Investing in a small GivEnergy battery to access Intelligent Flux

Screwdriva

Greetings,

I’ve long aargued against batteries for low import households…the advent of the Intelligent Flux tariff has prompted a revisit of the numbers, despite the 1550 kWh annual import.

As the owner of a SolarEdge system, adding a AC coupled GivEnergy 2.6kW battery would cost ~£2K including AC/DC controller. 

The goal here would be to “pay” the least amount of £ to access the Intelligent Flux tariff, which is itself an infinite battery, and export at a 45% higher rate over the standard Flux tariff.

Would welcome any wisdom from IOF end users!

MallyGirl

Relatively new IOF user here but it works well for us. We have the 13.6kWh AIO battery, 6.2kW panels. We do the big export from the battery between 4 and 7pm - well Octopus does it for us of course - but also any solar being generated in that window also gets exported at the higher rate. With our WSW facing panels we are still generating decent amounts during the peak window.

Screwdriva

Thanks! 

Flux is currently ~16p per kWh and IOF is ~23p per kWh for the day export rate. Thats a 44% premium for ~8 months of the year. Given we will generate approximately 6000kWh, of which we will export 5000kWh and consume 1000kWh of Solar, while importing 1600kWh from the grid, the £2K spend on a tiny battery is looking somewhat attractive, regardless of what Octopus does with control of it.

Looking purely at excess solar export earnings:

5000kWh X ~18p = £900 on Flux
vs. 
5000kWh X ~25p = £1250 on IOF

Grid import costs will rise as the cost of import is higher than on Flux (25p vs. 20p) but this is mitigated by the low import and the capacity (albeit small) of the battery to some extent. Looking like a <7 year return.

Hmm....

charles_b_2

As the owner of a SolarEdge system, adding a AC coupled GivEnergy 2.6kW battery would cost ~£2K including AC/DC controller. 

@Screwdriva , I was under the impression that it's only the AIO that works with Intelligent tariffs from Octopus?

Screwdriva

charles_b_2 said:

@Screwdriva , I was under the impression that it's only the AIO that works with Intelligent tariffs from Octopus?

I believe all GivEnergy batteries work with IOF. The AIO is the only battery which offers a 6kW charge/ discharge rate and whole house backup. Realistically, this is the only battery for high consumption households who want access to IOF. Enphase and Tesla batteries are next. 

My goal here is to see if I can gain access to the IOF tariff without prioritizing storage capacity for household usage or charge/ discharge specs, as we are a low import household.

charles_b_2

If you are low import, then you can effectively stop import and still take advantage with a small battery, so good idea. 

I misunderstood then on the AIO, so any Givenergy battery/inverters can then work with IOF - that's good.
I'm almost completely off-grid now.  My spend on Agile (not intelligent) is around 9p per day from around £4 per day before solar.  Once I get paid for export, then I should be negative cost for most of the year.  Too early to tell what my annual saving will be, but I'm getting better than expected generation which is a huge bonus.

Alnat1

Do Octopus give any indication how long they will support this tariff for? Are the prices fixed for any length of time or can they be changed?

Screwdriva

Alnat1 said:

Do Octopus give any indication how long they will support this tariff for? Are the prices fixed for any length of time or can they be changed?

Your guess is as good as mine but it does appear to follow the flexible price cap, as does Flux. 

MallyGirl

email last week:
Intelligent Octopus Flux rates track Flexible Octopus prices, so your import and export rates are falling from July 1 as well.
We are high users over the year (7000kWh) but not particularly high in summer so we are exporting (from battery and generation) lots more than we are importing.
For example 10-16th June we exported £55 (200kWh) and imported £25 (113kWh). That is pretty typical at the moment.
We will switch to a different tariff for winter as we will have some electric heating on then and will want to be shifting that activity to an early morning cheap rate (I think).

pete-20-11

In an ideal world I think the rule of thumb is get a battery that is big enough to cover your daily consumption, but not too big - as you might not get a return in investment (not that everyone worries about that).

Of course tariffs like IOF then complicate the matter, as for most of the day the grid is your battery! So all you need is a big enough battery to get you through the three hour peak.

An important note re battery capacity and charge/discharge rates...

A 2.6kWh givEnergy battery can only charge or discharge at 1.3 kW.

So if you turn on the kettle at 5pm you might end up pulling from the grid - eating into the profits.

A 5.2kWh battery will discharge at 2.6 kW.

The AC3 inverter can discharge at 3 or 3.6kW I think, but is limited by the battery in the above two cases.

If you get a battery that is bigger than the 5.2, then the limit will probably be the inverter at that point. 

Also note that the 2.6 kWh and 5.2 kWh batteries are not 100% depth of discharge. Some of the battery is reserved for health reasons. For example the 5.2 kWh battery is 4.1 kWh usable. Thus it will run out quicker. 

The 2.6 kWh is probably around 2.1 kWh usable. 

Plus is the difference in battery cost worth it - if you've got to get an accredited electrician in to install the battery and inverter, that will be a lot of the cost. Going for a slightly larger battery maybe worth it. 

Similar to the concept of solar panels - when you've got to pay for scaffolding you may as well get as many panels on the roof as you can. E.g. panels are cheap, scaffolding and install costs aren't. 

pete-20-11

Screwdriva said:

charles_b_2 said:

@Screwdriva , I was under the impression that it's only the AIO that works with Intelligent tariffs from Octopus?

I believe all GivEnergy batteries work with IOF. The AIO is the only battery which offers a 6kW charge/ discharge rate and whole house backup. Realistically, this is the only battery for high consumption households who want access to IOF. Enphase and Tesla batteries are next. 

My goal here is to see if I can gain access to the IOF tariff without prioritizing storage capacity for household usage or charge/ discharge specs, as we are a low import household.

I had an AC3 on the IOF tariff and swapped it for a Gen 3 hybrid (don't ask lol).  Same batteries. 

Both of those inverters worked fine with IOF.

I had heard rumours of issues onboarding to IOF where people had more than one battery. Not sure if AIO is troublesome to onboard too. But it defo worked for my AC3 and my Gen3 hybrid.