Essential Electrical & Renewable Energy Calculation Tools
Electrical engineering and solar installation require precise calculations to size wiring, prevent voltage drops, and design reliable off-grid power systems.
Calculate daily, monthly, and annual operating costs for household appliances (AC, EV chargers, refrigerators) based on local utility tariffs.
Size solar panel array wattage, 400W panel counts, Lithium vs AGM battery bank capacities (Ah), and minimum inverter ratings.
Compute AC circuit reactance Xc, total impedance Z, and phase angle in degrees for audio filters and power factor correction.
How to Estimate Off-Grid Solar Power System Requirements
1. Calculate Daily Energy Consumption (kWh/day)
Sum up the daily watt-hours of all appliances you intend to power off-grid, including peak sun hour derating factors.
2. Determine Battery Bank Ah & Depth of Discharge (DoD)
Lithium (LiFePO4) batteries allow 80% Depth of Discharge, whereas AGM / Lead-Acid batteries should only be discharged to 50%.
Frequently Asked Questions (FAQ)
How do I calculate how much electricity an appliance uses?
Multiply appliance wattage by operating hours per day, divide by 1,000 to get daily kWh, then multiply by your local utility rate ($/kWh).
How many solar panels do I need to produce 12 kWh a day?
Assuming 4.5 peak sun hours per day, a 12 kWh/day requirement needs roughly a 3.1 kW solar array, which equals about eight 400W solar panels.
What is capacitive reactance (Xc)?
Capacitive reactance is the opposition offered to alternating current (AC) flow by a capacitor, calculated as Xc = 1 / (2πfC).
Why is voltage drop calculation important for wiring?
Excessive voltage drop across long wire runs causes motors to overheat, lights to flicker, and equipment to malfunction. NEC recommends under 3% drop.
Are my circuit calculations kept private?
Yes. All calculations occur 100% locally in your web browser. No circuit parameters or energy figures are ever sent to any server.