Solar batteries retrofit thoughts

djmattc

Hello all
I've had a solar system recently fitted and it's really annoying me that I'm generating three times more electricity than I need but still needing to pull power from the grid at night.
I've looked in to battery solutions but can't seem to find a lot of information on it, mainly around price and reviews.
So I was wondering if anyone on here has had a storage solution retrofitted to their existing solar system. I read an article that the Enphase system is cheapest as you can dip your toes in by getting a small system to start. It said they were approx £1000 to start but the lowest quote I've had is £2999 for a 1.2kWh system!
So, where do I get quotes from? Which system is best? Which system is cheapest? Is it worth waiting until I've had my panels in for 12 months? Is battery technology moving so quickly that I will regret having a system installed after 5 years?
My system is 3.5kWp.

silverwhistle

djmattc wrote: »

Is battery technology moving so quickly that I will regret having a system installed after 5 years?

No.
Probably after 2!

Joking aside the situation does seem to be changing rapidly and that's just from what I read on these forums. Hopefully someone with a bit more expertise will be along soon, but you are not alone in your experience particularly at the moment. I heat my immersion tank and then I'm exporting like mad. At some stage I hope to get a S/H electric vehicle and that should improve matters.

ASavvyBuyer

Take a look at this topic on the forum.


Lots of info and discussion there.

Merlin139

How much electricity do you use at night? Is it more than a couple of kWh? How much is that costing you per night? How long would it take to recover the cost of a storage system?

While you are probably generating more during the day for maybe 6 months of the year wait till the winter months and you are lucky to get 3 kWh's during the whole day.

Can you make better use of whats generated during the day? Put things on timers. Yesterday I could have filled a 10 kWh battery in 3 hours but would not have used all of its power over night so it would have been 2/3 full in the morning when I would have been generating more spare power.

Until systems get cheaper you just need to get better at using what you generate.

djmattc

Using about 2-3kWh per night.
I'm at work all day so it's not possible for me to properly utilise the energy I'm using, unless it's at the weekend, hence why I'm looking at battery solutions.

pinnks

Hi and welcome to the mad house!

A lot of us are watching the battery economics in the hope things become viable "soon" but at the moment you have to be greener than green with a load of spare cash to nudge the market in the right direction for the rest of us...

Your night-time consumption will be higher in winter than in summer given the longer periods of darkness, higher use of lighting and heating pump etc. So if you are using 2 to 3kWh now you might average as much as 5kWh per day over the year. At about 13p per kWh that is about 65p per day (assuming that you could charge the battery in winter with reduced generation).

So, a maximum saving of perhaps £250 per year but more likely to be some way below £200.

That should give you an idea of how the maths will pan out for you if the cost is £1,000, £2,000 or more likely double that at the moment.

Does it make financial sense to invest with a 30 plus year expected breakeven period, given that the battery will probably need replacing at least once in that period, thus extending to perhaps a lifetime?

Unless something happens somewhere to accelerate things (government subsidies somewhere in the world), I think we are still a few years away from things looking even mildly viable.:beer:

hawkwinddotcom

I presume that the expensive part of a battery setup is the batteries?
So if I had a source of batteries (over 6000 on UPS's at work) what would I need to get?

Ectophile

Unless your inverter is already designed to talk to a battery, it's unlikely to make any financial sense at all.


I had a new inverter and battery system installed at the beginning of this year, but only because my old inverter had already failed.


Realistically, I may never get the extra cost back from having the more expensive inverter and the battery fitted.


I'm a light user, so at this time of year I never manage to run my 3kWh battery flat. During the winter, it was a different matter. On a sunny day, I could usually eke it out to last the whole evening, but on a wet day, the battery might barely charge at all.

hawkwinddotcom

Its a solaredge se3000