Upgrade to energy independence Page 3
Step 4: Put It All Together
Once you’ve selected the major components, it’s time to put them together. You’ll need a monitor to keep track of the power going in and out of your battery bank and regulators to keep your power sources from overcharging your batteries. You’ll also need properly sized cables to connect everything, along with safety fuses and disconnect switches.
You may feel intimidated once this pile of equipment is gathered in front of you. Your first instinct may be to throw up your hands and ask a professional to install it. But with a little perseverance and patience, you can do it yourself. Just break the job down into several smaller projects.
We wired up our new batteries first. Then we installed a battery monitor, which told us if each new component was doing its job. When we hooked up the solar panel, for instance, the monitor showed a negative 4 amps rather than 4 amps coming in, so we knew something was amiss.
After mounting the panel, wiring it, and connecting the monitor/regulator, we moved on to the wind generator, which we treated as a separate project. We raised the windmill mast, attached the blades, ran the cables, and connected them to the battery bank.
Replacing the alternator involved installing larger cables to handle the increased amperage and installing an external regulator. Finally, we wired up the inverter.
Most projects took under a day. Before beginning each one, we read the instructions until we understood them fully, and we referred to other reference books if we had questions. Additionally, I had taken a basic U.S. Power Squadron marine-electronics class to gain more confidence. The same information can be gained from other resources.
Knowledge gained from previous electric projects involving homes or cars is helpful, but bear in mind that marine installations generally require a higher grade of wire to prevent corrosion. Tin-coated multi-strand copper wire is the standard. While soldering connections is common practice ashore, on a boat we use crimp connectors and put heat-shrink tubes over the connections to keep moisture out.
Remember, too, that there are safety issues. “Someone who clearly is not handy probably shouldn’t try working with electricity,” Hamilton Ferris warns. “Safe wiring practices must be followed so people don’t get hurt or killed. System reliability comes down to quality of installation. People can do their own work if they read the right books. But you have to understand things like proper wiring gauges and connections. When you’re going through an inverter and stepping up to 110-volt AC power, there is a serious shock risk.”
Designing and installing a DC power system is only part of achieving energy independence. Energy efficiency and conservation greatly affect the amount of power required on a boat. A 17-watt fluorescent bulb provides as much light as a 60-watt incandescent bulb and draws a fourth as much power. Better still, new LED lights use just a fraction of that amount. Similarly, it is important to turn off lights, instruments, and other appliances when not in use.
Also, certain high-draw appliances should not be run off DC batteries. Electric cooking appliances (like our toaster) require far more energy than most inverters and battery banks can reasonably produce. The same goes for hot-water heaters, home heaters, and air conditioners.
Aboard Sea Spell, we cook with propane and rely on the breeze, awnings, good ventilation, and fans to keep us cool. We added extra insulation to our refrigerator to reduce its power demand. We also added insulation above the headliner to help keep the cabin cool in the summer and warm in the winter.
The reward for our efforts is the ability to enjoy modern electric appliances wherever our boat is located. Two years after completing our upgrade, we know the effort and expense was worth it when we anchor in a remote cove, sip icy-cold cocktails as the sun goes down, and then step down into the cabin and turn on the lights.
It is helpful to understand a few basic concepts when working with electricity. Many excellent books have been written on the subject. A few of them are:
The 12-Volt Doctor’s Practical Handbook by Edgar J. Beyn, Weems and Plath
Independent Energy Guide by Kevin Jeffrey, Avalon House
12-Volt Bible for Boats by Miner Brotherton, Seven Seas Press
Boatowner’s Mechanical and Electrical Manual by Nigel Calder, International Marine
Sailboat Electrics Simplified by Don Casey, International Marine