Guide
How Solar Payback Really Works
Payback is net installed cost divided by first-year bill savings. The 25-year picture adds panel degradation, rate escalation, inverter replacement, and loan cost.
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Worked examples for home energy costs.
Parameter tables plus hand calculations you can reproduce: bills, rates, solar, EV charging, commercial demand, and power factor.
Guide
What EV Charging Really Costs
Most EV cost confusion comes from mixing home rates with public fast-charger prices. Weight each by share of energy, add maintenance savings, and compare per mile.
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Time-of-Use Rates Without the Confusion
A time-of-use plan only wins when enough usage sits outside peak windows. Estimate peak and shoulder shares honestly before switching.
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Standby Power: Find and Kill Vampire Loads
Some devices draw power around the clock. A standby audit lists always-on loads, measures or estimates their watts, and ranks them by annual cost so you unplug or switch what matters.
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HVAC and Lighting Efficiency That Pays
Heating, cooling, and lighting dominate most bills. Thermostat setbacks and LED swaps cost little; use the calculators to rank hardware replacements after the free wins.
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Understanding US Electricity Rates
Four rate designs cover nearly every US bill. Match your tariff to the design, then use the matching calculator with shares that sum correctly.
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How to Read Your Electric Bill
An electric bill has four moving parts: metered usage in kWh, the energy rate, tier or time-of-use adjustments, and fixed fees. Learn where each lives on the bill before trusting any estimate.
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Which Appliances Cost the Most to Run
Multiply wattage by hours, adjust for duty cycle, and price at your rate. Water heating, space heating, dryers, and old refrigerators usually top the list.
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