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Discussion Starter · #1 ·
Good morning all.....

I just wanted to get other users opinions of the Tesla Plan (through Octopus Energy).

A bit about me: Have 4.2kw Solar array, Tesla Powerwall and Tesla Model 3 LR.

Tesla Plan has flat rate import / export at 8p per kw.

I've been on this plan for coming up to a year (I switched to it last March). In theory, the plan seems really good - with one of the highest export rates (if not the highest export rate per kw). However, for me - it doesn't seem to be working - in that my chargeable electricity consumption has more than doubled from when I was on the Go Faster plan.....

So here's how it's working for me (and I want to check if it's the same for other users):

  • Year round - Powerwall charges from grid in early hours of morning to 100%.
  • Any solar throughout the day is used for home use and exported to grid
  • Powerwall starts discharging itself at 4pm - until it's 0% - exporting the full capacity back to the grid
  • Home power usage has to come from grid in the evening / overnight
  • Repeat.......
The good thing is I can charge the car at any time for 8p per kw.

However, when I was on Octopus Go - with no export tariff - the usage was much much lower because the battery never drained, charged by solar (or cheap rate electricity during the 4 hour period in the winter) - we ran whitewoods (washer/ dishwasher, etc) either during periods of high solar generation or overnight cheap rate depending on the weather. My chargeable usage has more than doubled in this year.

If you're on the Tesla plan - have you found the same?

Thanks for reading

Alan
 

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Following.. have 4kWp + Powerwall being installed in next few weeks. Have been trying to work out what the benefit of Tesla Plan might be. Suspect sticking with GO and signing up with Bulb’s SEG @5.38p/kWh would probably be a better option.
 
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Have a larger solar install (4.2kWp originally and then enlarged it with DNO blessing to 6+ kWp last year) and had a Tesla Powerwall installed at the same time, and hoping to get Tesla M3 LR in the next 2-3 months.(changing from a BMW i3).
Our Feed in Tariff payments only apply to the first 4.2 kWp solar array, as got in just before it ended so we get 3.79p/kWh import and 5.24p/Kwh export as things stand.

Have read up on the Octopus Tesla tariff and this was EXACTLY my concern as stated by the OP. You give control of the PW over to Octopus to feed the grid, whenever they want or need to. But I was wondering how often that would be in real life. The OP seems to have answered my question.

As things stand, as we generate a lot of electricity now, (south facing roof also), we can run in its entirety off solar during the day, and then the PW every evening, even on not that much sunny days. And this shows the benefit of the large 13.5 kWh Tesla PW and also its ability to supply the house at up to 5kW if needed (7.5kW peak apparently).

Irrespective of the "cheap" tariff of 8p/kWh, this is not as cheap as "FREE!" which we can utilise most days from March to late September. If Octopus were to leave you with a fullish PW most days for most of the year, it would be a great deal but as suspected, Octopus will use ALL your evening PW stored energy to supply the grid, most days according to Alan. Leaving you to run off the grid to supply your home and charge the car, most of the time. Negating the reason for installing such a system in the first place.

That may change over time when many more people have PWs or other storage batteries but that is most likely a few years off at least.
 

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Discussion Starter · #4 ·
Have a larger solar install (4.2kWp originally and then enlarged it with DNO blessing to 6+ kWp last year) and had a Tesla Powerwall installed at the same time, and hoping to get Tesla M3 LR in the next 2-3 months.(changing from a BMW i3).
Our Feed in Tariff payments only apply to the first 4.2 kWp solar array, as got in just before it ended so we get 3.79p/kWh import and 5.24p/Kwh export as things stand.

Have read up on the Octopus Tesla tariff and this was EXACTLY my concern as stated by the OP. You give control of the PW over to Octopus to feed the grid, whenever they want or need to. But I was wondering how often that would be in real life. The OP seems to have answered my question.

As things stand, as we generate a lot of electricity now, (south facing roof also), we can run in its entirety off solar during the day, and then the PW every evening, even on not that much sunny days. And this shows the benefit of the large 13.5 kWh Tesla PW and also its ability to supply the house at up to 5kW if needed (7.5kW peak apparently).

Irrespective of the "cheap" tariff of 8p/kWh, this is not as cheap as "FREE!" which we can utilise most days from March to late September. If Octopus were to leave you with a fullish PW most days for most of the year, it would be a great deal but as suspected, Octopus will use ALL your evening PW stored energy to supply the grid, most days according to Alan. Leaving you to run off the grid to supply your home and charge the car, most of the time. Negating the reason for installing such a system in the first place.

That may change over time when many more people have PWs or other storage batteries but that is most likely a few years off at least.
Hi - yep - it's every single evening that they drain the Powerwall - leaving me no choice but to purchase electricity from the grid, and out of pocket. I was trying to check that this is what's happening to other people, but I've spoken with Phil this morning from Octopus, and he gave me the impression it's working as designed - hence the 8p import and 8p export - but that doesn't take in to account my electricity usage evenings and overnight. The exported electric throughout the day just doesn't pay enough to cover the costs - especially September to March.

I also noticed today, that due to the software Config of the Powerwall, that once it's charged from the grid in the early hours, almost all of my usage throughout the day is from the grid - bypassing the stored energy in the Powerwall. So for me, it's just not working.....

Hmph
 

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Discussion Starter · #5 · (Edited)
Following.. have 4kWp + Powerwall being installed in next few weeks. Have been trying to work out what the benefit of Tesla Plan might be. Suspect sticking with GO and signing up with Bulb’s SEG @5.38p/kWh would probably be a better option.
I didn't know I could be on import tariff with one supplier, and export tariff with another. Just taken a look at Bulb's website - it sounds like a plan! Think I'm going to move back to Octopus Go-Faster with no export to Octopus and sign up to Bulb SEG.

Alan
 

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Thanks for a fascinating and informative posting.

I have been considering the Tesla Plan for some time (with 4 kW solar installed in 2014) but couldn’t understand the real gain to the user and your feedback reaffirms some of my own conclusions. I could not make sense of the Tesla/Octopus online savings calculator and have only this week had an exchange with Octopus where I concluded a potential saving of only £ 200 pa against Octopus GO tariff. £ 200 saving doesn’t sound like an acceptable return where one is surrendering control of a valuable piece of kit.

Over the past year or so I have tried out Octopus GO, GO Faster, and Agile and have averaged between 7 and 11 p per kWh including the standing charge. I have returned to GO as it suits our lifestyle best with a regular charging time.

With a quoted battery efficiency of around 90% users of this plan are paying for the losses incurred in charging and recharging the Powerwall. Tesla/Octopus are using the Powerwall to maximum advantage during the penal 4 to 7 pm period when figures for the export have reached a maximum of over £1 per kWh at times per an Octopus/ Tesla Owners UK online event. If you have a power cut then you can only reserve a small proportion of the capacity for your own usage. A further issue is that the life of the battery appears to be measured in the number of cycles of the battery and per your feedback the battery will be well used at the end of any period on the plan.

Thanks once again!
 

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I didn't know I could be on import tariff with one supplier, and export tariff with another. Just taken a look at Bulb's website - it sounds like a plan! Think I'm going to move back to Octopus Go-Faster with no export to Octopus and sign up to Bulb SEG.

Alan
Reason I started looking around was because Octopus say on their website that you can’t be on Outgoing Octopus whilst also on GO. I queried this with them and they‘ve now told me I could be on both, but at an OO rate of 3p/kWh exported. So, if you wanted the same supplier for both import and export, it’s is now possible on GO.
 

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Discussion Starter · #8 ·
Just checked the usage from the Powerwall - grid electricity.

In year 1 - full year - imported from grid 3431kw of electricity - on Octopus Go (and go faster tariff)

Year 2 - full year - imported 9319kw (but I did export 3183kw) - so essentially paid for 6136kw of electricity on Tesla plan.

So it’s almost doubled my grid usage.

Crazy!


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Although the 8p/8p figures look cost neutral, you are presumably suffering conversion losses, so you are using more overall with the level charge / discharge happening now?
 

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Although the 8p/8p figures look cost neutral, you are presumably suffering conversion losses, so you are using more overall with the level charge / discharge happening now?
Yes you’re paying for the conversion loss.

It’s a good plan if you have a large solar array and/or consume a lot of power already (large house with electric space/water heating, or a heated pool, several electric cars, lots of teenagers etc) but it’s more like you forefit the powerwall to get access to the 24/7 cheap import rate and good export rate. FYI my 8.3kw array was often exporting a lot but at 0p/kWh in summer with Octopus Agile.
 
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I have struggled with this for the past 3 months. I have a 7kWp array and a PW2. I do not own a Tesla so I would be on the 11/11 plan. Running the Octopus suggests that my import and export would be broadly equal so my annual energy cost would be zero. I agree that Bulb export SEG (5.38p/kWh) and Go might be a better option that Agile import/export.
 

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Year 2 - full year - imported 9319kw (but I did export 3183kw) - so essentially paid for 6136kw of electricity on Tesla plan.
Out-of-interest, how do these figures compare with the figures produced by the Octopus Tesla Plan Calculator? Has your annual consumption changed between Year 1 and 2?
 

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Are you sure your import has actually doubled in the last year and that there isn’t another reason than switching to the Tesla plan? It does seem too large to be attributed to just the Tesla plan switch. Do you have a faulty smart meter? In fact do you have a known L&G E470 100mm Powerwall2 compatibility issue version that needs replacing?
 

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Discussion Starter · #14 ·
Hi, I had the smart meter replaced last year - after receiving an email from Tesla about it.

Those figures I put above are from the powerwall grid import powerflow screen over the year.

But if you think about it, the powerwall charges to full capacity every night (13.5kw), then the house uses a mixture of grid (mostly) and solar (a little) throughout the day, battery discharges itself back to grid 4pm-6pm, then houses grid power all night.

Whereas before Tesla plan, solar charged the powerwall and house usage (when available) and powerwall charged a little overnight during off peak hours, along with the car....

Still trying to work things out, but I’ve got no other explanation for it....


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In year 1 - full year - imported from grid 3431kw of electricity - on Octopus Go (and go faster tariff)

Year 2 - full year - imported 9319kw (but I did export 3183kw) - so essentially paid for 6136kw of electricity on Tesla plan.
Something is wrong with those numbers...

If the PW2 is emptying itself daily and there is nowhere for your excess solar to go other than the grid because the battery is full then the export number is too low as that doesn't even cover the PW2 emptying itself daily..

Similarly even if the PW2 is filling itself daily, that plus your previous annual consumption is still lower than the amount you imported in year 2 ...

It feels like your house consumption is significantly higher in year 2 than in year 1 ...
 

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Discussion Starter · #16 ·
Ah - you’re right - I don’t know why - working from home for a year? Not being able to eat out (which we did a few nights a week)? car plugged in for the majority of the time? I’m not sure what else has changed....

But - the mix of where that energy has come from has changed significantly:

2019 energy sources (home use)



2020 energy sources for home use:



So the grid usage has risen from 40.9% to 65.9% and solar usage has dropped from 24.4% to 13.2%. So the overall mix of where the energy came from for the house has changed.

I guess though my overall point was that having no control over the powerwall - since Tesla set up the config and I’m locked out of that part - means that I use grid power every single night after the powerwall has discharged to the grid.

Alan


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Thanks for the additional numbers.

You'd expect the mix to change if the house consumption is up, especially if you were not exporting much/anything to the grid before, as the additional consumption can only be met by additional import from the grid.

The lack of control point is understood, but with the tariff set to the same price for import/export and the round-trip losses on the daily full Powerwall charge covered by the lack of a standing charge, from a financial perspective you shouldn't need to care if your evenings are powered by the grid or by retained solar as the cost impact is neutral.

The real question is can you beat 8p/kWh by being on Go or Agile...

Last year I managed to hit 9.6p/kWh on Agile, including the standing charge, but with no solar or battery.

This year it isn't going to be anywhere close to that as the Agile prices have gone up a lot over the first 5 weeks compared to last year for the same period (17.5p vs 10p).

Go would have been cheaper so far this year, but even there I wouldn't have got close to 8p/kWh.
 

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Hi, I had the smart meter replaced last year - after receiving an email from Tesla about it.

Those figures I put above are from the powerwall grid import powerflow screen over the year.

But if you think about it, the powerwall charges to full capacity every night (13.5kw), then the house uses a mixture of grid (mostly) and solar (a little) throughout the day, battery discharges itself back to grid 4pm-6pm, then houses grid power all night.

Whereas before Tesla plan, solar charged the powerwall and house usage (when available) and powerwall charged a little overnight during off peak hours, along with the car....

Still trying to work things out, but I’ve got no other explanation for it....


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Do you have other apps/tools that you can export the last couple of years import data and do comparisons with?
If you have been with Octopus and have smart meter data, you should be able to compare the import and the solar inverter should have data to confirm the approx. generation. Export is not easy to download unless you have some other monitoring equipment.
I have years worth of daily manual meter reads for import, export and generation so have a fall back set of baseline data to check trends.
 
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Good morning all.....

I just wanted to get other users opinions of the Tesla Plan (through Octopus Energy).

A bit about me: Have 4.2kw Solar array, Tesla Powerwall and Tesla Model 3 LR.

Tesla Plan has flat rate import / export at 8p per kw.

I've been on this plan for coming up to a year (I switched to it last March). In theory, the plan seems really good - with one of the highest export rates (if not the highest export rate per kw). However, for me - it doesn't seem to be working - in that my chargeable electricity consumption has more than doubled from when I was on the Go Faster plan.....

So here's how it's working for me (and I want to check if it's the same for other users):

  • Year round - Powerwall charges from grid in early hours of morning to 100%.
  • Any solar throughout the day is used for home use and exported to grid
  • Powerwall starts discharging itself at 4pm - until it's 0% - exporting the full capacity back to the grid
  • Home power usage has to come from grid in the evening / overnight
  • Repeat.......
The good thing is I can charge the car at any time for 8p per kw.

However, when I was on Octopus Go - with no export tariff - the usage was much much lower because the battery never drained, charged by solar (or cheap rate electricity during the 4 hour period in the winter) - we ran whitewoods (washer/ dishwasher, etc) either during periods of high solar generation or overnight cheap rate depending on the weather. My chargeable usage has more than doubled in this year.

If you're on the Tesla plan - have you found the same?

Thanks for reading

Alan
 

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[/QUOTE] hi Alan
I am having exactly the same issue. My import is 11p because i don’t have a Tesla car and export is 11 p, no standing charge. My usage has gone up and it simply doesn’t make sense. I’m generating 11Kw a day by solar but my Tesla powerwall consumes 10 kw but my house uses only 5kw. It’s like 4 kw is going to Tesla powerwall for free
 
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