On-grid domestic battery storage 5 December 2016 at 4:57PM edited 30 November -1 at 1:00AM in Green & Ethical MoneySaving 1.8K replies 200.1K views

EVandPV

It can be as simple as ‘fit and forget’ or you can tinker with it like some of us either to squeeze every last penny of savings out of it or just because you enjoy hacking/modding  things.

For me, it’s a bit of both. I have a script running which charges the batteries when Agile prices are low and another running on a Raspberry Pi controlling a relay using the batteries as a ‘buffer’ when diverting spare pv to our immersion heater. 

We had our system installed last December so it’s given me something to play with during lockdown while I’ve had some spare time on my hands.

In the summer, you can pretty much just leave them to do their thing.

In the winter, you’ll probably want to at least set up a grid charging schedule to take advantage of cheaper leccy at different times of the day (assuming your on a time of use tariff).

But that’s about it really if you don’t want to go any further than that.

joefizz

Pile_o_stone said:

From reading this thread and battery threads on other forums, it almost seems that people need to have a degree in Electrical Engineering when they have a battery installed. I was therefore wondering if it's the case that batteries are as 'fit and forget' as solar panels but that, as the forums are frequented by people who are hobbyists, they like to tinker with the tech. Or is it the case that this is a new technology and a lot of refining and technical knowledge is required to get them to work?

Thats sort of chicken and egg ;-) I tinker with it because I have  a degree in electrical engineering and know if I duck it up I can probably recover it. Probably!

Most are install and forget and the vast majority of people will do it that way. The types of battery and your background knowledge will ultimately decide the price you pay for install. If you can do the work yourself and are happy with a modular system that either needs a bit of tinkering/fettling or can be installed piecemeal then you are going to pay less than one of the out of the box install and forget systems. Its probably because this is a moneysaving site that you get a lot of the former ;-)

I havent tinkered with mine in ages but it was useful (and ultimately more expensive) to build it up and measure my usage and the 'value' I was getting from my system. 2 years on and 2 'upgrades' later Im pretty much at the leave well alone part. I could have just bought the entire thing in one go and saved myself the extra VAT and shipping to NI charge but wanted to see if half my current capacity would have been enough. It would have been but what I have now allows me to do so much more in the summer, but I needed a full years data to make that decision.
In real terms most of the tinkering doesnt amount to much, although things like upping capacity to allow full battery use to power the immersion led to savings in oil usage which then led to installing an ashp. The higher capacity has also allowed stuff like running a hot tub for the last 2 weeks without making a dent in my imported electricity. The month before I did 4 beer home brews with the same result. My 2 monthly electricity bill has just come in at 3.12 yes three pounds and twelve pence....
...which is great if you gloss over the almost 10k everything electrical has cost me... ...but thats about 50-70 quid every 2 months I no longer need to find and all part of the plan to FIRE.