Octopus Power Loop

[Rooster6655]

Just seen this on an advert looks interesting, seems Nissan Leaf only at the moment and a limited area.

https://www.octopusev.com/powerloop

My only concern if I had a leaf apart from the battery degradation would be Octopus and their customer support but should be interesting how it develops over the next few years

 

[ItsNotAboutTheMoney]

Just seen this on an advert looks interesting, seems Nissan Leaf only at the moment and a limited area.

https://www.octopusev.com/powerloop

My only concern if I had a leaf apart from the battery degradation would be Octopus and their customer support but should be interesting how it develops over the next few years

CCS V2G standard has not been finalized so it's always CHAdeMO only.

In trials, V2G hasn't shown any additional degradation, and in fact may help reduce it due to lowering the SoC.

 

[Glan gluaisne]

I have very grave reservations about the whole concept of V2G, given that the cycling requirement for grid support is absolutely massive when compared to the normal cycling pattern seen by an EV battery. Cycle life isn't a big driver for EV battery design, as EVs never really cycle their battery packs very much at all. As a consequence, cells intended for EV use are designed to accept high charge and discharge rates, and have a long calendar life, but they never really need much in the way of cycle life - the equivalent of 1,000 full cycles is more than enough for the typical lifetime of a car.

For example, take an EV with a range of 250 miles, that's driven 10,000 miles a year. It will undergo the equivalent of around 40 full battery cycles a year. In comparison, a battery pack used to provide grid support is going to cycle at least once a day in winter, and probably twice a day for most of the summer. It will easily undergo ten times more cycles per year than the battery pack in a car.

There are battery chemistries that are better suited to being cycled a lot. LiFePo4 is one, and the chemistry used in the well-proven Pylontech packs, that have around ten times the cycle life capability of LiCoO2 or NMC cells. They have nowhere near the energy density, but this doesn't really matter for a stationary pack assisting the grid - size and weight aren't major design considerations for such an application.

The reason that so much work is being done on other bulky, but very high cycle life battery chemistries, like redox flow cells, is related to this requirement for a very high cycle life for battery packs intended for grid support. Ideally, these batteries need to last for decades, with little or no loss in capacity.

 

[ACarneiro]

Yes, I have grave reservations as well unless there is some sort of guarantee from Tesla that they will cover any hypothetical early battery degradation. And even then...

I do wonder why this tech is being pushed so hard. I suppose it’ll be in preparation of more resilient batteries in the future...

 

[ACarneiro]

Having read the FAQ, this is done with leased cars, so no personal risk as such.

“It's important to point out that there’s no risk for Powerloop bundle customers because the cars are leased from Octopus Electric Vehicles, which means we take the risk on any battery degradation. Nissan are also the only manufacturer to include V2G operation as part of their warranty - a major factor in using the Nissan LEAF.”

It will be fascinating to see the results from this

 

[Fred2]

I don’t think the cycle counts would be as much as 10x higher - car batteries are a lot bigger - the powerwall is one of the bigger ones and is only 13 kWh.

Before EVs i used to use about 3500 kWh per year - if 100% of that went through the car (which it won’t - car isn’t always at home for starters) and if I had a leaf with a 40kWh, ie a small battery these days, then that’s 90 cycles extra a year, for a car that would need 60-70 cycles for that hypothetical 10,000 mile a year.

i still wouldn’t gamble my battery on it, but as others have said since the octopus deal is all leases, they’re taking the risk.

 

[Glan gluaisne]

I don’t think the cycle counts would be as much as 10x higher - car batteries are a lot bigger - the powerwall is one of the bigger ones and is only 13 kWh.

Before EVs i used to use about 3500 kWh per year - if 100% of that went through the car (which it won’t - car isn’t always at home for starters) and if I had a leaf with a 40kWh, ie a small battery these days, then that’s 90 cycles extra a year, for a car that would need 60-70 cycles for that hypothetical 10,000 mile a year.

i still wouldn’t gamble my battery on it, but as others have said since the octopus deal is all leases, they’re taking the risk.

V2G has nothing to do with home energy usage, though, it's about putting power into the grid for everyone, including industry, to use during peak periods, and taking power out of the grid during off-peak periods in order to charge the battery. It's all about arbitrage, as there is a great deal of money to be made by buying electricity during off-peak periods, when the price may well be close to zero, and selling it during peak periods, when the price could be as high as 75p/kWh.

 

[Durzel]

Yeah it’s worth being clear that this is Vehicle to Grid, not “Vehicle powering my own house when it’s charged”.

Also this is (wisely) a whole package deal. You’d be interested in it primarily if you wanted a Leaf anyway, and want cheaper electricity to run it.

Would be interesting to know the numbers relative to running your own personal Powerwall(s) and solar, for your house & car demand. I assume it isn’t as cost effective as you aren’t actually generating electricity from this solution.

 

[Glan gluaisne]

Would be interesting to know the numbers relative to running your own personal Powerwall(s) and solar, for your house & car demand. I assume it isn’t as cost effective as you aren’t actually generating electricity from this solution.

We have over 6 kWp of solar, and cannot hope to make a battery installation pay for itself before it dies of old age. During the winter months solar doesn't generate enough to more than cover the house baseload most of the time, so there's nothing much spare to go to a battery. During the summer months there is loads of excess solar generation, but it's far more than the house could possibly use, even if it was stored in a battery, just because demand from the house in summer is lower (we're all electric, heating and hot water, no combustion appliances at all).

We generate about 6 MWh/year and consume about 5 MWh/year, but about 56% of that consumption is during the 7 hour off-peak period (we've time shifted heating, hot water, washing machine etc to that time already). Any saving from having a battery would come mainly from being able to reduce the cost of the 44% of peak rate usage, by charging during the off-peak period. A small saving would come from being able to store self-generated excess electricity during summer, but not a lot, as we don't use much then.