Boat & Motorhome owners wanting to either live ‘off grid’ or merely top up while plugged in, the main question is how much roof space have you got as well as storage! Having ‘home’ style panels really isn’t an option! If you have enough panels to actually net you enough sun then your roof space would be full! Add to this most house panels produce more watts than amps, then you start to see it’s an issue! Depending, of course, on what you require regarding energy consumed of a day this can be a real problem, especially for cruiser’s and motor homes with little surface area and narrow boats with minimum roof space, so how do you replace the amps used from your storage on an average day……..
The things to learn mainly are….
What you take out you must replace, it’s that simple! Most of us run through some form of inverter, switching a 1000w kettle on to boil takes 80A (while it’s boiling) these precious amps need to be replaced and as quickly as possible! Is that do-able? Well on a clear day the answer is YES, on a dull day it’s Hmmmm…..
So the thing to learn here is that summer is usually easy to recoup those lost amps, whereas winter is a whole new ball game, so going over the top on solar panels usually helps through the winter, however, I also needed more, due to the nature of the UK autumn and winter tending to be a little breezy, when the day’s got shorter I was looking for something else to charge my batteries. This is where wind turbines come in, i’ve spoke to lot’s of boater’s over the years and wind turbines are a sore point usually! What you have to remind yourself is what type of wind turbine they have tried, the little 907 Rutland type (very expensive) run on a whiff of wind but produce next to nothing, so pretty much useless! I tried a cheap 5 blade Chinese Ebay job, supposed to be 300w 25a 12v max, even in the strongest wind i only saw around 120w from this with around 10a at best, just to add…..a 5 blade turbine will actually spin up in less wind than a 3 blade turbine, however, it also slows the actual speed that it will achieve which is probably it’s downfall, although after stripping it to pieces it didn’t look like it would see more than a few years! So the search was on! The answer came in the form of a Turkish firm (Ista-Breeze) components that are German made (basically assembled in Turkey) I have used their i500 12v 500w for 3 years now and i have to say it still does the business! A little noisy in gail force wind’s but only as noisy as tree’s at the side of you, i’ve seen a constant 300w and 12a from this setup so for the price circa £250 it was worth it just to see me through those dark days!
On another note a lot of boaters seem to struggle with hot water. Again, from living off grid for so long, I needed a solution to this, preferably a free solution too! Moving to lithium batteries really opened my eyes however this solution is still easy enough to do on normal AGM/Lead Acid type batteries, the answer was a duel type immersion heater element, again lots of boater’s poo poo this idea, I have a 600w 12v element in a full size immersion tank, excess energy generated through summer from the solar panels merely trips a dump solenoid and heats the water, if you look inside of your average MPPT then you see it has a heater element on the rear usually, it should also have a large enough heat sink on the rear to get rid of the wasted heat generated by excess energy, so why not burn that energy somewhere else, the answer was hot water………works a treat!
As you can probably tell, i’m a believer in the fact that because we (as boaters) are limited on space then everything fitted should have more than one job! Prime example, no point in having a boatman stove on daily through winter and then paying for gas to cook on! Cook on the stove.
