solar systems
First, figure out your realistic amp hour draw per day. Factor in what you will generate from your alternator. Take the remainder, and multiply by four for your daily needs in watts. Be aware that this is a rough starting off place. Depending on time of year and geography, this can vary considerably.This does not assume that you will be constantly aligning your panels to get the best angle at the sun. Most people who try this just wind up chasing their tails, unless they are in a dock, or moored bow and stern, and can therefore predict the alignment of their boats. In the real world, you will most likely leave the panels alone. Try to figure out the most shade free areas to install panels. Some panels lose most of their power with just a little shade. Others, like some Seimens, BP, and Astropower panels, are wired so that you only lose less than half your power when somewhat shaded. The panels made by Uni-solar are wired so that the power loss is almost directly proportional to the area shaded, and can therefore be comparatively much more efficient than their specs would imply. Try to allow the panels as much ventilation as possible, and, if you are going to be in a warm climate, get panels with as high a potential voltage as possible,since voltage drops as panels get hotter. Make sure you have a large enough battery bank so that you use no more than a third of the capacity between charging cycles, ie. daily. This will also give you a higher rate of acceptance, when it comes to recharging them. Don't be reluctant to go bigger.....a bigger battery bank ALWAYS helps, in many big and little aspects of efficiency. If you are talking refrigeration, you will need enough panels and batteries to make voltage regulation essential. Next, get out your wallet or credit card. Undoubtedly, Solar power is by far the most expensive way to generate electricity. However, in my opinion, it is also by far the best way, offering a combination of reliability, simplicity, unobtrusiveness, environmental sensitivity, etc. It is the closest thing there is to a system you don't need to do much about, provided you have installed and sized it correctly from the outset. As for brands, I use a combination. This is based on about fourteen years of experience, much of it "off the grid" cruising, running a fairly electrical boat, equipped with DC refrigeration and water maker, among other things. I use Uni-solar panels in all areas that are subject to substantial shading. This includes the tops of the dodger and bimini and the cabin top (all of which can be shaded by the rigging and the mainsail and boom), and one other between the twin backstays. I use one very large 120 watt Astropower panel over the back of the cockpit, well aft of the backstays and protruding slightly aft of the stern. It slides forward and backward so that it either clears the windvane, or allows a view of the mainsail leach, depending on whether the boat is steering itself or a human is doing the honors. Altogether, the array consists of eight panels, with a total output of 324 watts. The Uni-solar triple film panels actually put out more per day than their rating would imply, due to several factors, so the equivalent, in "normal" panels would be about 350 watts. I have a new, rather obscure but potentially dynamite regulator, but have yet to install it and thus cannot offer an opinion. Be meticulous in your wiring, and make sure to fuse everything, since a short anywhere is equal to a dead short from the battery. Use oversized wire, so as not to loose voltage to resistance. Find a nice anchorage with lots of sunshine, and no boats running generators. Hoist a cool one, and enjoy. And, by the way, the guys at Solar Electric Inc, in San Diego, (www.solarelectricinc.com) are the best guys I have run into in this business. There is also an RV place just over the Arizona border from California (Quartzite?) that isn't too bad. Good luck.
