Three possible pathways to an all-electric, low-carbon future
Professor Matthew Leach
Director of the Centre for Environmental Strategy at University of Surrey http://www.surrey.ac.uk/ces
Post date: Wednesday, 22nd February 2012
The increasingly common accepted wisdom of an 'electrified' future brings new risks and uncertainties.
If they are focused too strongly on increasing the role of electricity, efforts at meeting the tough emissions targets in the government's Low Carbon Transition Plan will be doubly exposed to all the implementation issues around low carbon electricity generation technologies, questions about the financing of infrastructure investment, as well as uncertainties for the new electricity market reforms.
In practice this approach would mean electrification of space heating for buildings (primarily through the use of heat pumps), road transport through the use of electric and plug-in hybrid cars, and a power sector 'decarbonising' rapidly through renewables (largely offshore wind), newbuild nuclear and possibly carbon capture and storage. This inevitably means problems for consumers. The success of heat pumps for homes will depend upon very high adoption levels for insulation and other domestic energy efficiency measures - all of which are subject to strong practical barriers: for retrofit into the enormous stock of Victorian terrace housing for example, air source heat pump heat exchangers would have to be sited in small but precious backyards.
The future of heating is in practice likely to be – and should be – more diverse than recent studies assume. Electric heating will have a role, but there should be roles too for further combined heat and power, district heating networks, bioenergy, biogas and truly zero-heating new build. Only diversity can offer a robust solution for long-term and sustainable change.
Work at the Centre for Environmental Strategy at the University of Surrey in partnership with a consortium of other UK universities has mapped the likely implications of taking different pathways to a low-carbon economy. We looked at three pathways to 2050 - a market-led pathway or 'Market Rules', a government-led pathway, 'Central Coordination', and a civil society-led pathway, 'Thousand Flowers'. The studies predict the impacts from each approach in terms of energy efficiency, for example, in terms of energy demand for space and water heating in domestic properties, demand is reduced by 31%, 33% and 37% for Market Rules, Central Coordination and Thousand Flowers respectively, despite a 30% growth in the number of households.
Overall, however, all three pathways present considerable challenges. The results for the year 2050 show that peak levels of demand can be very high: up to 83 GW in Market Rules and up to 66 GW in Central Coordination but only 38 GW in Thousand Flowers, compared to 57 GW so far this winter. In all three pathways, a significant amount of generating plant has to operate at very low capacity factors (less than 10%): 32 GW in Market Rules, 26 GW in Central Coordination and 17 GW in Thousand Flowers, as fossil-fuelled power stations are held in reserve to back-up intermittent renewable generation. All three pathways result in significant electricity surpluses –arising from high wind power generation happening to occur at times of low demand, peaking at 19 GW in Market Rules, 15 GW in Central Coordination and 44 GW in Thousand Flowers. In Market Rules and Central Coordination, these surpluses last up to 400 hours per year, but in Thousand Flowers, surpluses occur for 2,973 hours per year, or 34% of the time.
The Market Rules pathway does not quite achieve an 80% reduction in CO2 emissions by 2050. Other mitigation measures may be necessary such as more hydrogen production for use in transport, and greater use of biomass energy. The other pathways are predicted to achieve an 80% reduction in CO2 emissions but may not quite achieve an 80% reduction in GHGs, including non-CO2 GHGs, without further measures. All three pathways result in an increase in the total amount of energy the UK must import in the coming decades, from about 300 TWh to 500 TWh or 1,000 TWh per year, with Market Rules again being the pathway with the greatest demand. The pathways also demonstrate the value if greater efforts at demand-side management can be achieved, for example through ‘smart appliances’ and peak-pricing helping to smooth the peaks in electricity consumption.