported energy is credited at the percentage of retail you set.
- Heat pumps: useful heat = fuel used × energy content × existing equipment efficiency; the heat pump supplies the same heat at the seasonal COP you choose. Energy contents: natural gas 29.3 kWh/therm, heating oil ~40.6 kWh/gal, propane ~26.8 kWh/gal.
- Emissions: grid electricity defaults to about 0.37 kg CO₂ per kWh, close to the recent US average reported in EPA eGRID data; direct combustion factors follow published EPA/EIA emission coefficients. Your local grid may be cleaner or dirtier.
- EVs: charging losses of 10% are included; maintenance cost per mile defaults are conservative, editable estimates.
Results are estimates for planning, not quotes, engineering designs or financial advice.
Editorial policy
Guides are researched against primary sources — government energy agencies, national laboratories and utility regulators — and reviewed for accuracy before publishing. We date every guide and update when prices, technology or rules change. Advertisers and partners never see or approve editorial content in advance.
How we make money
Fresh.Energy is free for readers. We earn from display advertising served by Google AdSense, from installer partners who pay to receive quote requests that homeowners have explicitly agreed to share, from labelled sponsorships and from reader support. None of these affect calculator results or editorial conclusions. See our disclosures.
Corrections
Spotted an error or an out-of-date number? Tell us — we correct quickly and note significant changes on the page.
Last reviewed 2026-10-30.