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Comparing Electricity price plans -- there's not as much in it as you think

Fredneck

Member
Nov 8, 2019
478
293
Pennsylvania
You seem to be saying "it would just be a drop in the ocean so it's not worth doing".
I'm not arguing for PowerWall (I won't be buying one any time soon). But I think it's pretty well understood that we need to even out the load to fully get rid of Coal and Gas. That requires storing either electricity or energy that can directly and quickly generate electricity.
My understanding of those giant batteries is that they pay for themselves in ridiculously short timeframes (for the size of the investment).

Someone in another forum who lives in Australia and keeps on top of these things has listed significant data for the very large power wall Musk installed for line regulation in South Australia about two years ago. The cost was $66 million and I believe it has already recouped that or nearly that much by reducing the cost of peak power and preventing blackouts. There was a blackout during a record heat wave so now they are increasing capacity of the battery by 50%. Money well spent.
 
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im85288

Member
Aug 31, 2019
86
72
Newcastle
The question I was asking, which I am pretty sure of the answer: does the PowerWall make economic sense, and the answer seems to be a resounding no.

Your probably right about this, but going from my own personal experience where I missed the deadline for the Feed In Tariff it would have meant any extra solar I generated was sent back to the Grid free of charge. At least with having the powerwall I am seeing that energy going into the powerwall and subsequently used when solar generation stops. For me personally that alone justify's having battery storage in some shape or form.
 

rotor2k

Member
Sep 16, 2019
524
293
London
Your probably right about this, but going from my own personal experience where I missed the deadline for the Feed In Tariff it would have meant any extra solar I generated was sent back to the Grid free of charge. At least with having the powerwall I am seeing that energy going into the powerwall and subsequently used when solar generation stops. For me personally that alone justify's having battery storage in some shape or form.
Isn’t there a new law in 2020 where every power company has to offer a feed in tariff? If so then your current problem may only be temporary.
 

Glan gluaisne

Supporting Member
Supporting Member
Sep 11, 2019
2,782
2,912
UK
Isn’t there a new law in 2020 where every power company has to offer a feed in tariff? If so then your current problem may only be temporary.

No, the Feed in Tariff incentive is well and truly dead and buried. Unfortunately, when they killed off the FiT they also accidentally killed off the export payment scheme, something that has meant that anyone fitting a new PV system doesn't get paid anything for the energy they export to the grid.

Before the FiT came along, there was a system for paying small generators for the electricity they exported to the grid, more or less at the average wholesale price. When the FiT came along, they swept that export payment up into the FiT scheme, so that micro generators received two payments every quarter, a FiT subsidy based on all the electricity they generated, plus an export payment for the electricity they exported to the grid. Both payments were shown separately, with the export payment being the same as before, about the average wholesale price for each unit that was either metered as being exported, or for those without an export meter, it was deemed to be 50% of their metered generation.

Taking our system as an example, we get paid FiT for every kWh of electricity we generate, plus we get another ~5.5p/kWh for 50% of the electricity we generate, as that's assumed to be exported to the grid. In reality we export more than 50% of our generation, so we still give the grid some free electricity.

What's being re-introduced is the export payment, so that people will be paid roughly the wholesale price for any electricity they generate, bringing them into line with other electricity generators.
 

im85288

Member
Aug 31, 2019
86
72
Newcastle
Yes exactly there will be what's now called the SEG (Smart Export Guarantee) where powere companies can decide to pay you whatever they choose for energy exported back to the grid...which will be better than nothing at all and of course will create competition between the energy suppliers to get your custom. Indications seem to be that the amount they will offer at least at the very start will not be much at all, but yes I am looking forward to that.

Octopus have something similar already known as Octopus Output where they pay 5.5p per kwh for every unit....but unfortunately I cannot use that tariff in combination with Octopus GO.

Anyway 2020 will for sure bring more competition to the market which can only be a good thing.
 

kuruma

Member
Aug 29, 2019
315
144
Northeast
we have Gateway 2 with our PW2. I may be missing some of the detail in your comments Jeremy because you're obviously much more of a techie than me, but with the Gateway, we can control how much of our PW is dedicated to powering the house if there's a powercut.

There is absolutely no lag when the power dies. The PW switch is instantaneous and interrupts nothing that depends on a constant power connection.
 
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Adopado

Active Member
Aug 19, 2019
4,533
3,422
Scotland
we have Gateway 2 with our PW2. I may be missing some of the detail in your comments Jeremy because you're obviously much more of a techie than me, but with the Gateway, we can control how much of our PW is dedicated to powering the house if there's a powercut.

There is absolutely no lag when the power dies. The PW switch is instantaneous and interrupts nothing that depends on a constant power connection.

That's interesting to note that there's effectively no lag in the switching. The Fullycharged video of Robert Llewelyn's new setup with the Gateway and Powerwall had quite a long delay when they cut the external power ... I presume there was some other issue affecting the changeover isolating the Powerwall from the grid.
 

MostlyHappy

Member
Jan 11, 2020
17
5
UK
This is a really useful thread.
I have only just got my 7kW charger so to soon to say, but as I regularly do 200 miles in a day, economy 7 tariff seems to make more sense than a slightly cheaper economy 5 tariff if I charge at 25-30 miles per hour. Was looking at the Scottish power EV tariff at 4.78p from 0000-0500 compared to Economy 7 at 7p off peak 0030-0730.
 

MurtzD

Member
Jun 12, 2019
18
0
Leicester
I haven't read through the thread.. but has anyone seen the EDF EV tariff? 8p for evenings and weekends, I think it works out much better than the Octopus Go tariff..
 

Mark_T

Active Member
Nov 1, 2017
1,305
1,145
UK
I haven't read through the thread.. but has anyone seen the EDF EV tariff? 8p for evenings and weekends, I think it works out much better than the Octopus Go tariff..

Entirely depends on your usage pattern.

I've been comparing EDF, Octopus Go/Agile and Bulb for about 14 weeks now and for my usage pattern EDF worked out about £1 a week cheaper than Go, but only as long as I didn't do any significant car charging during the cheap 4 hours a night period with Go...

EDF suits those who are not at home during the days so minimal usage of power before the evening cheap rate cuts in, and those that can't fit their charging needs within the 4 hour period that Go offers...

The catch is that if you do have any significant usage of power during the day Mon - Fri, and you can limit your charging to the 4 hours a night, it tends to eat up most of the savings again Go due to EDF having a higher daily rate and higher night rate.

To give that a bit more context, I don't need to charge every day, but any day I did charge overnight within the 4 hours I would be about £0.50/day more expensive on EDF, at the weekends with the lower EDF rate all the time, as long as I didn't charge I'd save about £1.20/day. So a week where I charged each night M-F and didn't charge at the weekend I'd see no difference between the tariffs. If I charged at the weekend as well then Go would be cheaper for the week as a whole...
 
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KennethS

Supporting Member
Supporting Member
May 3, 2019
563
393
UK
Entirely depends on your usage pattern.

I've been comparing EDF, Octopus Go/Agile and Bulb for about 14 weeks now and for my usage pattern EDF worked out about £1 a week cheaper than Go, but only as long as I didn't do any significant car charging during the cheap 4 hours a night period with Go...

EDF suits those who are not at home during the days so minimal usage of power before the evening cheap rate cuts in, and those that can't fit their charging needs within the 4 hour period that Go offers...

The catch is that if you do have any significant usage of power during the day Mon - Fri, and you can limit your charging to the 4 hours a night, it tends to eat up most of the savings again Go due to EDF having a higher daily rate and higher night rate.

To give that a bit more context, I don't need to charge every day, but any day I did charge overnight within the 4 hours I would be about £0.50/day more expensive on EDF, at the weekends with the lower EDF rate all the time, as long as I didn't charge I'd save about £1.20/day. So a week where I charged each night M-F and didn't charge at the weekend I'd see no difference between the tariffs. If I charged at the weekend as well then Go would be cheaper for the week as a whole...
This is all so confounding trying to select my next energy supplier. Currently with OVO Energy and have SMETS2 meters, and my fixed tariff is coming to an end, so time to shop around. We are a fairly high energy usage home and low mileage drivers. Obviously I can time the car charging as and when it is cheapest, but most other electric usage is hard to time shift. It seems any TOU discount arrangements get more than offset by higher peak rate costs, over going with just flat rate pricing. So my back of the envelope calculations never seem to find much in it. I hate to lock in another 12+ month deal and find later I missed something obvious (although paying early termination fees is always an option).
 

Glan gluaisne

Supporting Member
Supporting Member
Sep 11, 2019
2,782
2,912
UK
Entirely depends on your usage pattern.

Exactly.

Right now, for us, the standard Bulb E7 rate is still the cheapest overall, but that may change as these newer tariffs evolve.

My approach has been to shift as much load to the overnight period as possible (as all the variable rate tariffs are cheaper at night) and then pick the tariff that best fits the pattern of use we can realistically achieve.

To some extent there's not a lot of merit in spending too much time on this, though, as we're paying less than £50 a month for electricity, and that includes heating the house, all our hot water, cooking, charging the car etc, and right now it looks like our direct debit might be a bit too high, as we're still over £100 in credit, with only another two or three cold months to go.
 

Mark_T

Active Member
Nov 1, 2017
1,305
1,145
UK
We are a fairly high energy usage home and low mileage drivers.

Given you are already on SMETS2, do you have your 30 min usage data for the past few months?

If you do then it isn't all that hard to model out the options.

If you don't then yes, it is hard to make a choice when you don't have the information to base it on.

A lot does depend on what percentage of your electricity is used between 16:00-19:00 each day so if you can work that out it will help to rule in or out things like Octopus Agile and the Bulb smart tariff...
 

KennethS

Supporting Member
Supporting Member
May 3, 2019
563
393
UK
Given you are already on SMETS2, do you have your 30 min usage data for the past few months?

If you do then it isn't all that hard to model out the options.

If you don't then yes, it is hard to make a choice when you don't have the information to base it on.

A lot does depend on what percentage of your electricity is used between 16:00-19:00 each day so if you can work that out it will help to rule in or out things like Octopus Agile and the Bulb smart tariff...
I have had the "smart" meters since July so I guess I need to do some real computations and not just look at crude big picture estimations.
 
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Mark_T

Active Member
Nov 1, 2017
1,305
1,145
UK
I have had the "smart" meters since July so I guess I need to do some real computations and not just look at crude big picture estimations.

So many subtleties in the tariffs that you really can't beat a detailed analysis using your own usage data.

Once you do that you'll know the best tariff to use without changing your routine, then you can look at the the possibilities to improve further with small changes.

For us Agile was the cheapest even with no changes, but now we are using it, we have made a few small alterations in our usage and increased the savings a bit further.
 
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