[No longer] Going for a Givenergy 8.2 kWh AC Coupled battery

Solarchaser

Welcome to the world of man math justification Petrix.

What I'd say is the chance of you avoiding all high priced import is basically 0.
I'm using about half and half, and thats with 20kwh useable, but high usage.

Part of that is electric showers which use around 10kw when the parallel lux will only really cover 7kw, some is the fact I have no weather management factored into my charging, it relies on me watching the weather and deciding whether to charge or not, the rest is basically because your inverter has a lie time to respond to consumption changes, and this means you will always import some. 

Petriix

Solarchaser said:

Welcome to the world of man math justification Petrix.

What I'd say is the chance of you avoiding all high priced import is basically 0.
I'm using about half and half, and thats with 20kwh useable, but high usage.

Part of that is electric showers which use around 10kw when the parallel lux will only really cover 7kw, some is the fact I have no weather management factored into my charging, it relies on me watching the weather and deciding whether to charge or not, the rest is basically because your inverter has a lie time to respond to consumption changes, and this means you will always import some. 

I think I can avoid most of the peak usage. Yes, the delayed response will have an impact, but I have nothing high-powered like a shower - we swapped ours to one that runs from the gas boiler.

I'm reasonably happy to tweak the grid charging based on the weather. I'm hoping that the Givenergy system will work as advertised in terms of charging to a set threshold at a set time so I can automate some of the logic depending on the time of year.

Solarchaser

I wish you all the best with it.
It will be interesting to see how the GivEnergy responds/performs 

Reed_Richards

Petriix said:

The alternative (with a hybrid inverter) is a complicated dual meter setup where you record how much grid energy goes into the battery and deduct that from your FIT readings. 

My generation meter does this automatically; I had not realised it was not a standard feature.  It tells me the amount of electricity exported and imported and the default reading is the difference, which is the export reading for FiT purposes.  I'm not on a tariff that makes it economic for me to deliberately charge my battery but if the state of charge falls really low (5% ?) then the inverter will add a little charge automatically.  

Petriix

Reed_Richards said:

Petriix said:

The alternative (with a hybrid inverter) is a complicated dual meter setup where you record how much grid energy goes into the battery and deduct that from your FIT readings. 

My generation meter does this automatically; I had not realised it was not a standard feature.  It tells me the amount of electricity exported and imported and the default reading is the difference, which is the export reading for FiT purposes.  I'm not on a tariff that makes it economic for me to deliberately charge my battery but if the state of charge falls really low (5% ?) then the inverter will add a little charge automatically.  

That makes sense. I assume you had batteries from the outset which would necessitate a meter capable of reading it accurately. Mine is just a basic, dumb digital meter.

Reed_Richards

Yes I did have a battery from the start.  This is the meter that was fitted: https://www.metermarket.co.uk/product/eastron-sdm230-modbus-mid-single-phase-100a-direct-connected-energy-meter/

mikereynolds

I have an 8.2kWh GE battery, fitted in November. 4kWh PV system, now 10 years old.
Very impressed with it and its reduced our daily 6kWh down the around  0.6, so pretty happy with that.
Moved to Economy 7 in Jan22 with new  meters and began to notice serious differences in reported readings. The system shows we are importing generally 50% of what the Grid Meter shows and some 5% lower on generation. GE don't appear to be concerned, or even interested in trying to rectify the problem and are blaming the PV system, which is reporting to better than 0.5% accuracy.. 

MikeHEQA

Reed_Richards said:

Yes I did have a battery from the start.  This is the meter that was fitted: https://www.metermarket.co.uk/product/eastron-sdm230-modbus-mid-single-phase-100a-direct-connected-energy-meter/

Can you say what inverter and make your are using with this meter.... thanks

Toogie

Swan_Valley said:

We have 2 GivEnergy 8.2kWh batteries (recently installed as we had to wait months for them to be available).

Very happy with them, the App & the web portal.

We are using them to power our 2 A2A ASHP throughout the day, to avoid using GCH.

Charging them up overnight on 5p/kWh & top up during the day from excess solar.

Swan_Valley said:

We have 2 GivEnergy 8.2kWh batteries (recently installed as we had to wait months for them to be available).

Very happy with them, the App & the web portal.

We are using them to power our 2 A2A ASHP throughout the day, to avoid using GCH.

Charging them up overnight on 5p/kWh & top up during the day from excess solar.

I’ve been running my 4kWp array through a GivEnergy 3.6kW hybrid inverter very happily since last December too. My GivEnergy 8.2kW battery is on back order and am wondering if it will ever arrive but Glowgreen tells me ‘yes but not when. 

I have an Octopus SEG account giving me 4.1p/kWh for excess solar whilst I have no battery to soak it up but future exporting income is not a primary driver for me. Currently using 50% of generated solar in the home. 

I’m ditching my 20yr old gas boiler in a couple of months for a Tepeo zero emissions electric (ZEB) boiler and I need to acquire enough battery storage -but not too much that the resource will be underused -to top up the ZEB’s 40kW stored energy on the coldest of winter days when solar is unavailable and the cost of Octopus Go day rate (13.45p/kWH for me this year- inevitably more next year) would make the import leckky costs so much more than gas. 

I’m thinking of test running the single battery set-up through the winter to see if I need a second battery- if so, it would have to be the 9.5kW, a replacement for the 8.2kW promised for later this year. 

I’m interested in comments/ suggestions on the above. 

QrizB

Toogie said:

I’m ditching my 20yr old gas boiler in a couple of months for a Tepeo zero emissions electric (ZEB) boiler and I need to acquire enough battery storage -but not too much that the resource will be underused -to top up the ZEB’s 40kW stored energy on the coldest of winter days when solar is unavailable and the cost of Octopus Go day rate (13.45p/kWH for me this year- inevitably more next year) would make the import leckky costs so much more than gas. 

...

I’m interested in comments/ suggestions on the above.

Storing electricity to provide heat is an unconventional choice, although (as you've got solar) it won't go unused outside of heating season.

Could you keep your boiler and burn gas in the cold, dark months of the year, at least for the first year or two while you get a feel for how much extra heat you'll need?