We're looking for total immersion in water's energy saving potential

The RE:NEW programme was launched in April 2009 to support the reduction of CO2 emissions from London’s homes and aid the fight against fuel poverty in the capital.

As part of this we’ve been working to find out the best way of further enhancing London’s energy efficiency through water efficiency, with the aim of rolling out free advice and measures across the capital, area-by-area.

Our technical trials saw 817 homes visited and around 600 tonnes CO2 being saved, and we have gone on to complete a larger demonstration project: a retrofit of energy and water efficiency measures in over 8,000 homes – over 15,000 basic water measures like tap aerators, aerated showerheads, shower timers and cistern displacement devices alone!

Measures are all well and good, I hear you say, but what’s the savings? Well since you ask, over 47 million litres water will be saved annually, which is enough to fill 19 Olympic pools. These water savings helped the programme achieve lifetime cost savings of a cool £3.735 million from energy and water bills.

We also learnt that per pound spent, water saving measures were some of the best carbon saving options for families.

So, onwards and upwards. But what else did we learn that can help us get the biggest carbon and money savings out of a scheme like this at best cost?

Well, firstly, looking beyond water alone, the whole-house approach offers more than just CO2 emission reductions, including water savings, advice and referrals to vital wider social support. It also helps avoid duplication of activity by enabling selection of wards that have not been or are not being targeted for energy efficiency improvements.

Door-to-door engagement got the best results in terms of numbers of home visits and bookings secured. The home visit approach also achieved high levels of satisfaction, and offered a good chance to talk through energy saving behaviour change to householders on a truly personal level.

However, evidence from the our evaluation reports suggests that this can be improved by continued promotion by project partners, particularly where a large-scale mail-out has been distributed, to ensure that residents are aware of the door-knocking activity.

Best value for money was achieved in the London boroughs of Lewisham, Southwark and Hillingdon where a bulk-buy approach to measures was in place, and by selecting the most cost-effective measures.

We also learnt that water companies were particularly enthusiastic supporters of all the private partners involved in RE:NEW, providing over £33,000 leverage for measures.

So what are we telling Government that can help make local and regional retrofit schemes like these work en-masse – something that will have to happen if we’re to hit our emissions targets?

Amongst other things, we think that smart-metering programmes should be integrated with future RE:NEW activity, but most of all, that water should not be left out when tackling our leaky housing stock. Energy and water efficiency in retrofit programmes should be forever entwined, as water efficiency measures are amongst the most cost-effective at reducing CO2 emissions and bills.

If the future’s going to be more sustainable it’ll be well worth immersing ourselves in water – not literally, of course!