At the start of the new millennium more people were dying in the winter from the cold weather in Britain than in any other European country, including Siberia, where temperatures regularly drop as low as -40C.
The actual UK death toll might be even higher than official figures suggest as very few death certificates give the cold as the cause of death. Research by Professor William Keatinge, of London's Queen Mary and Westfield College, found more deaths in people over 55 years of age caused by the cold are attributed to strokes and coronary thrombosis rather than flu. According to Professor Keatinge; "Many people here simply do not take the cold seriously and appreciate the danger it poses.”
The situation is unlikely to improve in the future. The UK’s reliance on imported gas is projected to rise from around 25% in 2008 to over 60% by 2020. Couple this with ever rising global fuel prices and this is leading to more and more UK households spending an increasing proportion of their income just to keep warm.
Official statistics identify households as being in fuel poverty when the ratio of fuel costs (usage x price) to household income rises above 0.1. The cost of energy is unlikely to fall in the long term and household incomes are static or falling in the current recession. The only element of the calculation that can be easily changed is the level of usage of energy.
When households reduce usage too far then people start to die. The warmth of the home still needs to be maintained while usage is reduced. Fitting double glazing and programs to improve wall and roof insulation have been running for several years but what is needed now is a more radical re-think of how the UK keeps warm in winter and technologies such as ground source heating may provide some of the answers.
A ground source heat pump uses the same principle as a domestic refrigerator. A fridge uses a closed loop system to pull heat out of the inside of the fridge and radiate it into the atmosphere from fins on the back. Anyone who has ever put their hand behind a fridge can tell you that these fins can get very hot. A ground source heat pump uses buried pipes filled with a water/antifreeze mix to pull heat from the earth and then to warm a building through radiators or under floor heating.
Theoretically there is no limit to the amount of heat that can be extracted from the ground, the longer and deeper the underground pipes the more heat that will be pumped. Unfortunately scaling up too far reduces the coefficiency of performance (CoP) of the system. This is a measure of the amount of heat produced compared to the amount of energy needed to drive the circulating pumps that push the water/antifreeze mix round the pipes. The best systems will deliver a CoP of around 3.2 but it does mean the homes being heated need to be fairly close to the ground source pipes
Many of Britain’s European Neighbors are well ahead of the UK in adopting this type of technology. The Dutch city of Heerlen uses a heat pump from abandoned coal mines going down to 800 meters below the city to run the radiators of hundreds of homes, shops and offices. According to Riet de Wit, a City Councillor in Heerlen. “We have proven that a local initiative can provide a local solution for sustainable energy. Moreover, our concept can be adapted by former mining regions all over the world.”
The Dutch system was developed by Karl-Heinz Wolf, Professor of Coal and Geothermal Energy at the Technical University of Delft. “You have it all year round and if you don’t need it, you close the tap until you need it again.” The system can even work in reverse during the summer. In the hot months the water can be taken from near the top of the shaft where it is cold enough to cool the city’s buildings. Professor Wolf is now working on a project to extract heat from a depth of 2.5km where the temperature of the water is 80-85C. “It is not difficult to do” according to the Professor, “the only thing you need is a mine which is in the vicinity of the industry or houses you want to heat.”
Unfortunately while these systems may be cheaper to operate and offer an effective, sustainable long term solution, they also cost much more to install than conventional gas or electricity powered systems. This makes them attractive to households that can afford to invest for the longer term but these are households that are very unlikely to currently be experiencing fuel poverty.
This problem was acknowledged by the government in February 2010. During a visit to a low income homes project in Dagenham the Energy and Climate Change Secretary Ed Miliband announced that; “We are launching a scheme, the Renewable Heat Incentive, to encourage renewable heat generation at all scales.”
Joan Ruddock, a Minister in the same department, told the Ecobuild Conference at Earls Court in March 2010 that; “The Renewable Heat Incentive will deliver a step change in the way that the country generates its heat for heating hot water and our homes”
Any house or building which currently uses fuels such as gas, heating oil or coal, will be eligible to claim the RHI if they switch to a renewable technology. The RHI will be available to householders, local authorities and social landlords as well as the public, industrial and commercial sectors.
Fuel poverty is only one issue that can be addressed by ground source heat. Currently 60% of average total domestic energy bills are consumed by heating costs but domestic heating also accounts for 47% of the UK’s carbon dioxide emissions. In order for the UK to meet its carbon reduction obligations 12% of UK heat is required to come from renewable sources. The RHI could save up to 60 million tonnes of carbon dioxide by 2020.
In addition to the environmental damage done by Carbon Dioxide production there is also the risk to heath posed by Carbon Monoxide which is produced by incomplete combustion in gas heating systems. On average over 30 people annually die from Carbon Monoxide poisoning. Heat pumps not only completely remove this risk as they produce no carbon monoxide but also remove a significant legal liability for safety from the housing provider and of course tenants are spared the possible fatal consequences of poisoning or even a gas explosion from incorrectly maintained systems.
Ground Source Heat pumps are also very suitable when water temperature safety is a concern. Typically Ground Source heat pumps produce water at around 60°C, considerably lower than the 90°C output by gas or electric heating systems. These temperatures are more than adequate for water for baths or showers but make it impossible for children or vulnerable adults to inadvertently scald themselves.
Details of the Renewable Heating Incentive can be obtained from the Department of Energy and Climate change (decc) Website. Details of Installers of Ground Source Heat pumps can be obtained from the Heat Pump Association, Waltham Court, Hare Hatch, Berks RG10 9YH or from their website, http://www.heatpumps.org.uk