Typical battery maintenance includes adding water, cleaning, and checking connections. More difficult but even more important is setting up a charging regimen to work well. Batteries last longest if they are regularly recharged fully. The worst thing you can do for your battery bank is to discharge it and leave it in that state for days. Ideally, your battery bank should be fully recharged every few days—one way (RE) or another (fuel-fired generator).
A few off-grid systems are blessed with year-round hydro, or with a balance of resources (sun/wind and sun/hydro are common) that eliminate or radically reduce the need for a backup generator. And there are also users willing to reduce their usage when resources are not available, limiting the need for backup. But for most off-grid systems, a fuel-fired generator is a crucial part of the system. It’s also one of the weaker parts—a loud, dirty, inefficient, and costly way to make electricity. Best system design includes a modest backup generator that is used as little as possible.
If you’re determined to live off-grid, you need to figure out how to make it happen. A crucial decision is whether you will leave the system design and installation to the pros or do it yourself.
If DIY sounds like fun, you’ll need to get an education. Home Power articles, and classes, workshops, and more advanced training may be part of your learning process. And in the end, you’ll need to buy your equipment from someone. I recommend not buying from the cheapest online source, but finding a source (preferably local) that can also give you advice and support as you design and install your system. This will be worth the somewhat higher cost, since one or two bad buying or design choices can negate a “bargain” purchase.
Most modern RE systems are installed by experienced contractors. But bear in mind that nearly all solar contractors spend their time selling and installing batteryless on-grid systems. And many of them have zero experience with battery-based systems—avoid these companies, even if they are professional and want to help. Find an RE contractor with a history of designing and installing off-grid systems, or at least one who has experience with battery-based systems.
Take a hard look at your situation before you jump into the off-grid lifestyle. You may find that a grid-tied system will serve your motivations and goals best—at a lower cost and lower environmental impact. If you choose to be off-grid, get realistic, get educated, and get good help. And then enjoy your independence with renewable electricity!
For more details about the differences between on- and off-grid systems, see homepower.com/PV-Basics.
“Before You Go Off Grid” by Allan Sindelar • homepower.com/137.100
“PV Systems Simplified” by Justine Sanchez & Ian Woofenden • homepower.com/144.70
For more on load analysis, see “Analyzing Your Electrical Loads” by Ian Woofenden • homepower.com/156.104
“Off-Grid Appliances” by Ian Woofenden • homepower.com/140.106
For more on system design, see “Designing a Stand-Alone PV System” by Khanti Munro • homepower.com/136.78
“Getting Started with Renewable Energy” by Ian Woofenden with Chris LaForge • homepower.com/120.44
“Choosing the Best Batteries” by Chris LaForge • homepower.com/127.80
For more on generator selection and sizing, see “Engine Generator Basics” by Allan Sindelar • homepower.com/131.96
“Sizing a Generator for Your RE System” by Jim Goodnight • homepower.com/138.88
“DIY or Pro?” by Joe Schwartz, Ian Woofenden & Justine Sanchez • homepower.com/145.48
Check out our many off-grid system profiles at homepower.com/solar-electricity/project-profiles.