So, power, electricity, heat etc. All pretty much a must for the modern home and a topic of much debate amongst engineers, policy makers, politicians etc as regards the national infrastructure for grid requirements etc. There has been talk of rolling "brown outs" once the UK loses its coal fired power stations (although to be honest a "brown out" would seem to be the effect of a bad curry, but hey, who am I to change such terminology). What to do about it? Place your faith in energy companies and politicians to make the right choices and invest in... hahahahahaha...AAAAAAHHHHAHAHAHAHAHAHA... sorry. Like that's ever going to happen. You are on your own so you better have a plan. And I do. Which is lucky...

First of all there are a couple of compromises I have had to make to the world of hydrocarbons. The engine will still be diesel powered. I don't fancy propelling 130 tonnes of steel with solar panels, and we have sails to ensure we can use free energy to propel us when possible. I will also be looking at the suitability of biodiesel for the future but need to make sure it is going to be safe to use in a 'classic' engine like the 2H3. We will also be using gas to power our oven and hob (no doubt more on this - it was technically possible to do it otherwise but difficult). Our experience on our previous barge was that we would use one 13kg gas cylinder per quarter, so at about £25 a pop it's not that expensive and should a better solution arise it will be relatively simple to remove the gas lines.

Anyway, the plan is to be self reliant for as much as possible and to reduce our carbon footprint, insulate ourselves from any spikes in diesel/electricity prices but also to allow ourselves to be free from the restriction of having to moor in marinas with all the facilities (hence the inclusion of a aerobic sewage treatment system).

A schematic below shows the approximate setup:

You may chuckle at the inclusion of a wind turbine, but this was an addition for winter power production when solar insolation is lower and wind is increased. It means it will work overnight to top up the batteries and power the continual drain items such as the sewage system (0.6kWh), fridge freezer (circa 0.8-1kWh) etc. I have chosen 1kW as a manageable size for the turbine. It is about a 1.8m diameter generating surface for this output and 24V will generate more power than the 12V systems for a given wind speed. I am hoping to mount it at the top of the mizzen mast. At roughly 19m up it should get a welcome increase in wind speed, upping the power production.

The battery bank has been placed specifically as a store for the electrical power rather than as an accumulator which is constantly being charged and drawn down at the same time. This should lessen any loading on the battery bank and extend its life. If we are generating electricity and using it at the same time, I want the system to power our electrical loads directly from the distribution board not having to go through a battery, then out to an inverter and distribution board. The battery will be able to soak up excess electrical power but also provide a kick when power production is not met by demand.

On the subject of batteries I have decided, given the advice received, that Aqueon Saltwater batteries are probably going to be the best option. Although they are expensive (circa £1000 for each 2.2 kWh 48V stack) they can be fully discharged to 0% and then recharged without any damage. They are environmentally friendly with no corrosive acids and do not offgas hydrogen meaning easier installation, need no maintenance, no thermal management and with high cycle life and wide temperature range of operation they make sense when compared to lead acids (often damaged when discharged below 80% due to plate sulphation, acid, hydrogen off gassing) or lithium ion (expensive, discharge to 25%-ish). They are also modular so you can add additional stacks easily when demands increase. lead acids can suffer from uneven charging depending on how you wire them together.

We also will have an immersion diverter which will take whatever excess power is not being used and use it to heat the water in the hot water tank, hopefully meaning that during the summer we will have continual hot water without having to fire up the biomass boiler. That said there will be a "Y" valve in the heating system so that all the water heat will be sent to the water tank and not to the central heating. Having seen several biomass boilers I have decided on the MCZ Musa Hydro 15 as a cost effective (circa £2.2k ish) option.

One of the major snafu's with current PV systems for off grid (which is essentially what we are) is what to do with excess electrical power generated once the batteries are full and there are no other loads on the system. Normally some form of resistance load would have to be included in the system in order to 'soak up' the excess electricity. Not so for ours. It has been designed so that when the systems senses excess power it switches off strings of photo voltaics one by one until it reaches equilibrium. If loads go up like I am using my hair curlers or Hoovering the cat then the panel strings are switched back on again. Clever eh? I was intending to have the system linked via app and wifi but to be honest, if we are roving Europe and various other places, Wifi may be non existent so I have opted for a hardwired display and control panel. If in doubt KISS...

I did mention the cooking option and why I have opted for gas. It may seem like a retrograde step in terms of sustainability and you would be right. Initially I had wanted to fit a Klover Smart 120 as pictured. It is a pellet boiler which heats your water and uses the exhaust gases to heat an oven and hot plate on top. I discussed this with several people including a Klover rep at the Grand Designs show and although a good option for some, it's not really totally suitable in a boat setting. The unit is predominantly a boiler so you need a heat sink/thermal store in order to take the excess heat away, especially during the summer when you may not want to turn the heating on to act as a sink. There is insufficient room on a barge to have a 1 tonne tank for a thermal store unless you have a 50m Spits or Peniche... I am sure that pellet ovens will be developed in the future, but they will always be a compromise or will have to be a dedicated oven. It would have been a great solution, but the physics didn't quite work, hence the compromise of having gas. We will probably have a small electric hotplate and a small combi oven as backup or to use electricity when it's sunny but ultimately we will have gas as our main cooking fuel.

There are currently 4 x 12V traction batteries linked to provide 440Ah of 24V power to an inverter to provide AC and 24v to the NAV/Lights etc which will be kept on a continual float charge provided by the domestic AC. Should this fail then the batteries will provide uninterrupted service to the nav systems, external lights, radios, emergency lights and other critical systems for the operation of the barge. It would seem to be belt and braces to have domestic batteries, soara and wind, a generator and then have a backup battery set for "mission critical systems'. From my time in the military, when the f&ck up fairy visits, he very rarely just tinkers with one thing but takes a hammer and flamethrower to almost everything.

I am back out to Holland via ferry on the overnight this evening for a 10 day demolition fest. With luck the plasma cutter may get an outing... Watch this space for trips to Dutch A&E.