Earth Notes: GB Grid Intensity GREEN

 
 
Grid is good; you might run major loads such as your dishwasher and/or washing machine now to minimise CO2 emissions

You might have saved as much as 50% carbon emissions by choosing the best time to run your washing and other major loads.

Latest data is from Wed Feb 20 04:25:00 UTC 2019. 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.

This free service is in BETA and may be unavailable or withdrawn at any time and is provided "as-is" with no warranties of any kind.

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 if 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 149gCO2/kWh including transmission and distribution losses of 7%.

Latest available grid generation carbon intensity (ignoring transmission/distribution losses) is approximately 139gCO2/kWh at Wed Feb 20 04:25:00 UTC 2019 over 25435MW of generation, with a rolling average over 24h of 218gCO2/kWh.

Minimum grid generation carbon intensity (ignoring transmission/distribution losses) was approximately 138gCO2/kWh at Wed Feb 20 04:05:00 UTC 2019.

Maximum grid generation carbon intensity (ignoring transmission/distribution losses) was approximately 273gCO2/kWh at Tue Feb 19 16:45:00 UTC 2019.

Average/mean grid generation carbon intensity (ignoring transmission/distribution losses) was approximately 218gCO2/kWh over the sample data set, with an effective end-user intensity including transmission and distribution losses of 233gCO2/kWh.

Recent mean GMT hourly generation intensity gCO2/kWh (average=218); *now (=139)
050607080910111213141516171819202122230001020304*
  • 171
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  • 179
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  • 148
Mean GMT hourly generation GW (all, zero-carbon)
  • 27
  • 14
  • 31
  • 13
  • 36
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  • 12
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  • 36
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  • 13
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  • 14
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  • 15
  • 39
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  • 35
  • 16
  • 31
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  • 27
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  • 15

Hours that are basically green, but in which there is draw-down from grid-connected storage with its attendant energy losses and also suggesting that little or no excess non-dispatchable generation is available, ie that are marginally green, are shaded olive.

Current/latest fuel mix at Wed Feb 20 04:25:00 UTC 2019: BIOMASS@1148MW CCGT@5769MW COAL@0MW INTEW@504MW INTFR@1499MW INTIRL@99MW INTNED@537MW INTNEM@690MW NPSHYD@490MW NUCLEAR@5964MW OCGT@0MW OIL@0MW OTHER@69MW PS@0MW WIND@8666MW.

Generation by fuel category (may overlap):

fossil @ 23%
5769MW [CCGT, COAL, OCGT, OIL]
import @ 13%
3329MW [INTEW, INTFR, INTIRL, INTNED, INTNEM]
nuclear @ 29%
7463MW [INTFR, NUCLEAR]
renewable @ 41%
10304MW [BIOMASS, NPSHYD, WIND]
storage @ 0%
0MW [PS]
zero-carbon @ 59%
15120MW [NPSHYD, NUCLEAR, WIND]

Overall generation intensity (kgCO2/kWh) computed using the following fuel intensities (other fuels/sources are ignored): BIOMASS=0.3 CCGT=0.36 COAL=0.91 INTEW=0.45 INTFR=0.09 INTIRL=0.45 INTNED=0.55 INTNEM=0.55 NPSHYD=0.0 NUCLEAR=0.0 OCGT=0.48 OIL=0.61 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=0.9199 CCGT=0.9763 COAL=0.9612 INTEW=-0.3287 INTFR=0.6167 INTIRL=-0.0163 INTNED=0.7923 INTNEM=0.7577 NPSHYD=0.8296 NUCLEAR=0.0572 OTHER=0.2419 WIND=-0.8081.

Key to fuel codes:

BIOMASS
Biomass
CCGT
Combined-Cycle Gas Turbine
INTEW
East-West (Irish) Interconnector
INTFR
French Interconnector
INTIRL
Irish (Moyle) Interconnector
INTNED
Netherlands Interconnector
INTNEM
Nemo (Belgian) Interconnector
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.

This page updated at Wed Feb 20 04:31:06 UTC 2019; generation time 5166ms.

See also:

Poll every 10 minutes for 404 HTTP status code (404 means green, 200 means not green, anything else is 'unknown' status due to server/network/other problems) for automated systems:

(Please email me if you use this mechanism, to be alerted to changes.)

See code on GitHub.

This free service may be unavailable or withdrawn at any time and is provided "as-is" with no warranties of any kind.
Some data used to generate this page is licensed from ELEXON.
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Copyright © Damon Hart-Davis 2010--2018. [home]