HC 562 The effect on energy usage of extending BST

Memorandum submitted by Lighter Later (UKD 04)

The effects on energy usage of extending British Summer Time.

According to the latest peer-reviewed research, conducted by Dr. Elizabeth Garnsey et al. at the University of Cambridge, advancing the UK’s clocks by one hour in the colder months (from GMT to GMT+1) would lead to "energy [in this context meaning electricity] savings of at least 0.3% of daily demand in Great Britain". Garnsey predicts that a further saving would be made if the clocks were similarly advanced in the warmer months (from GMT+1 to GMT+2) though this prediction is impossible to model in the same way as the winter savings.

10:10’s Lighter Later campaign supports a three-year trial of SDST (GMT+1 in the colder months and GMT+2 in the warmer months) so that an empirical assessment of the benefits can be made.

The effect of extending British Summer Time on achieving UK renewables and emission reduction targets.

The paper described above suggests that a conservative estimate of the associated reduction in greenhouse gas (GHG) emissions would be "approximately equivalent to 450,000 tonnes of CO2" for the winter shift alone. This reflects the fact that in addition to reducing demand for energy, the change could reduce the average carbon intensity of electricity by reducing peak demand.

The clock change could impact on renewables targets in two ways. First, reducing demand necessarily makes it easier to hit a percent-based supply target for renewables.

A second possible impact would be to make domestic solar power more financially attractive. The Energy Saving Trust states that "with more sun light in the afternoon and evening (as would happen with DST throughout winter), households with solar photovoltaic systems could benefit from having more electricity from their panels available to them at times when they are more likely to require it." If this turns out to be true, then the structure of the feed-in tariffs would mean higher rewards for solar-panel owners further incentivising uptake.

The effect of extending British Summer Time on the wider climate change narrative.

In the popular imagination, climate policies are often associated with austerity and frugality. These negative frames hinder action and lead, in our opinion, to lower levels of support for climate change mitigation.

10:10 aims to challenge this perception, not only by showing what’s possible in the short term, but also by promoting a positive, inspiring vision for how much better a low carbon society could be. This positive narrative helps to unlock public support for wider green initiatives.

It was in this spirit that 10:10 launched the Lighter Later campaign in March 2010. Changing the clocks to align daylight with waking hours is a policy which, for minimal cost, reduces emissions whilst promising a wide range of co-benefits – from tackling obesity to creating jobs in the tourism sector. In other words it’s a concrete demonstration that cutting carbon and improving people’s lives go hand in hand.

This approach has been vindicated by the extensive positive coverage Lighter Later has received from organisations as diverse as Mumsnet, the RAC and the Sun. It is our belief that success with Lighter Later will open the door to a range of new policies from warmer homes to better power generation.

October 2010