Power on Namani
This is my report on how we generate and use electrical power on Namani:
1. Intro
Smell that melted charger! Look at that whirling wind genny! Hear those blades spin! These are some of the things that produce power on Namani. I'm going to write about how we get, use, deliver, and store power on Namani, our 35-foot boat. I chose this subject because on an isolated boat, away from power-plants and super-markets, we don't have tons of power and it's interesting to see what people use their limited power for.
2. Getting Power
A. Solar Energy
Solar energy is our most reliable source of energy on Namani because we are in a place with lots of sun. But there's always a but, and no way to get around these buts. The but(s) for solar energy are that it's not very efficient (about 20% of the sun energy hitting the panels gets turned into power), and that we only have reasonable sunlight about 6-hours-per-day, if we're lucky enough to have no clouds. But on a good day, we'll get a steady six amps for those valuable 6 hours, so I can't complain!
B. Wind Energy
Like solar energy, wind energy has a good side and a bad side. Wind energy is good in the sense that it's more efficient than solar energy (roughly 50% of the wind hitting the generator gets turned into power). This machine is also good because wind doesn't depend on the time. BUT generation still depends on a good, steady, breeze, which amounts to the same thing (unless you're on Cape Horn, which doesn't sound common to me). So this type of power generation isn't perfect, but there's no easy way to make infinite amounts of power on a boat, and Namani isn't built for nuclear fusion. Wind Power is the same as solar, though: with a good wind, we can run our fridge, plug in our PCs, watch a movie - life is good!
C. Tow Generator
We almost always use our tow generator on long passages when we are doing an OK speed. The generator works great on passages like this because it's rotation brings in a good steady amount of power and towing is quite efficient. The problem with towing the prop (nothing's perfect!) is that you need some sort of motion to make power, so it doesn't work at anchor and slows down the boat a bit when used. So if you could move the boat at a reasonable speed, we wouldn't need all those four solar panels, that big chunky wind generator, etc., but we can't do that, so we do need all those big things. So the towing is excellent on passage and we've had some very long ones, and I wouldn't throw this one out!
D. Marina plug-in
I'll keep this paragraph short, because we very rarely go to a marina. So that's one disadvantage. But it's good because plugging in is reliable, steady, and gets us more power than anything else. The trouble is (disadvantage 2) we almost never go to a marina and this is often expensive. The best thing about getting power this way (advantage 2) is that we run a power sander, our firidge, 3 laptops, everything off an AC / DC plug.
E. Running The Engine
If we start running the engine, we're in trouble with our batteries. As always, it has a good side: Motoring delivers almost as much power as plugging into a marina does and it's very reliable. So idling is great when we have loads of fuel. But this is bad for the obvious reasons: burns fuel and makes noise.
3. Use
A. Batteries
We keep all our power in our four 12-Volt batteries where we can use that power to run our refridgerator, etc.
B. 12V PLugs
Our special German engineer installed two 12-Volt cigarette plugs so we can charge our laptops, charge small batteries, etc. He also found something that turns one 12-Volt plug into two! Now we can have a maximum of three things plugged in at once. Pretty good!
C. What all those plugs and power are used for
All those plugs and power are used for most importantly, navigation. The computer (the great German Engineer turned it into a chart plotter), GPS, autopilot, navigation lights (tricolor and anchor light), radar (although we rarely use it), all these we use for Navigation. We only use these things underway but they are always at the top of the “important” list so we always save some power for these, especially on long passages. We also use our plugs and power for communications, including the computer (skype, email, airmail with Pactor Modem, etc), SSB radio (single sideband radio), and VHF radio (very high frequency). The SSB takes more power than the VHF but can send messages over hundreds of miles, while the VHF only has a maximum range of 10-20 miles. We use these three things in a broader range of scenarios but they come right after navigation on the important list. Probably the most useful pair is the computer and the SSB which we can use to send email, weather information, etc.
The third priority on Namani are household gadgets. Such as the refrigerator (although it takes 6.3 Amps!), indoor lights (LEDs), a fan, bilge pump, water pump. Now we are getting to things we don't need to have but are nice to have. For example, we could live on canned food instead of having a refrigerator but having one makes a much nicer lunch if you have fresh food. These aren't on the “important” list – more like the “nice” list!
The last and least important power category is entertainment. For example, Computers, Kindles (ebooks), MP3 player, cameras. We almost only use these at anchor and they are the least important power consumers on Namani. That means I can only use my computer if we have more than enough power for navigation, communication, and household gadgets. But they're still hard to live without!
4. Cconclusion
So we have quite a few power consumers on Namani but we can manage to get the power for them with a good windy day or a nice sunny one. But if we don't have sun or wind, we have empty batteries – then life is not so sweet! I think we wouldn't be able to do this is we didn'thave our wind generator or four solar panels, though.