Knowledge Base
Clean energy articles and guides
Practical articles covering solar panel costs, EV charging economics, battery storage ROI, and home energy savings. Each article links to a free calculator so you can run the numbers for your own situation.
Solar Energy
Best States for Solar in 2026: Ranked by ROI, Incentives, and Payback Period
Installing solar panels pays back 2x faster in Hawaii than in Louisiana — and we crunched 50-state data to show you exactly where solar delivers the...
Federal Solar Tax Credit 2026: Current Residential Credit Caveats
Understand the 2026 federal solar tax credit caveat, project-year eligibility, placed-in-service timing, and why RenewableCalc does not default 2026+ residential projects to a 30% federal credit.
How Many Solar Panels Do I Need?
Learn exactly how many solar panels your home needs. Step-by-step sizing formula with real examples for California, Texas, and New York households with different energy usage.
Solar Panel Cost Guide 2026
How much do solar panels cost in 2026? Complete breakdown by state, system size, financing option, Section 25D expiration (federal ITC ended Dec 31, 2025), and payback timeline.
Solar Payback Period: How Long Until Your Panels Pay for Themselves?
Calculate your solar payback period with real data. See how federal incentive caveat, electricity rates, and sun hours affect when your investment breaks even.
Solar Tax Credit 2026: What Changed and What Still Works
The residential solar tax credit (Section 25D) expired. Commercial ITC (Section 48E) still applies to leases and PPAs. Complete guide to navigating federal and state solar incentives in 2026.
Solar Panel Tilt Angle: What Angle Should Solar Panels Be Set At?
Find the optimal solar panel tilt angle for your location. Learn how tilt affects annual production, seasonal adjustments, and why latitude-based rules work for most US roofs.
Solar vs Wind: Which is Better for Your Home in 2026?
Home solar panels have dropped 70% in cost since 2010, but small residential wind turbines now cost less than $10,000 for a 5kW system. Which renewable...
Is Solar Worth It in 2026 Without the Federal Tax Credit?
The 30% federal residential solar credit expired — but solar can still save money in 2026. Compare scenarios with and without the credit, find which states still pencil out, and learn when solar no longer makes financial sense.
Wind Turbine vs Solar Panels: Which Renewable Energy is Right for You?
Compare wind turbines and solar panels for home energy: cost, efficiency, space requirements, maintenance, and real-world performance. Find the best option for your property.
Electric Vehicles
EV Charging vs Gas Cost: The Comparison That Actually Matters
Compare EV charging and gas costs using annual miles, home electricity rate, gas price, public charging share, incentives, insurance, and maintenance caveats.
Level 1 vs Level 2 EV Charger: What's the Difference?
Compare Level 1 and Level 2 EV chargers: charging speeds, costs, installation requirements, and which one is right for your electric vehicle. Real US data included.
Battery Storage
Battery Storage Payback Assumptions That Actually Matter
Understand home battery payback assumptions: usable capacity, cycle depth, round-trip efficiency, TOU rates, export credits, outage value, incentives, and battery lifespan.
Best States for Battery Storage in 2026: Ranked by Outage Protection and Savings
Home battery storage saves California homeowners an average of $1,200 per year on peak electricity costs, while also keeping the lights on during...
How to Choose the Right Battery Size for Your Home
Home battery sizing guide: match kWh capacity to your backup needs and daily usage. Compare Powerwall vs Enphase vs Franklin WH with real costs and payback estimates.
Home Energy
Appliance Energy Cost: Calculate What Actually Uses Power
Calculate appliance energy cost from watts, runtime, kWh, electricity rate, duty cycle, standby load, and replacement timing before buying upgrades for energy savings.
How Many kWh Does a House Use? US Average & Calculator
Find out how much electricity your home uses: US average kWh by state, monthly breakdown by appliance, and how to read your electric bill. Includes consumption calculator.
Electricity Bill Reduction Checklist Before You Buy Solar
Prioritize LED lighting, thermostat settings, air sealing, appliance upgrades, time-of-use plans, audits, solar, and batteries by cost, payback, and next calculator step.
General
Best States for Heat Pump Installation in 2026: Ranked by Savings and Climate Fit
Heat pumps cut heating and cooling costs by 40-60% on average, but they save twice as much in Massachusetts as in Florida. We analyzed 50-state data on...
How to Calculate Your Home Carbon Footprint
Calculate your household carbon footprint from electricity, natural gas, fuel oil, propane, and vehicle use. Learn which changes make the biggest emissions impact with real EPA data.
Geothermal Heat Pump Cost 2026: What Homeowners Need to Know
2026 geothermal heat pump cost breakdown: installed prices ($15,000-$40,000), operating savings vs gas/propane/oil, federal incentive status, and payback math by climate zone.
Do Heat Pumps Work in Cold Climates?
Modern cold-climate heat pump performance at low temperatures: capacity curves, HSPF ratings, backup heat strategy, and real savings in cold regions vs oil, propane, and gas.
How Much Does a Heat Pump Cost in 2026?
Complete 2026 heat pump cost breakdown by system type, capacity, and region. Installation, operating cost comparison, and payback vs gas, oil, and propane — with verified policy caveats.
Heat Pump vs Furnace: Which Saves More Money in 2026?
Heat pumps can cut your annual heating and cooling costs by 50% compared to a gas furnace, but the math flips depending on where you live and what you pay...
Heat Pump vs Gas Furnace: Which Is Cheaper to Run?
Side-by-side comparison of heat pump vs gas furnace operating costs. Fuel prices, efficiency, climate, and the honest math on when each wins — no sales pitch.