Octopus Import vs Export Tariffs

Gynx

Short question but surely I'm missing something here.


I can be on Intelligent Octopus Go, charge a home battery up over night at 7.5p a unit then sell it back to them in the morning at 15p a unit ?

Really?

(Table taken from the Octopus site)

Netexporter

Yes, lots of people do it.

QrizB

Yes, that's what the table says.

Any other questions?

(OP sceenshot is from here.)

MWT

... although most will use it to avoid paying 30p+ during the day over winter at least...

Gynx

Im assuming there is fair usage or something?

Although I guess if it someones plan to make a decent amount off it, a 10kwh battery at £4000 would still take 11 years to pay for itself.

QrizB

Gynx said:

Im assuming there is fair usage or something?

The tariff is intended for EVs which could be using 50kWh/day, or more. Another few kWh for a home battery isn't going to be a big deal.

Gynx said:

Although I guess if it someones plan to make a decent amount off it, a 10kwh battery at £4000 would still take 11 years to pay for itself.

And that's the problem with home batteries. Prices still haven't fallen far enough to give any assurance that it's any better than a savings account or a conventional investment in eg. a SSISA.

pete-20-11

If I've got my maths right, assuming 20% loss converting it to DC to store in the battery and then back to AC later, circa 6p profit per kWh? 

Might not be as bad as 20%, but still sounds worth doing, if you don't need that energy yourself of course. 

noitsnotme

Gynx said:

Short question but surely I'm missing something here.


I can be on Intelligent Octopus Go, charge a home battery up over night at 7.5p a unit then sell it back to them in the morning at 15p a unit ?

Really?

(Table taken from the Octopus site)

Yes but only if you have a compatible EV or charger for Intelligent Octopus.

TheElectricCow

Gynx said:

Im assuming there is fair usage or something?

Although I guess if it someones plan to make a decent amount off it, a 10kwh battery at £4000 would still take 11 years to pay for itself.

Well you’d first need to buy an EV/compatible charger, a suitably sized home battery, and any associated equipment to go along with those. Then you need to factor in losses from charging/discharging the battery as well as the additional wear on the system, and not forgetting to ensure you’ve enough energy stored to use yourself - no point in exporting it all for ~6p/kWh profit if you’re going to need to buy that energy back at 30p/kWh later in the day. 

But with the above taken into consideration, yes, it could prove worthwhile to do for someone who owns the appropriate equipment, and it is encouraged by Octopus on other tariffs. The Flux tariffs for solar owners for example are designed around this principle by having reduced import rates at off-peak times and increased export rates at peak times. Intelligent Flux in fact will manage the charge/discharge of the battery for you in a similar way to how Intelligent Go manages car charge times.

Probably not a great money saving idea to purchase a whole setup with the specific intent of just import/exporting though, as the payback time would be long and tariffs could change in the future.

Reed_Richards

I don't have a compatible EV so I would have to buy a compatible charger, costing maybe £1000.  My usable battery capacity is about 5.5 kWh so if I could make 6p per kWh profit that would give me 33p per day.  So I would have paid for the cost of my EV charger after only about eight and a quarter years.