On-grid domestic battery storage

chamelion

Petriix said:

arty688 said:

Petriix said:

arty688 said:

Yes, watched yesterday thinking of unsubscribing , even on my most optimistic man maths day my figures are nowhere near. I just wonder how much Givenergy paid him or maybe he is just stupid?

My man-maths are really starting to add up. I've got a spreadsheet with historical generation data which I have adapted to calculate possible savings from various sized batteries.

At my previous rate of 12.6p with Symbio it was around a 14 year payback best case. At 17.6p with Neon Reef it's around 9 years. At Eon's 20.8p it's close to 7 years. With the possible prices in April it could be under 5 years.

The sweet spot seems to be 7.2kWh of pylontechs with a Solis inverter for around £3k

I'm guessing that's with solar ? The EVM video is without
Did you included losses and that the 7.2kwh is 6.5kwh useable which will reduce over time?
Also £3K seems cheap if you are including install

Yes, calculations include 80% round trip efficiency and 80% depth of discharge. Fortunately I'm on deemed exports so no loss there.

I'm looking at £2800 for the materials, then self-install the bulk of it and get a friendly sparky to make the final connection to the isolator I already have connected to the CU.

The numbers are still borderline at current prices ~ £300-400 savings per year. But with more rises in the spring it's going to be a no-brainer. 

what do the materials entail?

I'd love to add another pylontech to my bank but it's impossible to find for a decent price...

arty688

Ok that makes sense , I'm just looking at the post FIT era with no DIY element.

Its hard to tell if electric prices will continue to rise for the next few years but I would say they won't be going back to 2020 prices but gas will go up and up as the idea is to phase it out.

Petriix

chamelion said:

Petriix said:

arty688 said:

Petriix said:

arty688 said:

Yes, watched yesterday thinking of unsubscribing , even on my most optimistic man maths day my figures are nowhere near. I just wonder how much Givenergy paid him or maybe he is just stupid?

My man-maths are really starting to add up. I've got a spreadsheet with historical generation data which I have adapted to calculate possible savings from various sized batteries.

At my previous rate of 12.6p with Symbio it was around a 14 year payback best case. At 17.6p with Neon Reef it's around 9 years. At Eon's 20.8p it's close to 7 years. With the possible prices in April it could be under 5 years.

The sweet spot seems to be 7.2kWh of pylontechs with a Solis inverter for around £3k

I'm guessing that's with solar ? The EVM video is without
Did you included losses and that the 7.2kwh is 6.5kwh useable which will reduce over time?
Also £3K seems cheap if you are including install

Yes, calculations include 80% round trip efficiency and 80% depth of discharge. Fortunately I'm on deemed exports so no loss there.

I'm looking at £2800 for the materials, then self-install the bulk of it and get a friendly sparky to make the final connection to the isolator I already have connected to the CU.

The numbers are still borderline at current prices ~ £300-400 savings per year. But with more rises in the spring it's going to be a no-brainer. 

what do the materials entail?

I'd love to add another pylontech to my bank but it's impossible to find for a decent price...

https://www.solar-energy-store.co.uk/home/Sofar-Solar-ME3000SP-Controller-&-Pylontech-7-2kWh-Battery-Storage-System-p142551715

Apparently out of stock until December but a decent price overall.

QrizB

lisyloo said:

arty688 said:

Oh and not forgetting that the excess solar is worth 5P export.

Which it still will be if it's "deemed" right?

and

arty688 said:

What I was saying was if you unit price is say 20p and you have generated 10kwh excess solar if you had a battery you could store it and use it and it would be worth £2 but take 10% for losses etc so £1.80 the take away the 50p you would have got anyway (export) and the battery has saved yo £1.30. Not the £2 you might think.

Us FIT people on deemed export get paid for exporting 50% of our generation, whether we export it or not. Solar power that we can't otherwise use is essentially "free".

Eg. If I generate 20kWh, I get paid the same amount whether I export 20kWh, 10kWh or nothing. So in your example, there's no 50p to miss out on.

Of course on SEG (or FIT with metered export, rather than deemed) you're right that you've lost the export earnings you would otherwise have been paid. This is what makes solar diverters a bit "meh" if you're on SEG.

(Aside; my FIT is old enough that I'm only paid 3.95p/kWh for export.)

Magnitio

New here. Not sure whether this has been discussed before. Looking at some of the home battery solutions (e.g. Givenergy) they rely on an internet connection and their servers for control and monitoring of the system. If the supplier goes out of business in a few years time, what happens? I guess many other solutions are similar. Are there any that are independent of the internet and allow you to control the flow of power to the battery/house/grid? Are there any examples of suppliers that have gone out of business leaving their customers with solutions that they cannot control/monitor?

Heedtheadvice

You could be stuffed!

It is a risk. Immersun (a diverter manufacturer) went out of business and whilst the device continued to work remote access and control via their server became unavailable but was fortunately taken over by another company. That has not been trouble free but it is still a free service!

It is quite common for systems to be internet based as there are advantages to that such as access from anywhere one can get an internet connection and easy firmware update/fixes.

However I would not want a prime system, such as generation, storage or EV charging to have to rely solely on a remote server. No doubt those with storage battery systems will be along to advise better on that specific aspect.

Petriix

Just make sure whatever system you buy has local network access rather than being fully dependent on a remote server. Most inverters seem to be locally controllable. It may be that you'd lose access to the statistics, but that shouldn't be a major issue.

Magnitio

I checked with Givenergy. They are currently working on enhancements to allow control of the inverter locally if server access is lost.

TangoGolf

Apologies if it's been covered before but as regards local access to the Lux what exactly do you put in the Android app login page. I can't seem to get it to login. It's fine when logging in normally.

EVandPV

TangoGolf said:

Apologies if it's been covered before but as regards local access to the Lux what exactly do you put in the Android app login page. I can't seem to get it to login. It's fine when logging in normally.

Shouldn't need to change anything in the username and password, it's not required for local connect anyway.
Have you changed the wifi network your device is connected on to the ssid of your Lux datalogger ?
Should be something like BA12345678 in your list of wifi networks.