1. FORREST UK Author Session 4 – Block 4 – Question 8 Barcelona 12-15 May 2003 1 Accommodating High Levels of Domestic Generation Simon Forrest Dr Robin Wallace University of Edinburgh, UK

2. FORREST UK Author Session 4 – Block 4 – Question 8 Barcelona 12-15 May 2003 2 Initial Studies Review of domestic generation inc. DCHP Modelling of an urban distribution network Preliminary simulations indicated –No voltage violations –Reverse power flows up to/including nearby substations –Transformers at nominal 11kV:400V

3. FORREST UK Author Session 4 – Block 4 – Question 8 Barcelona 12-15 May 2003 3 Update - I Transformer design setting 11kV:433V –to compensate for high load voltage drop Voltage rise resulting from high DCHP penetrations causes violations at 400V –Manual adjustment of tap setting at local and, if necessary, nearby transformers –Retro-fit auto-tap changers?

4. FORREST UK Author Session 4 – Block 4 – Question 8 Barcelona 12-15 May 2003 4 Update - II Ultimately, tap adjustment will depend on profiles of large numbers of DCHP –UK Electricity Association study

5. FORREST UK Author Session 4 – Block 4 – Question 8 Barcelona 12-15 May 2003 5 Future of DCHP Need EU-wide perspective for critical mass UK OFGEM target of 1-3 million by 2010 –1 million possible, 3 adventurous! Some key barriers –Upfront capital costs –Consumer confidence –Confidence and backing of tradesmen Could be alleviated by ESCo provision

6. FORREST UK Author Session 4 – Block 4 – Question 8 Barcelona 12-15 May 2003 6 CIRED 2003 This work is part of a larger ongoing programme at the University of Edinburgh Papers presented at CIRED –4.44 - Intelligent generator control –4.62 - Domestic CHP –4.63 - Optimal accommodation of DG