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Size your off-grid solar system

List what you need to power, set your battery and voltage, and pull real sun data for your land, then get panel, battery, inverter, and charge-controller sizing with a cost estimate. The same math an installer runs, free and in your browser.

Free for everyone
No account, no signup
Real NREL sun data
Made for off-grid living

Open the planner, it's free How it works ↓

The solar planner: a full-time homestead load list with a refrigerator, well pump, Starlink terminal, laptop, ceiling fans and LED lights, totalling 5.5 kWh a day, above a coverage bar showing a 4-panel array carrying that load on a worst-month day — A real plan in the planner: a full-time homestead running a fridge, well pump, Starlink and lights at 5.5 kWh a day, sized to a 4-panel array with the equipment estimate alongside.

Solar panels

count + total watts

Battery bank

amp-hours + units

Inverter

continuous watts

Charge controller

amps + MPPT/PWM

What it does

From "how many panels?" to a parts list.

Start from your real loads

Add appliances from a preset library of fridge, well pump, mini-split, Starlink, and power tools, or enter your own. Watts × hours × quantity rolls up into daily kWh and peak demand.

Real sun data, not guesses

Drop in your build location and the planner pulls month-by-month solar irradiance from NREL’s free PVWatts model, then sizes for the worst month so the system carries through winter.

Sizes the whole system

Panels, battery bank, inverter, and charge controller, sized together from your load, autonomy days, system voltage, and battery chemistry (LiFePO4, AGM, or lithium-ion).

Ballpark the cost

Matches your sizing to representative real-world gear so you get an itemized equipment estimate, a starting budget before you talk to an installer or order parts.

How it works

Three steps to a sized system.

List your loads

Add appliances from the preset library or enter your own. The planner totals your daily energy use and peak demand as you go.

Set system + location

Pick your system voltage, battery type, panel size, and days of autonomy. Add your build location to pull real NREL sun data for your area.

Read your sizing

Get panel, battery, inverter, and charge-controller sizing plus an itemized cost estimate, instantly, and saved in this browser for next time.

Why it's free

Built for off-grid living, not upsells.

River Ranch Hub makes free tools for people building a life off the grid. This planner runs entirely in your browser on free, public NREL solar data, with no quote forms, no email wall, no selling your info to installers. Use it to sanity-check a quote, plan a budget, or just figure out how much sun your land really gets.

Common questions

Off-grid solar, answered.

Yes. The River Ranch Hub solar planner is free and runs entirely in your browser, with no account, no email wall, and no quote form. It sizes panels, batteries, inverter, and charge controller from your appliance list and real sun data.

It depends on your daily energy use and how much sun your location gets. List your appliances and the planner totals your daily kWh, pulls month-by-month irradiance from NREL PVWatts for your build site, and sizes the array for the worst month so it carries through winter.

The planner sizes your battery bank from your daily load, your days of autonomy, your system voltage, and your battery chemistry (LiFePO4, AGM, or lithium-ion), and sizes the inverter from your peak simultaneous demand.

Yes. When you set your build location it pulls month-by-month solar irradiance from NREL's free PVWatts model, so the sizing reflects the sun your land actually gets rather than a national average.

Ready to size your system?

Free, no signup, and your inputs save right in this browser.

Open the planner

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Size your off-grid solar system