Earth Notes: GB Grid Intensity YELLOW*

*WARNING: cannot obtain current data so this is partly based on predictions from historical data (for 6:XX GMT).

 
Grid is probably OK; but you could still avoid CO2 emissions by postponing running big appliances such as dishwashers or washing machines
 

You might have saved as much as 48% carbon emissions by choosing the best time to run your washing and other major loads.

Latest data is from Mon Oct 22 02:00:00 UTC 2018. 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This free service is in BETA and may be unavailable or withdrawn at any time and is provided "as-is" with no warranties of any kind.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 (eg here) 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!

Recent effective carbon intensity for a domestic user at this time of day was 183gCO2/kWh including transmission and distribution losses of 7%.

Latest available grid generation carbon intensity (ignoring transmission/distribution losses) is approximately 110gCO2/kWh at Mon Oct 22 02:00:00 UTC 2018 over 21977MW of generation, with a rolling average over 24h of 171gCO2/kWh.

Minimum grid generation carbon intensity (ignoring transmission/distribution losses) was approximately 109gCO2/kWh at Sun Oct 21 23:25:00 UTC 2018.

Maximum grid generation carbon intensity (ignoring transmission/distribution losses) was approximately 208gCO2/kWh at Sun Oct 21 16:10:00 UTC 2018.

Average/mean grid generation carbon intensity (ignoring transmission/distribution losses) was approximately 171gCO2/kWh over the sample data set, with an effective end-user intensity including transmission and distribution losses of 183gCO2/kWh.

Last available historical mean GMT hourly generation intensity gCO2/kWh (average=171); *now (=110)
00010203040506*0708091011121314151617181920212223
  • 112
  • 111
  • 173
  • 169
  • 168
  • 175
  • 182
  • 185
  • 189
  • 192
  • 184
  • 178
  • 172
  • 173
  • 184
  • 197
  • 206
  • 205
  • 200
  • 193
  • 175
  • 153
  • 129
  • 111
Mean GMT hourly generation GW (all, zero-carbon)
  • 23
  • 15
  • 22
  • 14
  • 22
  • 10
  • 21
  • 10
  • 22
  • 11
  • 23
  • 11
  • 24
  • 11
  • 26
  • 11
  • 27
  • 12
  • 27
  • 11
  • 27
  • 12
  • 26
  • 12
  • 26
  • 12
  • 26
  • 12
  • 27
  • 12
  • 30
  • 12
  • 32
  • 13
  • 34
  • 13
  • 34
  • 13
  • 32
  • 14
  • 30
  • 14
  • 27
  • 14
  • 24
  • 14
  • 23
  • 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.

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 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=0.7033 CCGT=0.8818 INTEW=0.3766 INTFR=0.7162 INTIRL=0.5117 INTNED=0.7710 NPSHYD=0.5828 NUCLEAR=-0.0848 OTHER=-0.3386 WIND=-0.5723.

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
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 Mon Oct 22 06:51:28 UTC 2018; generation time 25839ms.

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]