Answers, simply
One question per page, answered in the first two sentences. Tap in for more.
How much power do appliances use?
Electricity
- 112V vs 24V vs 48V: which solar voltage do you need?
Use 12V for vans and small rigs, 24V for mid-size RVs and small cabins if you prefer, and 48V for homes, tiny houses, cabins and most buses. Higher voltage moves the same power with less current, so wires are thinner, losses are lower, and batteries are simpler to scale.
- 2Can lithium solar batteries handle cold weather?
LiFePO4 batteries can power things in the cold, but they can't safely charge below freezing (32°F / 0°C). Keep them indoors or in an insulated space, or buy a model with built-in heating. Their built-in protection stops charging when it's too cold.
- 3Does solar work during a power outage?
Most grid-tied solar shuts off when the grid goes down. It's a safety rule, so power doesn't flow into lines workers are repairing. To keep power in an outage, you need batteries and an inverter that can run your home on its own (a hybrid or off-grid inverter).
- 4Everything you need to buy for an off-grid solar system
An off-grid solar system needs four main parts: panels to make power, a charge controller to move it into batteries, batteries to store it, and an inverter to turn it into normal outlets. At house size, the controller and inverter come in one box. Add wiring, fuses, a disconnect and mounting, and you're done.
- 5Fewer big solar panels or more small ones?
Same total watts, same power. Fewer big panels (400 W+) are usually cheaper per watt and far easier to mount, so they win for homes and cabins. Smaller panels only make sense when space is awkward, like a van roof.
- 6Home biogas digesters: cooking gas from scraps, not electricity
A home biodigester turns food scraps or manure into cooking gas: about 2 to 4 hours of burner time a day, if it stays warm. It doesn't make practical electricity at home scale. Think of it as a propane replacement for the stove, not a power source.
- 7How much does an off-grid solar system cost?
A weekend cabin runs about $5,500–7,000, a tiny house about $7,500–9,500, and a typical off-grid home about $13,500–17,000 in parts and wiring. Where you live matters: darker winters need more panels. After that, the power is free.
- 8How much electricity do you use? (The one number that sizes solar)
Find the month on your power bill with the most kilowatt-hours and divide by 30. That's your daily use. No bill? Add up your appliances: a fridge is about 1–2 kWh a day, lights and electronics a couple more, and anything that makes heat is the big one.
- 9Inverter vs inverter-charger: what's the difference?
An inverter turns battery power into normal wall outlets. An inverter-charger does that and can also charge your batteries from a generator or the grid. For off-grid homes and rigs, get one that charges: it's your backup for dark weeks.
- 10LiFePO4 vs lead-acid for solar: which battery should you buy?
LiFePO4. You can use nearly all of it (vs about half of lead-acid), it lasts thousands of cycles instead of hundreds, it's lighter and needs no maintenance. Lead-acid is cheaper up front but costs more over its life.
- 11MPPT vs PWM charge controllers: which do you need?
Get MPPT. It squeezes noticeably more power out of your panels, especially in cold weather or with limited roof space, and works with higher-voltage panel strings. PWM is only worth it for a tiny, cheap 12V setup.
- 12Micro-hydro power: is your creek worth more than solar?
If you have water running all year and some drop, yes, often. 10 gallons a minute falling 100 feet makes about 83 watts, day and night: about 2 kWh a day, enough for a fridge and lights, rain or shine. Watts ≈ drop (feet) × flow (gallons a minute) ÷ 12.
- 13Power station vs generator vs home solar for outages
A power station is quiet, safe indoors and perfect for keeping a fridge, lights and phones going. A generator runs big loads for as long as you have fuel, but it's loud and must stay outside. Home solar with batteries runs the whole house silently, every outage, with no fuel. Many people pair a small system with a generator for the darkest weeks.
- 14Ram pumps: move water uphill with no power at all
A ram pump uses a stream falling a few feet to push some of that water much higher, 24 hours a day, with no electricity or fuel. 12 gallons a minute falling 6 feet lifts about 2 gallons a minute up 20 feet: over 3,000 gallons a day. You need a year-round stream, about 5 feet of fall, and a place for the rest of the water to go back.
- 15Server-rack batteries, explained
A server-rack battery is a 48-volt lithium (LiFePO4) battery about the size of a suitcase that slides into a rack. It's the go-to for homes, cabins, tiny houses and bigger buses: about 5 kWh each, stackable, and made to last well over ten years.
- 16Small wind turbines for off-grid: worth it, or not?
Usually not. Rooftop turbines averaged about 214 Wh a day in a real-world trial: enough for phones and a few lights. A tower turbine can pay off if your yearly average wind is at least 9 mph and it stands 30 feet above anything within 300 feet. Otherwise, the same money in solar panels makes far more.
- 17Solar glossary: every term, in plain English
The words you'll run into when buying solar, each explained in one line: from kWh and inverters to MPPT, BMS and split phase.
- 18What are peak sun hours? (And why winter is the number that matters)
Peak sun hours are the number of hours per day of full-strength sun, the kind a panel is rated for. Most of the US gets 4–6 on an average day but only about 2–5 in the darkest month on tilted panels (NASA data), and about 40% less on a flat van roof. Size your solar for the darkest month.
- 19What is a solar array?
A solar array is simply all of your solar panels together. Ten 400-watt panels make a 4,000-watt (4 kW) array. The array's size, times your sun hours, is how much power you make in a day.
- 20What not to buy for off-grid solar (and why it's everywhere)
Skip lead-acid batteries for a new system, 'solar generators' as a whole-home solution, unbranded flexible panels, PWM controllers on big arrays, and grid-tie-only inverters if you want power in an outage. They're everywhere because they look cheap up front.
- 21What size solar panel do you need for a van or RV?
Most vans run 400–800 watts of panels (two to four 200 W panels) with 200–400Ah of 12V lithium. Big RVs and buses fit 1,000–2,000 W. Roof space is usually the limit, so plan to top up by driving or with a small generator in winter.
- 22Winter storm power outage prep: what you actually need
Keep four things running: heat, the fridge, lights and communication. If you heat with gas, back up the furnace fan (it needs electricity). A 2 kWh power station covers a fridge, lights and phones for about a day; a home battery system or generator covers heat and the rest.
- 23kW vs kWh: the only electricity lesson you need
kW (kilowatts) is how fast you use power, like how far a tap is open. kWh (kilowatt-hours) is how much you used in total, like gallons in a bucket. A 1,000-watt heater running for one hour uses 1 kWh, the number on your power bill.