I would guess that people who are in a position to shell out £15000 on solar/batteries probably have that £15000 ready to spend on any number of alternative "life improvement" projects. It you spend it on a new kitchen and associated gadgets you never get that money back. In most cases the old kitchen would continue storing your plates and cutlery and enable you to cook your dinner. If the money was put towards a new car the money would just drain away over time. If you went on a world tour you would have a great time but have none of the money at the end. If you have an expensive hobby that involves sailing, flying, motorsport ... even golf ... the money just goes. So unless you are depending on the investment income from that £15000 (in which case you wouldn't be considering spending it anyway) the solar/batteries scheme definitely looks "less bad" than most other ways of frittering the cash away! If it ever actually pays for itself then that's a bonus.
-
Want to remove ads? Register an account and login to see fewer ads, and become a Supporting Member to remove almost all ads.
EV tariffs - really only 3 at the moment?
- Thread starter DaveW
- Start date
WannabeOwner
Well-Known Member
If you want to spend a lot of money quickly, take up astrophotography
Our 19kwh of batteries and 10.1 kwp of solar have been in place for just over 2 weeks and it's proving to be excellent to load shift. We are on Octopus Go Faster and between the solar and battery, we've used virtually zero peak rate electricity since the install. Some fag packet calculations suggest a payback in around 7 years (without any export credit) but to be frank, I don't really care that much. It's within sensible bounds and gives all sorts of other benefits. Significant independence from daft power costs, ability to run the whole house if there is a power cut, green charging of the car etc etc. Oh and it's also fascinating and satisfying the geek in me. Next step will be automation and linking in Solcast to adjust the overnight charge in line with what solar is forecast for the following day.
With inflation in double digits, big ticket expenditure is not a bad thing.
I'm self installing, so I've saved few quid.
I'm taking the same approach as above.. also,, as I'm fitting it, I can as easily remove.
WannabeOwner
Well-Known Member
let you know if you find anything please ... I've been tooling up to build something, but I haven't found enough time yet.
(Happy to do some sort of collaboration, but time is my issue ... I'm a software engineer by trade)
ACarneiro
Active Member
This is not guaranteed by any means.
Suppliers are under no obligation to keep Time of Use rates. Granted they’re unlikely to disappear but the ability to load shift is a benefit which is completely at the mercy of the energy suppliers and could be gone next month.
I do love the resilience of supply and self-reliance you get in the summer, though
WannabeOwner
Well-Known Member
My money is on Off Peak being replaced with Time-of-Use rates ... (which is fine for Battery / Car charging of course - possibly a bit harder for "Time shift washing machine etc.")
scdoubleu
Member
Tesla had better get their skates on to make Powerwalls compatible with variable/dynamic ToU tariffs... Not holding my breath!
ACarneiro
Active Member
It’s “just” a software update away.
I actually think it’s quite likely they’ll integrate with Octopus.
I don’t know if there are any industry standards for signaling ToU to battery backup units or even some sort of standardised way of passing carbon intensity or cost to the battery software which would then work out the best times to charge or discharge…
Utumno
2 x Model Y LR (2022 Q2 & 2023 Q3)
Or buy a social media platform.If you want to spend a lot of money quickly, take up astrophotography
Or a farm.
Will do but I've bought in to the GivEnergy system which is quite "open". A few of the guys on the various Giv forums have already developed systems to do this - python, "GivTCP" or combinations, so the heavy-lifting has already been done. There are also quite a lot of tutorials using Home Assistant but I've not really dug into that yet. I think a few of the users may also be on this forum but not entirely sure.
The GivEnergy system has a few quirks which are actively being addressed but overall it's excellent. The company is also growing fast and some of the support is a bit flaky at the moment, (think Tesla back in 2019) but assuming they get on top of that, I think they're on to a winner.
Agreed but I'm pretty hopeful that "Time of Use" tariffs will be here for some time yet. This is where the GivEnergy system comes into its own with quite a lot in the pipeline to link directly to these types of tariffs. I recently stuck over 10 kwp of solar on the roof so worst case is we'll end up supplementing with peak rates 4 or 5 months of the year. Even today which has been pretty cloudy, we've covered the house background plus some of the office load with solar.This is not guaranteed by any means.
Suppliers are under no obligation to keep Time of Use rates. Granted they’re unlikely to disappear but the ability to load shift is a benefit which is completely at the mercy of the energy suppliers and could be gone next month.
I do love the resilience of supply and self-reliance you get in the summer, though
This is where I think I may have dodged a bullet by not going with Powerwall. I looked hard at that first but then decided on the much more open GivEnergy system to facilitate this. Interestingly they've just released a new product which looks to be a direct competitor to Powerwall. Similar specs with islanding etc but also the open GE control architecture.
It's supposed to be available in March but I suspect it will be several months after this. Lots of folk waiting to see what the realistic date is. Pretty sure it's going to be very popular.
ACarneiro
Active Member
WannabeOwner
Well-Known Member
The API to PowerWall looks OK to me (some exceptions), but so far all that I have found is boy's-own stuff, no polished 3rd party APP.
The only negative I've seen (in powerWall API) so far is inability to tell it to charge up. You can set the reserve to 100%, which will achieve that, but the rate of charge is "modest" which means, for example, that it won't fill up in a 4 hour slot. So still have to set an "Off Peak" slot for the overnight period (which does, then, charge "flat out"), but that's only useful during Winter, and in Autumn / Spring the ability to adjust it dynamically would help a lot ... in Spring I need it to definitely NOT fill right up overnight because although the day does not have enough to charge the battery to 100% (i.e. I need to start the dday with some "grid charge") the sun is up at, say, 7AM and therefore the amount of discharge from end of off peak, to sun up, is not enough to prevent export (if the battery is at 100% at end of Off Peak)
Basically, I want to set a MAX CHARGE "Reserve" based on a prediction for tomorrow's sun and then command "Charge FLAT OUT". Currently I would need to (manually) adjust the timeslot for OFF PEAK rate ...
So once the API allows "Start charging from GRID" (i.e. flat out!) then just setting reserve will be enough ... I reckon!
ACarneiro
Active Member
Yes, I suspect with the proper attention to software or a decision to open up to third parties, the Powerwalls could become really quite something…
Similar threads
