Electricity and storing energy by itself, sustainability aside, is a hot topic and headache for most sailboat owners and cruisers. Luckily, innovation and technological advancements provide the solutions, and nowadays even at pretty affordable prices. Are you all set and happy? If so skip and spare your time. If not, this might help you towards the true and only goal: power and more power (not physical or political, just boring old electrical power). Power to charge and keep your electronics going, especially your smartphone and drone, maybe fridge and most importantly your tablet so you can read our nonsense.

Your main issue will be energy storage, so get it right. If you can afford to – go lithium and you’ll never look back. If you are cheap like us – don’t and you will dream about it. If you go with lithium you might reduce your capacity slightly as you will be able to discharge them deeper and more often. If you go regular (floating/AGM or whatever else) like us cheapskates, you’ll go slightly overboard in the capacity, nice and heavy it will be! But the shallower the discharge, the longer the battery life – any battery specific graph will show you, same applies to lithium, but perhaps to a lesser degree.

Having figured out the storage comes the next headache: charging – by engine (that’s a must), by shore power (depending on your sailing style quite useful), by sun/wind/hydro (also a must) or generator(not a must) ) or perhaps by all of the above. Personally we have experienced that right after the engine dynamo (default) solar is unbeatable, every boat should have a solar panel – when a boat comes out of production, a solar array should be mounted already. We are very strongly opinionated on that (all our investments are in renewables 😉). But come on, it’s just too good and cheap not to have it.
We have a 190 watt panel in the back and a cheap 100 watt flexible panel on the sprayhood (under the boom and of questionable quality). While being in Denmark/Sweden it gives us enough power from March through November for 2 people (fridge, phones, tablets, laptops, pressurized water, e-toilet pump, lights, diesel heater and instruments) even on cloudy days, while having a 300amp (12v) AGM bank, impressive right? Ok sometimes you have to adjust, think ahead and charge your phone during the day, do dishes or shower during sunny hours and you can’t run the heating all night but that’s ok.
If you are impressed, consider that you can easily have larger capacity solar and better/larger (lithium) batteries providing you all the electricity you might ever need and for free, without emissions. And the best part? You can do it yourself – all you need is power of will and some time – and a good youtube tutorial.
What you need?
- Solarpanel (mono or poly crystalline -big debate there – we have mono).
- A mount (plenty of solutions available, you can also just tie it on to your spray hood if it is a flexible one).
- A charge controller (preferably MPPT).
- Some cables and patience .
Then you just connect it all to your batteries and voila – satisfaction* at the highest level. Things might get a bit more complicated if you have multiple battery banks and types, but you can always for simplicity have individual systems for both starter and consumer batteries, avoiding DC to DC chargers etc.
*Maybe it’s just myself (Leo), but seeing the sunny amps flowing into the batteries is so cool. I actually tend to gather all electronics during the most productive hours to charge them so nothing gets wasted – exiting life I have.
Cost: Well, as with most things that depends and there are no limits. But with roughly 100 euros for a decent/middleclass controller (MPPT 10-30 amps), 200 euro for a 150-200watt panel, some pocket money for the cables and you are set. The biggest issue is always the space and mounting. One solution is using side railing mounts, relatively cheap and adjustable. Another option is a frame in the back (arch) for mounting, pretty cool! But unless you are good in welding and metal work or a complete naïve lunatic like myself* it’s probably quite expensive, but still worthwhile. (Leo bought the pipes online and welded the thing together without previous practice, let’s say it works and looks ok from a distance, which is still impressive). Lastly, flexible panels offer many mounting options, while often being strong enough to step on.





Hope you are convinced to go solar by now, and if not here is another fact: solar charges even when it’s cloudy or raining, and on bad sun angles the efficiency is still quite good. Any other systems (wind, hydro) should in our opinion be added as complementary to solar and not the other way around.
Wind: Well it’s great if you have the space to install it, you are willing to compromise on some noise and vibration, and spend time on windy anchorages. Overall it is a great addition to solar as it also provides power at night, and thereby keep your discharges even lower. Keep in mind though that the apparent wind is often very low when sailing, while anchorages aim to provide shelter from the conditions.
Hydro: Not too sure, sounds great, especially on long sails where power is needed through the night, some sacrifice on speed, but definitely a great and proven way to keep your electronics going on long rough passages. Included in some electric propulsion systems!
We’ve properly already exhausted your attention span with all our ramblings on energy. Just make yourself happy and invest in a stable good energy grid for your precious sailboat. To summarize :
- Batteries. Lithium: expensive but long lasting, lighter with higher energy density and output, ideal for heavier loads, fast charging. Regular: Heavy, but cheapish. Try to have a bigger capacity (even heavier), make sure to keep the discharge cycles shallow in order to extend the battery life.
- Production. Solar is a must have, wind and hydro are great additions.
- Usage. Reduce consumption (what a tip), use LED lighting and energy efficient electronics, less is more :). Plan ahead (charge when the sun shines), obvious but hard to follow.
Tips & Tricks
- Power banks: self charging solar power banks of higher capacity can provide you cheap independent options to charge your electronics (phone, camera, tablet, etc).
- Portable solar panels, can provide an option, if a permanent installation is too hard or unnecessary, you might use it both for sailing and camping.
- Large portable power bank/inverter solutions, at least one brand builds those beasts, they can include huge capacities of lithium batteries with integrated inverters and often solar charge controllers. Sets can include portable solar panels: A complete generator like solution for boat, cabin, camping etc. Will provide you enough power for larger appliances and tools or simply enough power for your laptop to work all day, some sailors use them to fire their injection cooker on board, which is awesome.
Continue reading:
One thought on “Electricity and energy storage”