Cost analysis for batteries (ROI)

[Windbag]

I really can see the enjoyment in running a battery storage solution.

I am grid negative (if that's even a thing) I produce more than I use.

But I can't make batteries add up financially, there is no roi, it's a cost.

Am I missing something?

[Caesium]

If you're already producing more than you use and not importing anything, I can easily see your point being correct. Batteries won't really add anything for you. They're not necessarily a money making machine, not everything has to have an ROI

In my case I've been able to timeshift usage from Octopus GoFaster peak rate (40p) to the cheap rate (still 8.25p for a while yet) so thats 32p saved per kWh I shift. That makes the maths a lot more palatable.

I'll shortly be adding some solar and the batteries will obviously let me store what I can't use at the time for later. The maths for this actually makes less sense than timeshifting, I could just buy the energy at 8.25p. I'd have to use a LOT of overnight energy for this to pay back. But eventually that tariff will expire, and besides, it's fun

Besides earning you money they have other applications - retaining power in a power cut is the most obvious one.

[Joeboy]

If you are grid negative all the time Windbag (a precursor)? then they're not for you. They work well for a lot of us.

Caesium has pretty much nailed it.

Personally,I bought 13.5MWh from the grid last year, if in a perfect world if I bought 100% of that for home use at my cheap rate then it would have saved me £4,725 over the high rate.

Having batteries in one form or another allowed me to move considerably further away from FF.

To access the cheap rate I have an EV, another battery form which I can use to run the home.

The greatest aspect of 'battery life' for me is the catching of the passing electrons in a dynamic weather environment which would otherwise be gone. I get a lot of dynamic weather, the battery solution nulls out all the peaks and troughs.

Also being able to be doing it for yourself and your family without relying on someone else (grid) is pretty epic. I might make all my money back or maybe not. Its not even on my priority list and I never ran the figures, I wanted the 'Life'.

[ClockmanFRA]

Batteries, yea hhmm!

I find that Industrial Flooded Lead Acid, IFLA, are still the best cost effective solution for a Home back up battery bank. But i doubt if you will find much ROI info on them for obvious reasons.

We are talking Fork lift FLA . 600ah to 1500ah or the modern Jargon, 30KW to 75KW.

There is normally NO issue with the weight or sizer of IFLA in a normal domestic household, and mostly its wise to have them on a rack in a outside lean-to shed/building.

I sometimes despair at the vested interest nonsense spouted out from distributors and manufacturers of these modern so called wonder batteries, as they slate FLA.

LIFE PO4 types of chemistry seem to be holding reasonable well from my friends around the Globe who installed about 30KW of storage about 10 years ago. However, several have had issues with the BMS systems and the below freezing conditions. One mistake and they are toast.


Okay cost IFLA…… last year I had 2 quates from a Polish Firm called BATER, they are a manufacturer, but not sure if they manufacture the complete IFLA or they import some components.? They state that a normal pack used daily was good for between 10 and 15 years life. However, I know if the pack is look after expect a 20 year life.
A 600ah 48v, that’s 24off 2v IFLA batteries was £6k and a 1200ah 24off 2v IFLA was £9K. Then Tax and transport, however getting them into the UK might be expensive ? Those prices also includes a special battery rack.

We have 30KW RE generation and have a IFLA 1500ah 48v over 15 years now, and they are slowly loosing Ah but voltage good, so another few years and i need to go shopping.

I trust this helps.

[ALAN/ALAN D]

Could it be that your Grid meter has got stuck / packed up working.

If you had a battery / inverter system it would Help your Barrister / Solicitor reduce the amount you will have to pay if they fix the meter.
Barrister hourly charge in London £525 per hour. Probably V.A.T. To pay on top. Not sure.

I have got 36 P.V. Panels and a 3 K.W. Wind turbine. Battery system. But my smart meter still wants me to pay money at times.

[marshman]

Batteries, yea hhmm!

I find that Industrial Flooded Lead Acid, IFLA, are still the best cost effective solution for a Home back up battery bank. But i doubt if you will find much ROI info on them for obvious reasons.

We are talking Fork lift FLA . 600ah to 1500ah or the modern Jargon, 30KW to 75KW.

There is normally NO issue with the weight or sizer of IFLA in a normal domestic household, and mostly its wise to have them on a rack in a outside lean-to shed/building.

I sometimes despair at the vested interest nonsense spouted out from distributors and manufacturers of these modern so called wonder batteries, as they slate FLA.

LIFE PO4 types of chemistry seem to be holding reasonable well from my friends around the Globe who installed about 30KW of storage about 10 years ago. However, several have had issues with the BMS systems and the below freezing conditions. One mistake and they are toast.


Okay cost IFLA…… last year I had 2 quates from a Polish Firm called BATER, they are a manufacturer, but not sure if they manufacture the complete IFLA or they import some components.? They state that a normal pack used daily was good for between 10 and 15 years life. However, I know if the pack is look after expect a 20 year life.
A 600ah 48v, that’s 24off 2v IFLA batteries was £6k and a 1200ah 24off 2v IFLA was £9K. Then Tax and transport, however getting them into the UK might be expensive ? Those prices also includes a special battery rack.

We have 30KW RE generation and have a IFLA 1500ah 48v over 15 years now, and they are slowly loosing Ah but voltage good, so another few years and i need to go shopping.

I trust this helps.

I get where you are coming from but I would make 2 observations/comments:

1. "However, several have had issues with the BMS systems and the below freezing conditions. One mistake and they are toast."
A properly constructed housing with moderate insulation and a heat mat should overcome the majority of low temperature situations - here in the UK properly sited installs don't have issues. And again a properly designed and installed system should not be just relying on the BMS alone, most inverters have voltage and current upper limits which if set correctly act as a second line of defence should the BMS fail. FLA and IFLA batteries can suffer from lack of proper maintenance by the ignorant, and as far as I know do need periodic checking of electrolyte levels etc, which LiFePO4 cells don't

2. Cost. A bank of 32 x LF280K cells giving 560AH at 48V (28kWh of which at least 22.5kWh is accessible on a daily basis for full 6000 cycles) sourced from China. can be built (DIY style) for £3600 all in delivered to your door in the UK tax and duty paid. That's for 32 cells, BMS with full inverter coms, flexible busbars, epoxy dividers etc. If you allow for the useable capacity of FLA being less than that of LiFePO4 then to me that is around half the cost you quoted for IFLA.

Not saying there aren't still situations/applications where FLA are not more suitable but I think the "wonder batteries" are better suited to the UK domestic market - don't forget many houses over here are restricted on space both inside and outside - not many have the relative luxury of large fields and outbuildings. "Wonder batteries" can be installed in the roofspace, under the stairs or where ever, the energy density is far greater than FLA so the "packs" are smaller (and lighter). Each of my 28kWh packs weigh in at just under 200kgs and measure 1.3m long x 0.6m wide x 0.25m tall (overall enclosure size). How big is an equivalent IFLA pack (with 22kWh of useable capacity!).

[ALAN/ALAN D]

Went to a mates house back in 1970 after returning from the Pub.
Noticed while standing outside by the front door letter box a very strong smell of Sulphuric Acid.
When he opened the front door. I had to Bash his arm very quickly. He was trying to turn on the hall light. It stopped the explosion. The batteries on charge in the hall had sulphuric acid spewing out of the top onto the carpet / up the wall. Where the battery charger had gone wrong.
I Still did not learn much. Wasted lots of £ on lead acid batteries over the years.
Well impressed with the LIFEP04 batteries. Apart from the battery lugs as supplied.

[Windbag]

Sorry. I am grid negative (annually), however I do still shower on foggy days so I import. But I am going to check my numbers again.

I agree some things you do just for fun & nurdery.
But the wind & solar for me was an interesting and enjoyable investment. But I struggle to make batteries add-up. Some of the battery bank retailers make some wild claims. Wondered if it's was me.

Batteries in cars are a brilliant idea to microgrid, apart from the cars don't work fur me either physically or financially.

[Stinsy]

Sorry. I am grid negative (annually), however I do still shower on foggy days so I import. But I am going to check my numbers again.

I agree some things you do just for fun & nurdery.
But the wind & solar for me was an interesting and enjoyable investment. But I struggle to make batteries add-up. Some of the battery bank retailers make some wild claims. Wondered if it's was me.

Batteries in cars are a brilliant idea to microgrid, apart from the cars don't work fur me either physically or financially.

Interestingly there have been many people recently installing batteries without the solar because the payoff from batteries was better than solar!

[Marcus]

If you're motivated by ROI, then you're probably right, the numbers might not stack up - but it does beg the question of what tariff you're on? Some folks on here seem to make it work by timeshifting loads with the battery, but that does involve some inconvenience in having to start /stop loads depending on time of day - if you're grid negative I'm guessing you're doing that anyway to some degree?