Over the last several years we though about what we wanted in the boat and would it be practical to make it work. Basics of hot showers, plenty of water, plenty of free power. Most people go that is unrealistic. Well, not really. Today is one of those days i am very happy to have taken the time to plan out the most basic of needs, power.
As I write this, friends are slightly frozen in Tampa Bay (33), others are down right freezing in Virginia (12), and today its a balmy 59 here in Key West. But the real story will be next month when those power bills show up in the mail, and they go, WTF?
Solar and wind power on a sailboat is most likely the number one item that needs to be done right. I am watching my water maker running, the fridge kicked on, the onboard inverter running the sewing machine and all the while my charge controller happily blinking, showing 13.5 volts and in float mode showing full batteries! I cant tell you how many people said you really need to run the motor for an hour or two every day to top off your batteries.
Does this happen everyday? Mostly. For about a month with the lower output from the sun, it was every 3-4 days. As we move further into January its been every day. And no, i don’t have 20 panels laying all over the place. We installed 2 – 240 watt panels with a Blue Sky controller. And yes i have seen it consistently peak out between 25-29 amps solid. Todays total solar in was 122 amps. In January.
Match that with a wind generator and it has been a perfect match. At one point yesterday i saw 15 amps on wind and 23 amps on solar. At $0.00 repeatable cost. And yes, i know they cost to install, but ROI (return on investment) for us while in the marina was like 16 months. Now an hour of engine time is $4.00 a hr ( cost of diesel) or $1.08 an hr ( using Honda 2000 gen,gasoline fuel). So yes there is still a valid ROI even on the hook. In nearly 2 1/2 months off grid we figured ran engine 4 hrs and generator maybe 12-15 hrs max. Thats $32.20 for 80 days. Bite that Florida Power! And BTW the engine hours was mainly during some severe storms that blew threw ( running engine in case anchor broke loose) or we were running sewing machine/ Washing machine when inverter was down.
So take that time to look at your real power usage.
We are in the process of changing the house bank of batteries to a new set as these are greater than 5 yrs old and of questionable quality as they were used when we installed them. We are also increasing total amp hr capacity to around 850-1000 amp/hr of AGM.
Just for a reference to those trying to calculate their own usages, our max usage is around 8 amp/hr peak most days. But most times are less than 3-4 per hr as fridge runs less than 20 min per hr. That is lights, fridge/freezer, charging electronics and such. Add in our water maker draws 9 amps for 7-8 gal of water per hr. Yes we changed every bulb and fixture to LED years ago and still don’t regret any costs for doing that. Our typical day shows us running water maker from 1030-1630. Thats 6 hrs at 7+ gals of water-over 40 gals of usable water a day from solar.
And still things are running well.