Your Powerwall 2 App settings adv. mode with Solar PV and Octopus Agile

[jimbo_hippo]

Hi all, Firstly, apologies for this being in UK and Ireland rather than the dedicated Energy section but it's rather UK specific.

Wondering how you folks with a similar setup to ours have your App configured.

SETUP:

- 5.9kW of Solar, Tesla Powerwall 2 and we will be on Octopus Agile soon (smart meter fitted today).

- Nissan Leaf as a second car and a Model 3 arriving in a fortnight.

- two adults working from home so able to charge cars, washing etc daytimes if we have excess

Rather than being a dumb 'questioner' I've looked at setting up my peak and off-peak times and studied the pricing examples from Octopus. Based on this I've used the attached screen grab as my base settings. I've made the assumption that the off peak is best set to night-time hours. Because you can toggle the off-peak on or off, leaving it on would appear to create a third price between these hours as a kind of 'No Man's Land' area where anything goes, if available. As a winter setting in Lancs, I wonder if this may be a good option but it is a presumption.

Because of limited solar on many winter days in the UK I've opted for cost saving mode over balanced as an attempt to force Powerwall charging off peak during the winter months when it's hard to get the Powerwall full.

I've mimicked the weekday settings on the weekend settings as I see little difference between the two but I'll be monitoring it.


I'd be interested in how anyone with a similar setup and lifestyle has their app configured with the Agile Octopus Tariff specifically.

 

[VanillaAir_UK]

Firstly, apologies for this being in UK and Ireland rather than the dedicated Energy section but it's rather UK specific

Bet it wont stop you getting answers that have no relevance to our region

... or no relevance to your question think of it as a bump...

 

[gangzoom]

This is our setup for Bulb E7 rates, only had it installed just over 1 week, works very well, pretty much all our 'peak' grid usage is now PW + solar. Using 'Cost saving' option.

Last 2 nights have been the first time the PW hasn't charged to 100% overnight, I presume the software is 'learning' how much solar can be generated in 1 cloudy UK November day, did pretty well today PW was 99% full just before the sun disappeared after starting the day just above 90%

I've looked the Octopus Go but 4hrs of off peak just isn't enough for our EV use at weekends, and on a rain/wet winter day we can get through the whole PW before 10pm, having the morning 'peak' electricity use of kettle/toaster etc on come in before 'Peak' hours helps. Good thing about Bulb E7 is in summer time the E7 rate is from 130am-830am, so we are actually out of the house before E7 rates end

 

[ACarneiro]

How much does the Powerwall draw when charging?

Would I be able to charge 2 EVs (32A each) as well as a Powerwall at off peak times?

 

[jimbo_hippo]

This is our setup for Bulb E7 rates, only had it installed just over 1 week, works very well, pretty much all our 'peak' grid usage is now PW + solar. Using 'Cost saving' option.

Last 2 nights have been the first time the PW hasn't charged to 100% overnight, I presume the software is 'learning' how much solar can be generated in 1 cloudy UK November day, did pretty well today PW was 99% full just before the sun disappeared after starting the day just above 90%

I've looked the Octopus Go but 4hrs of off peak just isn't enough for our EV use at weekends, and on a rain/wet winter day we can get through the whole PW before 10pm, having the morning 'peak' electricity use of kettle/toaster etc on come in before 'Peak' hours helps. Good thing about Bulb E7 is in summer time the E7 rate is from 130am-830am, so we are actually out of the house before E7 rates end

GangZoom, Great to see your interpretation. But Agile is a little different. With Agile, you're linked to the wholesale price every 30mins so you have to bridge the peak time with the Powerwall or Solar to win the gamble the tariff brings. So whereas you're seeing anything except your nightime as peak, so daytime is really just another fixed rate, Agile can go sky high with the market at peak (but it's capped at 35p by Octopus) and any time is 'open season' although the night time can be ludicrously cheap.

 

[jimbo_hippo]

How much does the Powerwall draw when charging?

Would I be able to charge 2 EVs (32A each) as well as a Powerwall at off peak times?

The Powerwall draws max 3.5kW if I remember correctly ACarneiro. My app seems to confirm this right now with 3.5kW going to the Powerwall and Nissan Leaf drawing the rest but now tailing off to about 2kW at the end of its charge. Bear in mind the LEAF only draws 3kW max at any time (2017 with the slower inbuilt charger) and my Tesla isn't here yet so I don't know how the Gateway prioritises if you're charging 2 EVs and you've set up your Powerwall to charge off peak. I have to wait a another 2 weeks to know that.

 

[ACarneiro]

I’d be very grateful if you could post that information. Can’t quite afford solar and Powerwall at the same time right now so was thinking of starting with Powerwall for load shifting...

 

[gangzoom]

GangZoom, Great to see your interpretation. But Agile is a little different. L.

Thanks, I've looked at their data before, can I ask why are you going for this traiff instead of E7 ot Go?

The data from last year showed the agile price was less than 8p per kWh only 2.3% of the time, where as on E7 with bulb its 29% time your paying that price.

I find it hard to believe your pay less on agile even with a Powerwall than standard E7.

Am still not even sure Go works if your a heavy EV user, our X can charge for 7hr solid and still not be at 90% SOC If you arrive home with sub 10% after a road trip. And in current weather you really don't want to be leaving home without less than 80%.

 

[gangzoom]

The Powerwall draws max 3.5kW if I remember correctly ACarneiro. My app seems to confirm this right now with 3.5kW going to the Powerwall and Nissan Leaf drawing the rest but now tailing off to about 2kW at the end of its charge. Bear in mind the LEAF only draws 3kW max at any time (2017 with the slower inbuilt charger) and my Tesla isn't here yet so I don't know how the Gateway prioritises if you're charging 2 EVs and you've set up your Powerwall to charge off peak. I have to wait a another 2 weeks to know that.

When I charge the Tesla as 32amls it seems to bypass the our PW completely and just pull straight from the grid regardless of PW SOC. I haven't tried limiting it to 16amps or lower, but that rate of charge is really slow on our X, and even if you emptied 13kWh of the PW thats barely 20% SOC added over a long period of time.

 

[gangzoom]

Just did quick EXCEL plot - which then crashed.

Average price of Agile prices in E7 time is 10.5p per kWh, with no set time when the cheap rates are. Seems like a lot of hassle to pay more, so why bother?

 

[VanillaAir_UK]

I’d be very grateful if you could post that information. Can’t quite afford solar and Powerwall at the same time right now so was thinking of starting with Powerwall for load shifting...

Certainly use to be the case that if you had other related work as part of solar install you got lower rate VAT on the whole job. It would be a big saving on Powerwall. However I think rules may have changed and PV install may no longer qualify for lower rate VAT.

You need to crunch the numbers on a Powerwall - the economic numbers for Powerwall at standard price are hard to justify and certainly does not justify itself environmentally on TOU only due to round trip losses > 20% last user info I saw. In our scenario when I crunched numbers of actual 5 minute usage pre 5p rate or EV was payback way outside the usable lifetime of the unit. The big gotya is power and energy limitations on battery storage.

 

[ACarneiro]

Yes, the economics on load shifting alone aren’t there, but I was viewing this a the first stage, with eventually a solar roof in the future...
Probably more sensible to wait until powerwall prices come down, I suspect.

 

[gangzoom]

Probably more sensible to wait until powerwall prices come down, I suspect.

The irony is PW prices have been going up in the last 12 months + Gateway 2 is more expensive now as well!

Across the broad lithium ion battery prices are stubbornly high.

Interestingly a sub £10k 24kWh Leaf if probably the best 'value' large battery grid storage solution there is.......if you have the skills needed to decouple the battery and use it!

 

[VanillaAir_UK]

The irony is PW prices have been going up in the last 12 months + Gateway 2 is more expensive now as well!

Yep. When an install was 5k I was expecting it to fall, but as you say, it went the other way although I suspect most of the increase is ancillary items and fitting. About 4 years back, so Powerwall 1 days, my break even point financially was a little under £3k. I need to rerun my calculations with current use case, but do not expect financial break even to have changed much. However, this time I plan also to build in CO2 effect too, so not just monetary.

 

[redelectrical]

The Powerwall draws max 3.5kW if I remember correctly ACarneiro.

Hi all, new to this forum having just come across this post.

As a Tesla Certified Installer I wanted to clarify that Powerwall 2 has a maximum charge and discharge rate of 5kW provided it has been set up in G99 mode by the original installer. If it doesn't ever exceed 3.68kW then it has probably been set up in G98 mode.

The settings can be changed with prior approval from the Distribution Network Operator (DNO). Any Tesla Certified Installer can do this, it just requires an application to the DNO. My local DNO is quite generous when it comes to what they allow us to connect but certain other DNOs are not. The reason some installers choose to use G98 mode is because it is a quicker application process but in my opinion they're not being fair to their customer who deserves to enjoy the full capabilities of their premium battery system.

I run a similar system to the OP with 6kWp of solar, a Powerwall and the Agile Octopus tariff.

Kind regards
Stuart

 

[Dilly]

I run a similar system to the OP with 6kWp of solar, a Powerwall and the Agile Octopus tariff.

I’m on Octopus Go at the moment. Am I right in thinking that the Powerwall can’t be configured to follow the agile tariff?

 

[Country Boy]

Hi

I have power wall, Solar, an Ioniq and a Model 3.

When the power wall charges from the grid, it usually limits itself to 3.6kW, but I have on occasion seen it up to 5kW,

You need to be very careful with the maximum load... 2x32Amp charger, 21 Amps to power wall.. Run the dishwasher 10amps and you have blown your suppliers 80 amp fuse, and risking a 100amp fuse.

I have a zappi charger...a great bit of kit... It has current sensing, so will reduce charge rate if you are getting close to the maximum your DNO can supply. It will also handle the solar diversion to the cars... It works impeccably. Can't recommend the zappi enough.

 

[Dilly]

Hi

I have power wall, Solar, an Ioniq and a Model 3.

When the power wall charges from the grid, it usually limits itself to 3.6kW, but I have on occasion seen it up to 5kW,

You need to be very careful with the maximum load... 2x32Amp charger, 21 Amps to power wall.. Run the dishwasher 10amps and you have blown your suppliers 80 amp fuse, and risking a 100amp fuse.

I have a zappi charger...a great bit of kit... It has current sensing, so will reduce charge rate if you are getting close to the maximum your DNO can supply. It will also handle the solar diversion to the cars... It works impeccably. Can't recommend the zappi enough.

I second that. My two V1 Zappi’s have been great.

 

[IanL]

I’m on Octopus Go at the moment. Am I right in thinking that the Powerwall can’t be configured to follow the agile tariff?

Bit late to this thread, but you are correct there is no direct integration other than with the Tesla energy/Octopus Telsa tariff. There are "hacky" options out there to control the Powerwall from a local raspberrypi or a third party integrating with the cloud API. Hopefully they'll open up a more usable portal like myEnergi have done with the Zappi or the Ohme charge cable.

That said, it is easy enough to run the Powerwall in cost saving mode and set off-peak period to the cheapest Agile times (don't change that often) and the peak time to the most expensive peak times (never change). The only things that need a bit of monitoring are if the shoulder times are spiking like this week, or there are price plunges at odd times. Otherwise it is pretty set and leave, and you can safely know you are avoiding using any peak electricity and always charging at off-peak times.

I ran some numbers and Agile is still cheaper than Go for me, even with the expensive (no wind, low nuclear) prices last week. I definitely had some days when Go was cheaper, but very small %. Over the last 30 days (a bad month) Agile was 28% cheaper than Go overall. If I compare Agile cost with and without powerwall time-shifting (assuming 18% usage and 20% round trip loss) I save a similar amount. (That is in the depths of winter with very minimal solar. Summer numbers should look better as there will be limited charging needed from grid and can still avoid peak charges from just solar). I gave percentage numbers there as everyone's consumption is different, but it will still depend on usage patterns.

 

[ACarneiro]

I thought the Powerwalls were rated for 90% round trip efficiency?

I personally can’t be bothered will all the Agile work so just got on Go. I can charge my batteries at 5p per kWh and that is just under half what my previous Economy7 rate was. Complete no brainer