Earth Notes: GB Grid Intensity RED

Grid carbon intensity is high; please do not run big appliances such as a dishwasher or washing machine now if you can postpone
 
 

You might have saved as much as 52% carbon emissions by choosing the best time to run your washing and other major loads.

Latest data is from Sat May 21 15:05:00 UTC 2022. This page should be updated every few minutes: use your browser's refresh/reload button if you need to check again.

Follow this grid status on Twitter @EarthOrgUK.

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This page shows the current "carbon intensity" of the GB National Grid (ie the England/Scotland/Wales portions of the UK electricity grid) as a simple traffic-light indicator. Carbon intensity is a measure of how much greenhouse gas (especially CO2 or carbon dioxide) is emitted to generate a fixed amount of electricity.

Anything other than a GREEN light suggests that you should consider deferring heavy loads (eg starting a dishwasher or washing-machine at home) because the carbon intensity is relatively high, or because of other factors. Avoiding running major appliances such as washing/heating/cooking during RED times will save CO2 emissions.

You should still conserve first: don't run things that don't need to be run at all, don't leave things on that can be turned off at the wall, run full loads in your washing machine and dishwasher, etc, etc, before worrying about carbon intensity.

Planning ahead: note that in the UK/GB peak demand for electricity will usually be 4pm to 9pm especially on week days in winter (and a lesser peak around 9am/10am), and peak carbon intensity is often around peak demand, so try to avoid big loads then; if possible run loads such as your dishwasher and washing machine overnight, eg on a delay timer or just as you go to bed, or when you have local microgeneration that can cover much/all of the load.

There is argument about whether this marginal cost calculation reflects reality, ie in practice is there simply a gas turbine somewhere that gets spun up a little if you demand extra power. There is much less argument about the value of lowering demand generally, and about lowering peak demand on various parts of the infrastructure.

Shifting loads to the night when energy is going into grid-scale storage such as pumped hydro, avoids pulling it out when you would otherwise run/dispatch the load, and thus saves round-trip losses of ~25% for that load.

Technical Stuff

You don't need to understand the numbers below, but some people like to see them!

Effective grid carbon intensity for a domestic user is currently 232gCO2/kWh including transmission and distribution losses of 7%.

Latest available grid generation carbon intensity (ignoring transmission/distribution losses) is approximately 217gCO2/kWh at Sat May 21 15:05:00 UTC 2022 over 23352MW of generation, with a rolling average over 24h of 179gCO2/kWh.

Minimum grid generation carbon intensity (ignoring transmission/distribution losses) was approximately 109gCO2/kWh at Sat May 21 02:00:00 UTC 2022.

Maximum grid generation carbon intensity (ignoring transmission/distribution losses) was approximately 225gCO2/kWh at Fri May 20 16:00:00 UTC 2022.

Average/mean grid generation carbon intensity (ignoring transmission/distribution losses) was approximately 179gCO2/kWh over the sample data set, with an effective end-user intensity including transmission and distribution losses of 192gCO2/kWh.

Recent mean GMT hourly generation intensity gCO2/kWh (average=179); *now (=217)
161718192021222300010203040506070809101112131415*
  • 224
  • 220
  • 215
  • 202
  • 195
  • 179
  • 143
  • 127
  • 120
  • 112
  • 112
  • 124
  • 135
  • 154
  • 190
  • 212
  • 212
  • 207
  • 207
  • 208
  • 193
  • 191
  • 198
  • 219
Mean GMT hourly generation GW (all, zero-carbon)
  • 32
  • 13
  • 33
  • 14
  • 33
  • 14
  • 32
  • 15
  • 31
  • 15
  • 29
  • 15
  • 26
  • 16
  • 24
  • 16
  • 23
  • 16
  • 23
  • 16
  • 22
  • 16
  • 22
  • 15
  • 22
  • 14
  • 22
  • 13
  • 24
  • 12
  • 25
  • 11
  • 25
  • 11
  • 25
  • 11
  • 24
  • 11
  • 24
  • 11
  • 23
  • 11
  • 22
  • 11
  • 22
  • 11
  • 29
  • 12

Current/latest fuel mix at Sat May 21 15:05:00 UTC 2022: BIOMASS@142MW CCGT@12127MW COAL@0MW INTELEC@0MW INTEW@42MW INTFR@0MW INTIFA2@0MW INTIRL@235MW INTNED@0MW INTNEM@0MW INTNSL@0MW NPSHYD@356MW NUCLEAR@4926MW OCGT@0MW OIL@0MW OTHER@190MW PS@413MW WIND@4921MW.

Current draw-down from storage is 413MW.

Generation by fuel category (may overlap):

fossil @ 52%
12127MW [CCGT, COAL, OCGT, OIL]
import @ 1%
277MW [INTELEC, INTEW, INTFR, INTIFA2, INTIRL, INTNED, INTNEM, INTNSL]
nuclear @ 21%
4926MW [INTELEC, INTFR, INTIFA2, NUCLEAR]
renewable @ 23%
5419MW [BIOMASS, NPSHYD, WIND]
storage @ 2%
413MW [PS]
zero-carbon @ 44%
10203MW [NPSHYD, NUCLEAR, WIND]

Overall generation intensity (kgCO2/kWh) computed using the following fuel year-2022 intensities (other fuels/sources are ignored): BIOMASS=0.12 CCGT=0.394 COAL=0.937 INTELEC=0.053 INTEW=0.458 INTFR=0.053 INTIFA2=0.053 INTIRL=0.458 INTNED=0.474 INTNEM=0.179 INTNSL=0.016 NPSHYD=0.0 NUCLEAR=0.0 OCGT=0.651 OIL=0.935 OTHER=0.3 WIND=0.0.

Rolling correlation of fuel use against grid intensity (-ve implies that this fuel reduces grid intensity for non-callable sources): BIOMASS=0.1049 CCGT=0.8199 INTEW=0.0456 INTIRL=0.3438 INTNED=0.4433 INTNEM=0.2541 INTNSL=0.2580 NPSHYD=0.8532 NUCLEAR=0.4436 OCGT=-0.1374 OTHER=0.3262 WIND=-0.7840.

Key to fuel codes:

CCGT
Combined-Cycle Gas Turbine
INTELEC
INTELEC (French) Interconnector
INTEW
East-West (Irish) Interconnector
INTFR
IFA1 French Interconnector
INTIFA2
IFA2 (French) Interconnector
INTIRL
Irish (Moyle) Interconnector
INTNED
Netherlands Interconnector
INTNEM
Nemo (Belgian) Interconnector
INTNSL
North Sea Link (Norway)
NPSHYD
Non-Pumped-Storage Hydro
OCGT
Open-Cycle Gas Turbine
OTHER
Other
PS
Pumped Storage Hydro

Methodology

This estimates the carbon intensity of generation connected to the National Grid GB (Great Britain) high-voltage transmission system, ignoring (pumped) storage and exports but including imports via interconnectors. This excludes 'embedded' generation, eg connected directly to the distribution system, such as small diesels, domestic microgeneration and a significant chunk of wind power, all of which also benefits from reduced transmission/distribution losses, so actual intensity may be somewhat different to (and probably lower than) that reported. However the emissions cost of each marginal/conserved kWh is probably accurately reflected.

(Colours are wrt the last 24h of data.)

This page updated at Sat May 21 15:11:08 UTC 2022; generation time 6507ms.

See also:

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See code on GitHub.

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