By Claire Simon
In his pioneering project ‘Charging the Earth’, David Nicholson-Cole of West Bridgford, Nottingham, shows how innovation and inventiveness in renewable technologies is possible at home.
Peveril Solar House has what David calls “the big three”: solar PV, a ground source heat pump, and a creation of his own, the solar ‘Sunbox’. The trio work together to simultaneously power and heat his house. But it is the last one, spawned from David’s own ideas and designs that gives the name ‘Charging the Earth’ to the project, and demonstrates the dedicated innovation that will underpin a 100% renewable future in the UK.
David’s passion for sustainable living stemmed from his work as a lecturer at the School of Architecture at Nottingham University. Working with like-minded individuals concerned about the anthropogenic impact on the climate, David knew he wanted to act on climate change and made the move to Good Energy in 2006. Not wishing to stop at buying renewable electricity, David decided to develop a house which generated and used its own clean, green energy to be “powered by sunshine, heated by sunshine”. The house has a ground source heat pump to provide heating and hot water, which was installed during its construction. Encountering problems with the normal horizontal installation of a heat pump due to the constraints of the plot, David opted for two deep drilled bore holes where the pipes which feed heat into the house plummet vertically into the ground: “Our storage boreholes go 48 metres below the house, reaching directly to about 8,000 tons of clay and rock”.
His next step in the development of a carbon neutral house was solar PV; the moment he heard that the government was introducing the Feed-in Tariff in April 2010 making solar PV a financially viable option, David didn’t waste any time in having a 4kWp solar array installed. Although costing £15,000, David says that thanks to the Feed-in Tariff he “can make most of the cost back very quickly”, estimating the time scale for payback at “eight and a half years”. He urges anyone thinking of a solar PV installation to act quickly, advising, “don’t let another summer go by and miss out on that harvest”. Since October 2009 the solar panels have generated over 3,000 kWh, and David hopes it will reach 3,300 kWh by October of this year.
In using the power of the sun to generate electricity and heat the house, David shows how harnessing locally available resources is viable. However, it is the visionary project, ‘Charging the Earth’, which demonstrates what is achievable with intelligence and commitment. The idea of the Sunbox came to David due to the performance problems associated with heat pumps over consecutive years: “Over successive years, a ground source heat pump tends to chill the ground permanently. After two years we looked for ways to prevent this chilling effect - hence the design and building of the Sunboxes for 'charging the earth'”. 
A concept designed entirely by himself with technical help from his colleagues, David describes them as, “miniature solariums, custom built solar panels injecting heat directly into the bore holes”. Acting like mini-conservatories on the South-facing wall of the house they essentially “recycle sunshine”, and although they “will not significantly raise the soil temperature, as there is just too much of it - the heat injection is equivalent to only 1 kW/hr”, the concept behind their development was in order to keep the ground around the heat pump at a warmer temperature even in the winter, cutting back electricity usage and making the heat pump more efficient over time. In fact the proposal for the Sunbox has been taken to Shanghai this summer to be presented to the global conference of Sustainable Energy Technologies. David sees his project as an example of the type of innovation needed for a renewable energy future: “In the electricity-only future, the heat pump will be the most energy efficient method of heating with electricity, so the research and development with Sunboxes could be significant for making future heat pump installations more practical.” With his dogged determination to craft a technology which uses the sun to increase the efficiency of other renewable technologies in his house, David is a natural ambassador for Good Energy’s homegrown movement, going the extra mile to make a difference.
To read Mr. Nicholson-Cole's blog click here.
