Off Grid Solar / Wind Project

Published on 14 January 2023 at 18:45

Like everybody else I was pretty horrified back in 2021 to hear of massive price hikes that were expected for both gas and electricity. Where we are there is no gas - the nearest main being about 1 mile away so electricity is pretty important to us. We use oil to heat the house, the workshops have no heating other than a gas powered blast heater of 8kw - nowhere near enough really but to keeps the worst of the chill off. Anyway, the machines in the workshop use a fair old bit of juice and my bill was looking like being a couple of hundred quid a month - that takes a fair bit of earning and I resent paying my hard earned cash to a faceless corporation that makes billions while pensioners freeze. So I decided it was time to go off grid as far as I could, I started with the workshops.

I had done a hell of a lot of research and decided that solar would give me the best return on investment, although I obviously had no real world figures to work from so there was a degree of guess work involved. I had calculated that I would need about 2.5kw of panels to provide me with all I need - this turned out to not be enough for the winter months but was plenty in the summer / autumn. i purchased 10 235 watt used pannells, they were about 8 years old with a 25 year warranty so they will be fine for my purposes. Total price including delivery was 720 quid - bargain. I had to make stands for them so I could set them at an angle that would catch the most sun, it depends what latitude you are at sas to what angle you set them. I made the stands out of fence posts and lengths of studding timber, all given a couple of coats of creosote. I dug deep holes and used 2ft long metposts to give me nice firm bases,  coupe of cubic foot of concrete down each hole helped firm things up a bit. It turned out my garden is about 2 inches of top soil and them a couple of feet of compacted rubble. The house was built in 1914 - it was a 90 acre farm, the barn next to it used to be part of the farm but is now owned by the council and rented too a farmer that lives round the corner. When the council sold the house back in the 1980's they split the property, dug up all the concrete apron and just put topsoil down. It was great for my current purposes as it helped build a solid foundation.


I bought a chinese inverter - a Vevor 5kw unit that looked to have the perfect spec for me including a max input voltage of 145Volts. My panels are 30 volt so I could run 4 in series to give me 120. Initially I was going to run 8 panels but as the postage was for up to 10 panels, that's what I went for. I looked at the battery requirements, I wanted lithium ion but they were incredibly expensive and I later found out that the Vevor could not charge them anyway so I got 8 140ah lead acid batteries and configured them as a 48volt 280 ah pack.

While I was at it I completely rewired the outbuildings - a complete pain that took me a couple of weeks but what was there originally was such a hotch potch that I didn't feel I could leave it. I am much happier with it now, every circuit has a decent breaker installed and there are master breakers and isolators for everything that helps massively with servicing.

We went through the Summer well, so well in fact that I decided to feed power back to the house, I isolated the downstairs main ring so that it could be switched to either grid or off grid, we produced enough power for it to drive most things, except the cooker and tumble drier - they remained on grid. In July 2021 our total electricity usage was 6 quid. Of course the thieving tossers still took 14 quid plus vat standing charge but there is not a lot I can do about that with the electricity industry as it is.

When Autumn came and the days got shorter it became obvious that solar alone was not the answer, it also became obvious that more panels were needed so we could catch the late evening sun. I thought I would wait until next Spring to do anything on the solar, I wanted to collect data throughout the Winter first. In the mean time I decided to supplement the solar with wind power, in hind sight I would have spent my money on more solar.

I went for an Istabreeze 1kw generator, I built a mast for it, which is secured to the corner of my workshop - this was a big error on my part. It's great if the wind blows from south to north but pretty much any other direction and it swirls around the building which really interferes with the ability to produce electricity. I would also say that despite having seen it operate in a gale I have never seen it push out the full 20 amps that it is supposed to.

The controller that I bought for it is absolute rubbish. I thought that by spending a but more I would get a better product but that turned out to not be the case. It was advertised as quality German engineering but inside it was all cheap Chinese components and the way it worked was just dumb. It controlled the charge by putting a dead short across the turbine's windings when the battery voltage reached 58 volts. It is the most inefficient way of doing things, with the unreliable components it's also very dodgy as your batteries are at risk of over charging if the relays that short the windings fail - as mine did within a couple of weeks of being installed.

If any of you are thinking of going this route get an mppt controller with dump load - they are so much better, way more efficient and also cheaper. If you are really smart about it you can use an immersion heater as a dump load and use excess power to heat your water.

here's a video of my system in the early days, I will add some relevant photos when I can find where I have hidden them



An off grid solar project with added wind turbine
Off grid solar control panels with inverter

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