Collection: Rich Solar

Sizing a Rich Solar system

Most off-grid disappointment comes from sizing to a panel wattage rather than to a daily energy budget. Work in this order and the components choose themselves.

1. Add up your daily watt-hours

List every load, multiply its wattage by the hours per day you run it, and total it. A 60 W fridge running 8 hours of compressor time is 480 Wh; four 10 W LED lights for 5 hours is 200 Wh. This total, not the peak draw, is what your system has to replace every day.

2. Size the array to that budget

A panel produces its rated wattage only in full, direct, perpendicular sun. Real-world output over a day is closer to 4–5 peak-sun-hours in good summer conditions and considerably less in winter or at higher latitudes. A rough planning figure: divide your daily watt-hours by 4 to get the array wattage you need in good conditions, then add margin for winter, cloud, shading and panel soiling.

3. Size the battery to your autonomy

Battery capacity decides how many days you can go without sun. Note the usable figure, not the nominal one — lithium (LiFePO4) banks can be discharged deeply and cycle far more times than lead-acid, which is why they cost more per amp-hour but usually less per usable cycle. Check the specification on each product page rather than assuming a chemistry.

4. Match the charge controller

An MPPT controller converts excess panel voltage into charging current instead of wasting it, and typically returns meaningfully more energy than a PWM controller from the same array — the gap widens in cold and in low light. The controller must be rated for both your array's voltage and its current, with headroom.

5. Add the inverter only if you need AC

DC loads — lights, fans, most RV appliances — run straight off the battery. An inverter is only needed for mains-voltage equipment, and it should be sized to your largest simultaneous AC load, with a pure sine wave output for anything with a motor or sensitive electronics.

Kit or components?

A complete kit removes the compatibility guesswork and is the right call for a first system or a standard RV or cabin setup. Building from components makes sense when you are expanding an existing array, working around an unusual roof, or matching an inverter or battery you already own. Every product page lists voltage, wattage, capacity and dimensions in full.

Frequently Asked Questions