Every watt-hour you do not use is a watt-hour you do not have to generate, store or pay for, which is why cutting demand is usually the first job in off-grid power planning.
Start with the audit
You cannot reduce what you have not measured. The book begins its energy chapter with an audit: list each device, its power in watts and its daily hours of use, then multiply to get watt-hours per day. The result shows which appliances dominate your total. Separate the essential loads (lighting, refrigeration, water pumping) from the optional ones, because the optional ones are where savings are easiest.
Habits the book recommends
- Use LED lighting throughout. Lighting is a small but constant load, and LEDs use far less than older bulbs.
- Choose energy-efficient appliances. A higher purchase price can be repaid by a smaller system.
- Cook with propane or wood fire rather than electricity, which takes a heavy load off the batteries.
- Do laundry on sunny days when the battery reserves are full.
- Dry clothes on a line instead of using an electric dryer.
- Heat water with a solar thermal system or propane, not an electric water heater.
Why this saves money as well as power
A lower daily total means a smaller array and a smaller battery bank for the same comfort. The book warns that careless use simply raises consumption, so good habits protect the system you have built. Matching heavy jobs, such as laundry or pumping, to the sunniest part of the day is a free way to make the same equipment go further.
Where to be careful
Propane and wood fires need proper ventilation and a safe installation. Do not trade lower electricity use for a carbon monoxide or fire risk, and follow the manufacturer's instructions and local rules for any fuel-burning appliance.
Once your loads are under control, planning the solar system becomes much simpler. For the wider picture, the Off-Grid Energy Systems guide and The Off-Grid Survival Manual cover the DIY side of power, water and daily systems.