As we continue to grapple with our growing solar PV power station, we’re learning how to manage within our means, power wise (or not on occasion); and get it all running smoothly. Although we have batteries as a buffer, there are some things better done on a sunny day, such as running the washing machine, and with a little careful juggling we can get away without using any mains at all. The idea is that once we can go a month ‘solo’, we can make the phone call to NIE and get the supply removed. Publishing our data live online and here on the website is a way to help others who are thinking of doing the same thing, as well as allowing us to keep an eye on how the system is behaving. We’ve also written some custom code which we think may be the first time someone has connected to the Victron system to pull information out to an external website.
It is, however a process of trial and error, and some errors are more expensive than others. Take for instance our AGM Gel batteries – over the summer we took our solar panels down and they sat around on the roof for months, during which time the batteries never properly charged. In the process, at least one of them has been rendered pretty much useless, and the others now only hold about half the charge they did when new. We’re running on a spare set until we can afford to put in a big set of traction batteries, but have learned just how carefully batteries need to be charged if they are to last as long as they should.
Our PV array now totals a full 4kw, and we just have a few last panels to mount on frames so that they are off the ground, and free of shade. We didn’t think we would be this close to being fully off grid for power just as soon, so to be within weeks of this is real cause for celebration for us.
Having become so involved in the whole off-grid power scene, we also have an exciting development afoot in association with an off grid equipment supplier, so watch this space, we will be announcing something soon..
We are trying to set up an off grid eco campsite and twin unit caravan.
We have only small energy requirements and have been quoted what seem crazy figures for off grid systems.
Can you give us an idea of how much your system cost and what it includes.
I think we will be going for a system of log boiler, log range, 4.5kw solar PV and back up generator possibly a couple of thermal solar panels also.
Hi Elspeth – 4.5kw is a fair bit for a campsite; are you sure you need that much? Solar is around 50p/w at the moment, so for that system you’d need to allow £2200 for panels, potentially another £1500 for batteries, and £2000 for chargers, inverter and cable etc. I would look carefully at what your power requirements are, so the wattage of things being used and the time they will be used for each day.
Log burner wise, I would keep a close eye on gumtree and try and get one there. Old Rayburns and the like etc do come up for a few hundred pounds and will do the job well. Generators – again depends on your power needs, and range from a few hundred to maybe £1500 for a reasonable remote start that is quiet. Solar thermal – £1500 for a basic setup. Have you considered alternatives such as compost heated water using woodchip and a big coil of buried pipe? It works well and is a good way to provide hot water for showers.
Our figures would be similar to the above, though sometimes we have swapped / bartered for equipment, or (as in the case of the panels) been lucky and been given them. You’ll find very cheap solar gear on ebay, but I would warn you that the longevity often reflects the price.
If you need any help sourcing things or with ideas, drop me an email.
Cheers
Steve