Charging

Solar array

How many watts of panel does your day actually need? Pick your loads and your sun, and see which of the four linked packs gets you there.

Updates as you typeSame math as the original Megawatt tool

Your day

Live
Setup class
What runs each day
Peak sun hours
4.00 h

Want this for your exact ZIP? The solar by location tool pulls it from five years of real sun data.

Minimum array

75% system efficiency

Panel watts

0W

to break even each day

Daily load

0Wh

Sun hours

0h

Watts needed at each sun-hour levelYour sun hours

Packs that cover it

How the math works

Minimum array is daily Wh ÷ (sun hours × 0.75), rounded up. Each pack count is that number divided by the pack wattage, rounded up. The 0.75 covers heat, dust, wiring, and controller losses, and it’s the same figure the original Megawatt calculator used.

Keep planning

Solar plannerRoof layout, three build tiers, parts listsBattery bankDaily loads, days off-grid, and solar in. Voltage, amp-hours, and the Vatrer battery out.Solar by location and seasonZIP and panel watts in. Twelve months of real watt-hours out.Battery runtimeBattery size, usable share, and load in. Hours and a discharge curve out.