savingSessions: energy analysis

Author

Ben Anderson (@dataknut)

Published

January 25, 2023

1 No longer updated

See the integrated electricity demand and twitter report instead.

2 Introduction

UK ‘demand flexibility service’ DFS experiments/trials/‘live’ events by NG-ESO and retailers such as @OctopusEnergy

  • DFS began on 1 November 2022.
  • The service will run until March 2023.

Relevant media articles:

Q: Is there a noticeable ‘dip’ in demand?

(Can we even tell?)

3 Code setup

Part of https://github.com/dataknut/savingSessions

4 Getting data

Use the half-hourly NG-ESO ‘generation mix’ data as a reasonable proxy for ‘demand’.

Should probably use the demand data instead as it includes embedded wind & solar.

Variables of interest:

  • GENERATION is in MW. It has some exclusions, its just an indicator.
  • CARBON_INTENSITY is in g CO2/kWh - we’d expect this to be high during DFS events (as we’re trying to avoid the use of high carbon & expensive generation?)

5 Analysis

Simple comparison of the ‘demand response session’ day half-hourly demand with the mean half-hourly demand for the previous n days.

All sorts of caveats apply:

  • not all of these sessions were national ‘live’ events, some were trials by a single retailer (Octopus)
  • we may not be comparing like with like (cold vs warm, weekday vs weekend etc)
  • we can’t tell from this analysis what demand would have looked like without the demand response intervention. That would require all the retailers to aggregate the ‘savings’ they estimate… or a randomised control trial

5.1 Session 1 (Octopus: Tue 15 Nov 2022 17:00)

  • 2022-11-15 17:00:00 to
  • 2022-11-15 18:00:00

(Not all retailers may have taken part in this one)

According to https://energycentral.com/news/octopus-energy-provide-108mw-grid-flexibility-first-%E2%80%98saving-session%E2%80%99:

“Over 200,000 households reduced their energy demand by 108MW collectively, the same as a gas power station can generate in an hour. If replicated by all UK energy suppliers, this would be over 1GW.”

But https://www.current-news.co.uk/news/octopus-energy-customers-provide-108mw-of-flexibility-during-first-saving-session quotes Octopus as actually saying:

“if the program was scaled to all electric smart meter customers with all supplier[s] in Great Britain, it could create over 1GW of flexible energy load”

The following plot compares the energy use during the DFS event with mean energy use over the last 10 days.

MW comparisons

hms

Comparison mean

Saving session

MW_diff

pc_diff

17:00:00

40,226.7

42,925.0

2,698.3

6.7

17:30:00

40,238.7

42,736.0

2,497.3

6.2

Confounding factors:

  • recent temperature trends
  • recent holidays
  • etc

Note that the comparison plot/table shows the difference between the DFS event day and the previous similar days. This does not show what the event day energy use would have been in the absence of the intervention - we’d need a randomised control on the day for that (or a sophisticated demand model as the counterfactual).

Octopus customers’ 108 MW was 0.252 % of mean GB generation (42.925 GW) over the hour of the session (see NG-ESO data above).

108 MW over 200,000 customers is 5.4^{-4} MW per household or, more sensibly, 0.54 kW per household. A pretty reasonable reduction.

But if 200,000 produced a 108 MW power reduction (0.54 kW per household ), the 1 GW estimate implies we only have 1,851,852 GB households with a smart meter. Really? Or did they mean all suppliers taking part in the scheme?

Anyway, the latest data has 14 million domestic eletricity smart meters as of Q1 2022 - 45% of all domestic meters.

So:

  • If all ~28 million households in the UK did this it would be 1.512^{7} kW. That’s 15.12 GW…
  • If we reduce ambition a bit and assume that only the 14 million domestic GB customers with a smart meter as of Q2 2022 did this then that would provide 7.56 GW. Which would be 17.61 % of generation. Not bad aye?

The trouble is… these are octopus customers self-selecting into a trial. You just have to read the tweets to see that there are households with installed batteries, pausable heat pumps in well-insulated homes and EV V2G. At what point will we all be similarly equipped?

And just to keep in mind the carbon context:

Figure 1: Comparison of carbon intensity

5.2 Session 2 (Octopus: Tue 22 Nov 2022 17:30)

  • 2022-11-22 17:30:00 to
  • 2022-11-22 18:30:00

(Not all retailers may have taken part in this one)

The same caveats about the comparisons apply here…

MW comparisons

hms

Comparison mean

Saving session

MW_diff

pc_diff

17:30:00

41,706.9

41,355.0

-351.9

-0.8

18:00:00

41,339.7

40,784.0

-555.7

-1.3

And just to keep in mind the carbon context:

Figure 2: Comparison of carbon intensity

5.3 Session 3 (Octopus: Wed 30 Nov 2022 17:30)

  • 2022-12-01 17:00:00 to
  • 2022-12-01 18:00:00

(Not all retailers may have taken part in this one)

The same caveats about the comparisons apply here…

MW comparisons

hms

Comparison mean

Saving session

MW_diff

pc_diff

17:30:00

42,687.9

41,488.0

-1,199.9

-2.8

18:00:00

42,102.9

41,011.0

-1,091.9

-2.6

And just to keep in mind the carbon context:

Figure 3: Comparison of carbon intensity

5.4 Session 4 (Octopus: Thu 01 Dec 2022 17:00)

  • 2022-12-01 17:00:00 to
  • 2022-12-01 18:00:00

(Not all retailers may have taken part in this one)

The same caveats about the comparisons apply here…

MW comparisons

hms

Comparison mean

Saving session

MW_diff

pc_diff

17:00:00

42,751.9

42,065.0

-686.9

-1.6

17:30:00

42,693.6

42,194.0

-499.6

-1.2

And just to keep in mind the carbon context:

Figure 4: Comparison of carbon intensity

5.5 Session 5 (Octopus: Mon 12 Dec 2022 17:00)

  • 2022-12-12 17:00:00 to
  • 2022-12-12 18:00:00

(Not all retailers may have taken part in this one)

The same caveats about the comparisons apply here…

MW comparisons

hms

Comparison mean

Saving session

MW_diff

pc_diff

17:00:00

43,849.1

47,821.0

3,971.9

9.1

17:30:00

43,871.3

48,470.0

4,598.7

10.5

And just to keep in mind the carbon context:

Figure 5: Comparison of carbon intensity

5.6 Session 6 (Octopus: Thu 19 Jan 2023 09:00)

  • 2023-01-19 09:00:00 to
  • 2023-01-19 10:00:00

(Not all retailers may have taken part in this one)

The same caveats about the comparisons apply here…

MW comparisons

hms

Comparison mean

Saving session

MW_diff

pc_diff

09:00:00

39,729.3

45,823.0

6,093.7

15.3

09:30:00

40,463.5

46,739.0

6,275.5

15.5

And just to keep in mind the carbon context:

Figure 6: Comparison of carbon intensity

5.7 Session 7 (NG-ESO ‘live’: Mon 23 Jan 2023 17:00)

This was a more generalised call for DFS:

  • 2023-01-23 17:00:00 to
  • 2023-01-23 18:00:00

The same caveats about the comparisons apply here…

MW comparisons

hms

Comparison mean

Saving session

MW_diff

pc_diff

17:00:00

43,930.7

46,086.0

2,155.3

4.9

17:30:00

44,034.9

45,684.0

1,649.1

3.7

And just to keep in mind the carbon context:

Figure 7: Comparison of carbon intensity

5.8 Session 8 (NG-ESO ‘live’: Tue 24 Jan 2023 16:30)

This was another generalised call for DFS:

  • 2023-01-24 16:30:00 to
  • 2023-01-24 18:00:00

The same caveats about the comparisons apply here…

Also this ecent followed very soon after the last one so this will affect the comparison ‘baseline’ (previous n days).

MW comparisons

hms

Comparison mean

Saving session

MW_diff

pc_diff

16:30:00

43,409.2

44,975.0

1,565.8

3.6

17:00:00

44,395.9

45,275.0

879.1

2.0

17:30:00

44,466.2

44,814.0

347.8

0.8

And just to keep in mind the carbon context:

Figure 8: Comparison of carbon intensity

6 Future work

  • more trial days
  • use 5 days before/after as comparators? Confounded by events close together…