About Us
About RenewableCalc
RenewableCalc provides free, accurate, standards-based calculators for solar energy, EV charging, battery storage, and home energy efficiency.
Independent estimates
No installer lead forms, paid placement, or quote brokering.
Visible assumptions
Rates, costs, incentives, and formulas are shown where they affect the result.
Reviewed data
Policy notes and benchmarks carry source context and update dates.
Why Trust RenewableCalc
RenewableCalc is a planning-grade tool for homeowners evaluating solar, battery storage, EV charging, and home energy efficiency investments. Every calculator displays its formulas, assumptions, and data-source context — nothing is hidden behind a black box.
- Visible formulas. Every estimate shows the calculation method and default parameters.
- Attributed data. Electricity rates, system costs, and incentive assumptions cite their source (EIA, NREL, IRS, DSIRE, EPA, ENERGY STAR).
- No data collection. All calculations run in the browser. We do not sell, license, or share user input.
- No paid placement. Results are independent of any installer, manufacturer, or utility.
Data Sources & Methodology
RenewableCalc aggregates public data from authoritative sources and applies transparent default assumptions. Key sources include:
- EIA— Residential electricity rates by state and month
- NREL PVWatts— Solar production context (insolation, tilt, azimuth)
- IRS— Federal Residential Clean Energy Credit (26 USC Section 25D)
- DSIRE / NC Clean Energy— State and local incentive programs
- EPA fueleconomy.gov— Vehicle efficiency ratings for EV vs gas comparisons
- ENERGY STAR— Appliance energy consumption benchmarks
- IEC 61724— PV system performance monitoring framework
- Lawrence Berkeley National Lab— Tracking the Sun installed-price benchmarks
Where state or utility-level data is unavailable, RenewableCalc uses regional averages and marks them clearly. Users can override any default with their own numbers.
Who This Is For
RenewableCalc serves three primary audiences:
- Homeowners— Evaluate solar, battery, EV, and efficiency investments before contacting installers
- Installers & energy professionals— Generate ballpark estimates and decision frameworks for client discussions
- Students & researchers— Explore renewable-energy economics through transparent, reproducible calculations
Limitations & Disclaimer
RenewableCalc outputs are planning estimates, not installer quotes, tax advice, utility tariff approvals, or financial guarantees. Actual system design, equipment pricing, financing terms, tax eligibility, utility interconnection, and local permitting requirements should be reviewed with qualified professionals.
Federal and state incentive rules change frequently. Users must verify current program eligibility, funding availability, and project-year requirements with the relevant agency or a licensed tax professional before making purchase decisions.
What We Offer
- Solar Panel Sizing— Determine how many solar panels your home needs based on roof area and electricity usage
- Solar ROI Calculator— Estimate payback period, net savings, and return on investment with visible assumptions
- EV Charging Cost— Compare electric vehicle charging costs against gasoline for your specific vehicle and driving habits
- Battery Storage— Size a home battery system and estimate backup value and payback
- Energy Consumption— Analyze appliance-level energy usage patterns
- Wind & Geothermal Sizing— Initial feasibility tools for wind turbine and geothermal heat pump projects
Updates & Maintenance
RenewableCalc data is reviewed and updated periodically. Electricity rates, system cost benchmarks, and incentive assumptions are refreshed at least quarterly. State-specific policy notes carry a “last updated” date so users can assess currency. Federal incentive rates are updated annually to reflect enacted legislation.
Contact & Feedback
Questions, corrections, or suggestions improve the accuracy of this tool for everyone. Reach us through the contact page.