RenCalc

What is RenCalc?

A free, browser-based set of home-energy planning calculators written for homeowners rather than for design firms. The tools cover solar panel sizing, solar return on investment, home battery storage, EV charging cost, household energy consumption and a federal and state incentives guide. A solar quote review tool compares an installer's cost per watt against state and national benchmarks without uploading the quote. Each calculator shows its formula and names its data source, which the site lists as EIA electricity rates, NREL PVWatts, IRS guidance, DSIRE, EPA fueleconomy.gov, ENERGY STAR and Lawrence Berkeley National Lab pricing benchmarks. No registration is required.

Record written 2026-10-07 from the vendor's submission and site. The site also goes by RenewableCalc in its own copy. The same submitter listed HVAC Calculator Pro on the same date.

Key strengths

• Six calculators covering solar panel sizing, solar ROI, battery storage, EV charging cost, household energy consumption and a tax credit and incentives guide
• a solar quote review tool benchmarks an installer's cost per watt against state and national averages without a PDF upload or account
• formulas are visible on each calculator and the data sources are named, including EIA rates, NREL PVWatts production data, IRS credit guidance and the DSIRE incentive database
• US state-level inputs for electricity rates and incentives

Common use cases

Limitations to know

The site is written for homeowners deciding on a residential solar, battery or EV charger purchase, not for firms sizing commercial systems or producing design documents. The vendor states that outputs are planning estimates, not installer quotes, tax advice, utility tariff approvals, engineering designs or financial guarantees, and that calculations are for reference only and a certified professional should be consulted for actual system design. The vendor also notes that federal and state incentive rules change often, so credit eligibility shown by the tools needs checking with a tax professional. Benchmarks and incentive data are US only. No company background, country or team is published. AEC Hub has not tested the product.