240 likes | 328 Views
The infuriating inconsistency of network electricity carbon intensity. Andrew Peacock Heriot Watt University. CO 2 Emissions Saving Methodology. World Resources Institute recommend that the grid electricity emission reduction factor should be calculated thus:. ER baseline = ω.BM + (1-ω).OM.
E N D
The infuriating inconsistency of network electricity carbon intensity Andrew Peacock Heriot Watt University
CO2 Emissions Saving Methodology World Resources Institute recommend that the grid electricity emission reduction factor should be calculated thus: ERbaseline = ω.BM + (1-ω).OM
CO2 Emissions Saving Methodology World Resources Institute recommend that the grid electricity emission reduction factor should be calculated thus: ERbaseline = ω.BM + (1-ω).OM
BM – Build Margin emission rate Assumes that the electricity reduction measure will reduce the need for future capacity A proportion of the reduction is then assigned to the deferment of this added capacity FIRST CONFUSION What new plant is planned in the UK?
Installed Plant in the UK (2007/8) Source: National Grid 7 year statement, 2007
Planned new plant (2013/14) Source: National Grid 7 year statement, 2007
Planned new plant (to 2020) However Coal – 14.2 GW of new coal plant is in various stages of development Will coal be resurgent? Principal uncertainty – 3rd Revision of the EU Emission trading scheme DEFRA Guidance 2007 – Build Margin Rate = 0.43kgCO2/kWh (Assumed for a CCGT Plant) Build Margin emission rate for; Coal (45% efficient plant) 0.776kgCO2/kWh CCGT (50% efficient plant) 0.412kgCO2/kWh
CO2 Emissions Saving Methodology World Resources Institute recommend that the grid electricity emission reduction factor should be calculated thus: ERbaseline = ω.BM + (1-ω).OM
CO2 Emissions Saving Methodology World Resources Institute recommend that the grid electricity emission reduction factor should be calculated thus: ERbaseline = ω.BM + (1-ω).OM
Operating Margin Emission Factor Assumes that the electricity reduction measure will reduce demand SECOND CONFUSION What carbon intensity do we assign to the negawatts?
System Average Carbon Intensity DEFRA Guidance – 5 Year rolling average – 0.523kgCO2/kWh
Not all plant will respond If we exclude nuclear – approximate “load following” 5 year rolling average = 0.671kgCO2/kWh
CO2 Emissions Saving Methodology World Resources Institute recommend that the grid electricity emission reduction factor should be calculated thus: ERbaseline = ω.BM + (1-ω).OM
CO2 Emissions Saving Methodology World Resources Institute recommend that the grid electricity emission reduction factor should be calculated thus: ERbaseline = ω.BM + (1-ω).OM
Third Confusion Weighting factor, w No effect on system capacity Approx 2.9GW of maximum system peak demand is due to domestic lighting. This will fall to approx 1.45GW with banning of incandescent bulbs in 2010
Effect on savings from CFL Lighting and Solar-PV Using DEFRA Guidance
Effect on savings from CFL Lighting and Solar-PV Spread of possible BM and OM figures Can be 53% higher Can be 76% higher
Conclusions Deriving a simple number for Carbon intensity of network electricity that suits all technologies is impractical and will mislead The recognised international metric discussed here could be employed One approach might be to assign factors to technologies based on this standard procedure This has been a talk largely about the present – the future is more difficult still
Further Complication Time variant nature of carbon intensity Wednesday 26th January 2005
Time variant nature of carbon intensity Wednesday 26th January 2005
Time variant nature of carbon intensity Demand side response to reduce gradient change has the capacity to alter operating protocols that could yield reductions in CO2 intensity of network electricity