1 CRed Carbon Reduction N.K. Tovey ( ) M.A, PhD, CEng, MICE, CEnv Н.К.Тови М.А., д-р технических наук Energy Science Director CRed Project Recipient of James Watt Gold Medal for Energy Implementing New Technologies for an Energy Efficient Home 1 Overview of advances within the sustainable built environment for domestic buildings 20 th May 2009

2 Advances within the sustainable built environment for domestic buildings Barriers and drivers to implement novel new technologies in domestic buildings. Domestic renewable energy technologies – Solar thermal Solar PV Combined heat and power (CHP) The challenges of integrating renewable energy sources into domestic buildings

3 A Partnership between – Broadland District Council – University of East Anglia Launched by publicity with an open meeting attended by ~120 Aims –To promote Solar Water Heating by a community to enable bulk discounts Required a minimum of 50 participans to sign up within 3 weeks Over subscribed in 22 minutes! Subsequently 9 properties not found to be suitable –To develop skills for installing Solar Hot Water Heaters in the region Technical Opportunities: Solar Thermal: The Broadsol Project

4 Solar Collectors installed 27th January 2004 Annual solar collection kWh/annum The Broadsol Project

5 5 Mean Monthly Solar gain for 11 systems 3 panel systems The Broadsol Project Three panel systems captured only 13% more energy compared to two panel systems Effective use is not being made of surplus in summer Some 2 panel systems captured twice the energy in summer months.

6 Technical Solutions: Solar Thermal Energy

7 Measured System Efficiencies System Efficiency of 2 panel systems is higher than 3 panel systems 2 panel 3 panel

8 8 Tilt Angle variations are not significant in region 0 – 45 o Optimum orientation in East Anglia is SSW South West is as good as South

9 The more Hot Water is used the more Solar Energy is Collected Sky became hazy at ~ 11:00 Substantial hot water demand at 13:30 Normal heat loss from tank shown in black kWh extra heat collected. Note: small gain at 18:30. - even more would have been possible had collector been orientated SW rather than S BS27: 15/05/ kWh 0.911kWh 1.157kWh0.083kWh

10 Technical Issues requiring awareness raising: Solar Thermal Energy 10 Tank with small residual hot water at top of tank If CH boiler heats up water – less opportunity for solar heating. If boiler is not on – more solar energy can be gained. Boiler ON/OFF times should be adjusted between summer and winter for optimum performance

11 Technical Issues requiring awareness raising: Solar Thermal Energy 11 Tank with small residual hot water at top of tank In this case no boiler hot water heating is used. Gain from solar energy is much higher

12 Store Temperature Variations The Broadsol Project Education of how to get best out of solar HW systems is needed.. Need to adjust timing of central heating boiler over late Spring, Summer and early autumn. On day one, if boiler supplied hot water as per normal top of tank would be heated to 55 o C and reduce the solar gain by 21%. On day 2, the loss would be negligible, but if the store temperature was as low as 20 o C the loss in solar energy can approach 40%. Day 1 Day 2

13 Technical Solutions: Solar PhotoVoltaic 13 Zuckermann Institute for Connective Environmental Research. (ZICER) Low Energy Building of the Year Has heat demand ~ 20% of building of its size: 34 kW of Solar Photovoltaic on roof and facade

14 Arrangement of Cells on Facade Individual cells are connected horizontally As shadow covers one column all cells are inactive If individual cells are connected vertically, only those cells actually in shadow are affected. Cells active Cells inactive even though not covered by shadow

15 Technical Solutions: Integrated use of PV generated energy Inverters are only 91% efficient Computers and other entertainment use DC. Power packs are inefficient LED lighting can use DC Need an integrated approach – houses with both AC and DC with heat recovery from central inverter/rectifier?

16 Technical Solutions: The Heat Pump Works best with underfloor heating The potential for significant CO 2 savings

17 Preliminary data from installations in Norfolk. Objective data on comparisons between different strategies is needed. Identical houses with different low carbon strategies. Significant variation in electricity consumption. Surprisingly, overall emissions from houses with Ground Source Heat Pumps were inferior. But variation in appliance use between one house and another was large. Is this masking saving? Or was the collector loop correctly sized?

18 Micro CHP Technical Solutions: CHP Micro CHP plant for homes are being trialled. Replace the normal boiler A problem in summer as there is limited demand for heat – electrical generation will be limited. - Peak electrical import can occur at time of minimum demand. Backup generation is still needed unless integrated with solar photovoltaic? In community schemes explore opportunity for multiple unit provision of hot water in summer, but only single unit in winter.

19 The Behavioural Dimension 19 Social Attitudes towards energy consumption have a profound effect on actual consumption. Data collected from 114 houses in Norwich between mid November 2006 and mid March 2007 For a given size of household electricity consumption for appliances [NOT HEATING or HOT WATER] can vary by as much as 9 times. When income levels are accounted for, variation is still 6 times

20 There are many opportunities of low carbon buildings. Creative integrated solutions are needed. Need to address the issue of the behavioral dimension towards energy use. Opportunities for community collective action – for cost effective solutions should be explored. Opportunities for more effective use of solar hot water/CHP schemes warrant attention – Housing Associations? Conclusions Lao Tzu ( BC) Chinese Artist and Taoist philosopher If you do not change direction, you may end up where you are heading.