We started installing our components this week to make two of our boats more energy independent. While they still have engines that we use to get in and out of the harbor and drive the boat when there is no wind, we won't have to run them at all just to charge the batteries on a several day trip. If there is decent wind, we can often sail in and out of anchorages and sometimes even docks.
Now, I could go into an endless discussion about costs and benefits of what we are doing, but I'll just sum it up instead. We tried electric motors several years ago, but they are still too expensive and batteries are still not good enough for a long offshore trip. Rather than try to save the 20 gallons of diesel we use per boat every year,
Five years ago, we installed auxiliary electric motors on Dreamcatcher, which lasted only a couple months before they died. They were not designed for staying underwater
Since the wind is our main energy source, we only use about 20 gallons of diesel per year on each boat. I can save more fuel by riding my bike to work for a week, than to try to change the auxiliary power on the boats to electric. We tried an experiment five years ago and although it worked well, we decided to make the boats sail better and that would be more effective. Electric drives, powered by wind, solar and just turning the prop backwards when you sail, are available but still too expensive. Our objectives with this project are only to eliminate the need to run the engine for an hour every day to charge the batteries for our electric needs.
When you do the math, conservation is a lot cheaper than solar or wind generation and has a long term benefit. We use electricity for lights, VHF radio, radar, GPS, music system, fresh water pump and for charging electronics and cell phones. Air conditioning is only a matter of opening a hatch; heat, stove and oven are propane; there is no microwave and refrigeration is much more efficient by using ice from our ice maker in Bayfield. Radar is only used in fog, so it doesn't drain much most of the time. All the electronics are pretty efficient. That leaves lights and they are easy to replace with LEDs. Our new loads will be about 1/5 of what we used last year. That means the solar panels can be 1/5 the size.
We found some roll-up solar panels that can be attached on top of some of the canvas on the boat that protects us from the sun and spray. If the weather is bad, we can take them in. They will provide plenty of power for a several day trip without using the engine.
Most sailors motor in and out of the quiet anchorages so they can charge their batteries while making their maneuvering easier. I can only remember a couple people sailing in and only a couple sailing out of the anchorage, so when we do it, everyone watches with wonder. Running a diesel for short periods is not good for them, is noisy, and stinks, so we are looking forward to not having to do this. It is also great skills training for everyone and often draws applause from other boaters...
That reminds me of a story, which is much more fun than watts and amp-hours.