Easy DIY Solar Lighting

Image Gallery A 15-watt compact fluorescent produces as much light as a 60-watt conventional bulb while using a quarter of the energy. MATTHEW T. STALLBAUMER

Many people dream of solar-electric power for their homes, but can’t afford whole-house systems. Here’s an affordable, entry-level system with which you can have fun and get to know the basics of solar power. This setup, built with a small photovoltaic (PV) panel, one battery and low-power direct current (DC) lighting fixtures, can bring solar lighting into your home or remote locations. If you can turn a screwdriver, you can install it yourself.

This project can augment your existing 110-volt lighting circuits. It’s a great introduction to simple solar circuitry, it’s easy to build, and it produces useful light for several hours a day. Not only will it impress your friends and neighbors, but you’ll also enjoy the satisfaction of using clean, renewable energy.

In most home settings, it probably won’t save you money, but in other circumstances this system could save you a bundle. If you want lights in a cabin, garage, barn or garden shed that’s far from installed power lines, this project could be far less expensive than hiring professionals to extend standard power to the building.

Our friends at Gaiam Real Goods, the pioneering retailer of renewable energy products, helped us design the Mother Earth News Low-Voltage Solar Light System (see photo; click here or call (800) 919-2400 to order it as a kit). The key is its use of energy-efficient loads and low-voltage, DC components and circuitry. That combination keeps total power demand low and simplifies installation. Compact fluorescent light bulbs (CFLs) and light-emitting diodes (LEDs) are available in 12-volt DC forms, and they’re ideal components for a small, off-grid supplemental lighting system. You can easily build a system that will run, say, two or three CFLs for two hours each evening and an LED for five hours — all powered by a small battery charged by a small solar panel.

We spent about $760 on solar components and about $80 on other parts. For ideas on reducing costs, see “Ways to Save on a Solar Light Setup.”

Once installed, the system has no operating cost and needs little maintenance. The light bulbs are rated to operate for thousands of hours, so they will survive for years when lit for a few hours a day. Both kinds of bulbs cost more than regular incandescent bulbs, but prices are dropping, and they will save you money over the long term. Plus, with this system you won’t pay a penny for electricity. The PV panel in our kit is warranted to produce at least 80 percent of its rated output for 25 years. The battery has the shortest life of all the components; the type we used will typically last three to five years. (For specifications on components, see the Low-voltage Solar Light System.)