My comments in the May issue on electric propulsion and fuel cells have spawned a surprising amount of interest. Not from owners wishing to go all electric drive but from owners wishing to embrace technology, enhance their electrical systems and eliminate the nightmare of half-flat batteries by using Fuel Cell and other types of technology.
We are used to throwing a switch at home and things just working, no need to think about power conservation or flattening the “Domestics”. Get on the boat all changes; most ladies want everything on the boat that they have at home and we chaps all agree with that. Just that as most of us are without a degree in Nuclear Energy, we struggle to maintain the amps to keep the hairdryers doing whatever they do, the microwave’s humming and the lights burning at night.
No problem if you are on shore support, all the amps come through the blue cable but get out at anchor or on a riverbank mooring or even an overloaded Marina power circuit and things subtly change. Without a Diesel generator or a battery bank from a milk float shackled up to an inverter, you may need to think of powering down stuff and getting out the Ray Mears survival books after a couple of nights away from shore support
It does not need to be like this, the days have gone when boating was about camping afloat and living out of tin cans, going to bed early to keep warm. Yes you can have lots of light and power, even your electric blanket in the winter. It can be done without running noisy smelly diesels on the mooring to charge the batteries Power Management and a balanced system is the answer.
More details can be found below.
Owning a boat is a unique experience unlike no other. The simple hedonistic pleasure of cruising along a River or Estuary (especially a tidal one and smelling the fresh salt on the flood), is for me like no like no other. Following close on this experience is either mooring or anchoring at my favourite spots and letting the world pass me by. I think most of us can get along for 24 hours or so without a care about “power”, but refrigerators, electric loo’s, T.V.’s etc and other power hungry bits of kit soon start to grind to a halt without a fresh charge in the batteries.
Some of my favourite mooring spots in Norfolk and Suffolk are so often spoilt by other owners and hirers seeking the same pleasures as I seek. So many beautiful afternoon and evenings are ruined by the knock, throb and stink of Diesel engines run off load just to charge Domestic batteries and heat hot water for showers. Even worse, the advent of very low cost petrol driven generators has brought instant power to everybody.. The other day I saw a small dinghy with an electric outboard going down the river with a small two-stroke generator howling away at 3000 rpm perched on a thwart charging the battery. All this technology in a 9’6” dinghy! I so hope this is not a vision of the future. At Bramerton Common a few days ago on a lovely Sunday afternoon we had two Hire Cruisers moored up, engines chugging away. A large Princess 41, the Generator valiantly struggling to power the air conditioning and keep the owners children comfortable whilst they watched a video. Whilst a little further along the bank a 27’ privately owned Broads Boat had a 3kw generator buzzing away on about 100’ of shore support cable. Nice one that, he moved the noise away from his mooring but spoilt the environment for others enjoying the Common. I gave up, left the boat and walked up to the pub to get away from the noise and mused about the problem.
Few of us today are purists, lighting our boats with candles and cooking with parafin. It was always so in my sailing days, the only electric gizmo we had was an electric bilge pump and the electric light in the loo. My battery would be lugged home about every third week for a charge. I loved every moment aboard as did my web footed daughter who even sounded like a character from Arthur Ransome when she was very young. To operate our brass Taylor paraffin cooker one needed a higher National Diploma in Steam Plant Management, asbestos fingers and the stamina to operate in confined spaces with searing heat. Often my dear wife would complain her hair was singed at the front from the wave of heat that came out of the oven when she opened the door. I, ever always, concerned for the welfare of the crew, gave her an old yachting cap cap to wear in the galley. A stoker from a steam train would have been quite at home it was terrific fun and even my dog loved the boat. Eventually my dearly beloved discovered all was not thus with the wives on other craft. Not everyone else had damp sleeping bags and guttering candles. Questions were asked about her health as her fingers were blackened from polishing with Brasso and blackleading with a tube of Zebrite ( Still have a tube or two somewhere although I am sure I would need to sign the poisons register to buy it today) neither did they need to go through their boats bent double, finishing up after a weekend afloat looking like Charles Laughton’s “Quasimodo” and perhaps even a permanent disability. The whiff of mutiny was on the air. The winds of change were howling through the boat so the yacht, hair shirts and all had to go to ensure I was not cast adrift in the dinghy with only my dog for crew..
It could be said that I then went from the sublime to the ridiculous. Our current boat is about as all electric as you can get, so much headroom a Texan complete with boots and stetson can walk everywhere. She must have every gadget known to man plus some from the Starship Enterprise that defeat even experienced children. However with thought and planning we can still go for several days at anchor or on a bankside mooring without needing shore support or running up the engines or the generators to charge batteries.
What we need to do is take a hard look at the options on offer to convert the many forms of energy into electrical power. It is not difficult to do but it does need an understanding of the problem and will require careful planning. You will need to invest in new equipment, as you may have guessed and you need to strike a balance between supply and demand. You cannot keep piling gear aboard even less installing inverters without ensuring the electricity will be available to power all the toys.
You need to make an assessment of what you think consumption will be. Consumption is usually expressed in watts (watts=amps x volts) You may prefer to use amps per hour (Ah), after all this is how we measure the battery capacity. We can if you wish make an assumption to illustrate the theory and assume the maximum we will use over a 24-hour period will be 100 Ah. That could be broken down something like as follows;
| Electrical Equipment | Power Rating (A) | Hours Used | Consumption (Ah) |
| Refrigerator | 5 | 12 | 60 |
| Cabin Lights (4) | 1 | 3 (each) | 12 |
| Stereo | 1 | 4 | 4 |
| Total Ah | 76 Ah |
Ok you may say, My Domestic battery is 100Ah so if I use 76Ah I will still have 24Ah left. This I am afraid is a frequent mistake and the reason Domestic’s fail so often and batteries often fail prematurely and need changing so frequently. A battery capable of sustaining a 10A discharge for 10 hours is stated to have a capacity of 100Ah. However this is where the issue gets more confusing because if you discharge a Lead Acid battery below 50% - 60% of its capacity you will very seriously damage its long term life. Also the other piece of information you need to know is that as its not always possible without some high tech regulating equipment aboard to charge said battery to 100% of its capacity. Accept that the power available from the battery will be somewhere around 30% of its rated capacity. So assuming you are able to be able to charge them every day it means you ought to have a capacity of at least 2.5 the daily demand or even 3 times to be comfortable.
Right, we now have satisfied ourselves we have sufficient reserves in our Domestic battery bank to sustain electrical power for 24 hours without killing the batteries dead. The challenge now is to replace the energy used without running the engines at the moorings which is a dreadfully expensive way to generate power and ruins a Diesel engine as they hate running on light loads. The easy way today is to fit a Fuel Cell, the mythical thing that will run our cars in the future. If you believe the soothsayers they will do away with overhead power lines as each dozen or so houses will have a Common Fuel Cell which will power the gizmo’s and heat the houses. Hmm, I will be happy to use one to charge my domestics for now. You can now fit a Fuel Cell that will silently give you 100Ah every day, just plug it in, give it a little drink of something and away it goes all without a degree in Nuclear Physics or even A levels. It’s a wonderful bit of kit, you are going to see a lot of them in the future but do destroy the on board video of Apollo 13 and do not ever mention NASA if you want to keep the wife aboard. Watch it in private again before throwing away because it was so good)
So you do not like cutting edge technology, fine we will look for another passive solution and we will consider Photovoltaics or Solar Panels. The most efficient (and expensive of course) are monocrystalline or polycrystalline silicone cells fitted together in series in an aluminium frame. There are other types perhaps Copper-indium-diselenide (CIS) panels are worth considering. They are a little less expensive than the others are and work better in marginal conditions which in our Northern Climes needs to be considered. I have a 50w panel mounted on the roof of my Camper Van and as I sit here typing this article my computer powered by the sun as is Classic FM on the radio. My panel will peak at about 3A and I can expect around 16amp hr. most days. Even winter sun produces about 1.5Ah something like 4 or 5 amp hr per day which is more than enough to keep the battery fully charged and power the alarm system. Four of these panels on my boat will just about make me independent of shore power, and with the Fuel Cell hooked in we are virtually independent of Engine or generator charging as well.
Of course you do not spend all you time tied up to a mooring you do occasionally start the engine and go somewhere so assuming your alternator is correctly matched to your battery capacity and you have a computerised regulator like an Adverc, Balmar, Driftgate or Sterling. You stand a fairly good chance of never having flat batteries again, with the added bonus that your batteries on a permanent floating charge; they will last for years and years. Your wife will love you because you will always have ice in the fridge for her gin and you are able to allow a quick burst of 240v on the inverter to power that 21st Century boating essential, the hair dryer (well I use it to heat seal the plastic ferrules onto mooring lines, what did you think I used it for!).
We can go much further with electrical self-sufficiency and look at wind generators. Lots of them on the market and believe me they are serious contenders. One of the beasts the American Air-X Marine will give about 28A in a mere 24 knots of wind. However, they do spoil the look of a boat, many of them make a noise, one or two a fearful din and all those rotating blades could be considered weapons of mass destruction with children about. But if you want serious power a combination of Solar and a Wind Turbine must be the answer.
If you want to enjoy the silence of a mooring, not disturb everybody running a generator and have some of the comforts of modern living do consider all the above. If you want help talk to us and as long as we can find the office calculator we can do the maths and recommend and fit a balanced system for you.