The group’s research is looking at existing housing developments from the 1970s, 1980s, 1990s and 2000s to determine the scope and potential impact of microgeneration technologies and energy efficiency measures on the residential scale.
Microgeneration options assessed include:
- Photovoltaics
- Micro wind power
- Solar thermal systems for domestic hot water
- CHP (combined heat and power) at the individual house and small community scale (cluster of houses)
- Ground source heat pumps
- Insulation and boiler upgrades
Principle of a housing cluster CHP system to provide better thermal load matching. Excess electricity is exported to the local network beyond the cluster.
Detailed dynamic simulation models of various housing types and occupancy / usage profiles have been developed using TRNSYS thermal simulation software. These models predict the heating and electrical demand of houses on an hourly basis and the matching that various microgeneration technologies are likely to achieve (avoided export, heating from CHP). The analysis assesses the CO2 reductions that can be achieved with various take-up scenarios. Furthermore, the energy, carbon as well as the financial payback times are being assessed. CHP is a highly promising technology to deliver significant CO2 reductions but is far more complex to predict in terms of operation profile than other microgeneration technologies. Therefore, both single user (micro-CHP) and housing cluster applications as shown in the top figure are being assessed.
Thermography image showing an open window acting as a major heat loss pathway.
Thermography image showing that a poor level of insulation creates a thermal bridge for the heating system pipework.
The following research approach in four steps was taken:
- Questionnaire survey of residents of a typical housing development to determine occupancy, key housing details and energy demands.
- Aerial photo analysis of the same building stock to quantify the potential solar resource available to typical housing (orientation, level of shading).
- TRNSYS modelling of different microgen technologies with different housing stock and user profiles (retired people, professional working couple etc).
- Assessment of thermal performance of the surveyed building stock in relation to TRNSYS predictions through external infrared thermography surveys. Estimation of building quality and potential impact of user behaviour on thermal demands (opening of windows, very high temperature set-points of heating systems etc.).
Aspects of this work have been published in:
Papafragkou A., Bahaj A.S., James P.A.B. and Jentsch M.F. (2006) Energy flows in domestic buildings: residential combined heat and power (CHP) microgrids. Proceedings World Renewable Energy Congress (WREC-IX), Florence, 19-25 August 2006.
Papafragkou, A., James P.A.B., Jentsch M.F. and Bahaj A.S. (2008). Street level microgrid concepts for Southampton, UK: Estimating climate change impact on energy flows and emission, Proceedings World Renewable Energy Congress (WREC X), Glasgow, UK, 19-25 July 2008, pp 711-717.
Papafragkou A., James P.A.B., Jentsch M.F. and Bahaj A.S. (2009) Combined heat and power: street-level domestic microgrids, Proceedings of ICE, Energy, Volume 162, Issue 3, August 2009, pp 131-141.
Papafragkou A., James P.A.B., Bahaj A.S. (2011). The impact of the GB Feed-in Tariffs and Renewable Heat Incentive to the economics of various microgeneration technologies at the street level, Proceedings World Renewable Energy Congress 2011, Sweden, Linköping, Sweden, 8-13 May 2011.