On-grid domestic battery storage

Reed_Richards

https://pasteboard.co/IaOvQFH.jpg

I don't know if this will work but this linked chart shows my overnight energy usage and how it drains my battery. Presumably it is the fridge and freezer draining the power until I and my boiler wake up at about 6:30. My battery was fully charged until about 6 pm yesterday and was down to about 35% when I woke up this morning

Martyn1981

Reed_Richards wrote: »

Yes I did know this. But knowing battery vehicles are capable of instant power I was curious as to why the battery in my solar system cannot, or is not allowed to, do the same.

I'm only guessing here, but I suspect it's about the battery size and application.

BEV's, being cars, are expected to deliver a lot of power on demand, and have big batts to back that up, whereas a smaller stationary battery can be software limited to reduce strain on it and maximise cycles, with targets perhaps 4x that of car batts (6,000 v's 1,500),

In the case of the big Tesla's, you see acceleration rising as packs get bigger, and ludicrous mode allowing even faster acceleration but with disclaimers about potentially greater battery degradation, so presumably 'hitting' those batts harder and faster is not good for them.

I strongly suspect that the Tesla Roadster's enormous range (600 miles) isn't because they thought buyers wanted that much range, but because they needed something like 200kWh of batts to be able to pump out enough instantaneous power to meet the acceleration stats.

1961Nick

Reed_Richards wrote: »

https://pasteboard.co/IaOvQFH.jpg

I don't know if this will work but this linked chart shows my overnight energy usage and how it drains my battery. Presumably it is the fridge and freezer draining the power until I and my boiler wake up at about 6:30. My battery was fully charged until about 6 pm yesterday and was down to about 35% when I woke up this morning

My battery went from 100% to 39% over that period...7.3kWh

Our house has been powered by sunshine since 6:45am on Monday.:cool:

Shocking statistic....:eek:
Electricity used April 2012: 1662kWh (pre-PV)

Imported energy April 2019: 55kWh (18 days)

joefizz

If you lot think my last post was long, you should read my blog...


Anyway, few things....
solic - do you actually need it now? Ive always had a push button timer on the immersion so manually set it now off the battery. If so , check where the clamps are for the sensing and make sure they are at the end of loops etc. Im not sure about layout and it may not be doable but drop me a pm if you want or just put a post up in this thread about that and maybe the hive mind will sort it (or not ;-))


Had my first non deliberate low voltage alert this month on Wednesday (solarman, go to alerts and then use the month pull down to see when low voltage alerts were), sun was supposed to be out but three days running low fog/haze three days/mornings in a row had me emptying the battery for an hour weds 930-1030. Thats not bad going.


Had the ASHP going on monday night to replace first oil boost, bedroom dropped to 19.5C which was tolerable, had it running all through the night last night set at 21C and bedroom stayed at 20C or above and it was 5C outside here last night. Battery down to 28% by 7am but now 50% at 10am.



Yesterday ran dishwasher, hot wash on washing machine and tumble dryer all at once, veritable kwh fest and only dropped about 3% (really good solar output though). Even had the ASHP on air con at one point!!



Out to do the garden today, lawnmower, hedge cutter, rotivator etc


Reed, one of the things I found with the pylontech as martyn mentioned was that the software limits the amount of current supplied depending on the battery capacity (hence the reason I doubled mine, not really to get the extra capacity but more to provide the extra load current when running the immersion). Id also check if you have a sky+ or virgin+ box. When I had those (been a few years now) I think I measured the standby at around 90-100W. !!!!!!! really! They might have improved though.
That does seem quite a bit of kick in for a fridge and freezer though, looks to be on more than its off. I have a fridge and 3 freezers and dont get close to that.



Very particular about my tea/coffee as well so got one of the morphy richards one touch kettles/hot water dispenser (43922), better than the breville or tefal as the water is as close to boiling as you will get. Cant see it now on their website though...
I dont use a water filter but my mate has a very good under sink system with separate small tap on his kitchen sink, cheaper overall on the replacement filters and its under mains pressure and can be used then for everything.

Solarchaser

Reed_Richards wrote: »

https://pasteboard.co/IaOvQFH.jpg

I don't know if this will work but this linked chart shows my overnight energy usage and how it drains my battery. Presumably it is the fridge and freezer draining the power until I and my boiler wake up at about 6:30. My battery was fully charged until about 6 pm yesterday and was down to about 35% when I woke up this morning

Your graph looks similar to mine, however I have a pretty big American style fridge freezer, and it tops out about 140w, I mean it looks to me like maybe a door seal is away and the compressor is on for longer, and more often to compensate.

Interestingly as I was typing this, I got a phone call from the energy saving centre (why are these conmen allowed to call themselves things like that??) Telling me I never have to buy electricity again if i get their amazing solution... batteries.

Obviously I told them it was a downright lie:mad: and take me off their database, but it gives you a bit of an idea why so many "optimistic "claims here are shot down so viciously :rotfl:

zeupater

1961Nick wrote: »

My battery went from 100% to 39% over that period...7.3kWh

Our house has been powered by sunshine since 6:45am on Monday.:cool:

Shocking statistic....:eek:
Electricity used April 2012: 1662kWh (pre-PV)

Imported energy April 2019: 55kWh (18 days)

Hi

Similar stats:
Electricity Used April 2012: 97kWh
Electricity Used April 2010: 204kWh (pre-PV)

Imported energy (including gas!) April 2019 (to 14:30 today): 46kWh

.... no gas, no battery, managed efficiency, no shock! .... :cool:

HTH
Z

1961Nick

zeupater wrote: »

Hi

Similar stats:
Electricity Used April 2012: 97kWh
Electricity Used April 2010: 204kWh (pre-PV)

Imported energy (including gas!) April 2019 (to 14:30 today): 46kWh

.... no gas, no battery, managed efficiency, no shock! .... :cool:

HTH
Z

But you don't share a house with the Kilowatt-Queen.:D

I'm ashamed to say how much gas I used in April 2012.....it must have been a cold month?? I'm expecting minimal usage this month because the CH has been pretty idle so far.

Anyway, 5 consecutive days without any import is a result...and the forecast suggests several more to come.:cool:

Reed_Richards

joefizz wrote: »

Reed,....That does seem quite a bit of kick in for a fridge and freezer though, looks to be on more than its off. I have a fridge and 3 freezers and dont get close to that.

Between midnight and 6 am today the state of charge of my battery dropped from 73% to 68%. It's a 6.5 kWh battery so that's 325 Wh or 61W average power consumption over the 6 hours. Does that seem unreasonable for a fridge and freezer and router?

1961Nick

Reed_Richards wrote: »

Between midnight and 6 am today the state of charge of my battery dropped from 73% to 68%. It's a 6.5 kWh battery so that's 325 Wh or 61W average power consumption over the 6 hours. Does that seem unreasonable for a fridge and freezer and router?

That looks pretty reasonable. My base load is 250w-350w overnight but the Ice Queen does have 3 fridge freezers & the Sky box is very reluctant to go into standby.

orrery

1961Nick wrote: »

That looks pretty reasonable. My base load is 250w-350w overnight but the Ice Queen does have 3 fridge freezers & the Sky box is very reluctant to go into standby.

I'd second that. My background usage is probably 250 to 400w, with several freezers and quite a lot of computing equipment (a music server and CCTV).