Pumps:up the volume
February 1st 2008 Isoenergy boss, Justin Broadbent is betting his business on heat pumps because,he says, no other 'renewable' currently delivers any viable payback. Brendan Coyne reports
According to Broadbent, whose company Isoenergy specialises in specifying, installing and commissioning ecologically sustainable and cost justifiable heating and energy systems, the 'green lobby' has a problem with heat pumps because they are perceived as energy users.
Heat pumps do consume power, but a well installed unit puts out five times as much as it uses, and Broadbent says within 10 years the coefficient of performance (COP) could be 20:1 and certainly 10:1.
The company has installed numerous systems in commercial premises, including open loop systems which suck water out of the ground/river/sea, extract the heat from it and return the water to its source; and closed loop systems, using pipes buried a metre underground to extract heat (around 10-12°C) from the earth.These can be enhanced by using propane.
Because the system has 10°C coming out of the ground into the heat exchanger, and on the other side of the heat exchanger propane,which boils at -20°C, the resulting gas can be compressed (which makes it hot), passed through another heat exchanger and used to heat underfloor systems or radiators.Using propane in an extended heat pump (running plastic sheathed copper pipe outdoors) creates a direct transfer – the most efficient method, according to Broadbent, and common in France.
But in the UK it's the rarest, driving just 5% of heat pumps.
The fourth way is using an air-to-water heat pump.Given that average midwinter temperatures in the South of England are some 6- 7°C, Broadbent says air-to-water is just as efficient as ground source for the average domestic property – because even with well spread pipes, the ground will be cooler if the heat is constantly taken out of any given area.
Payback from heat pumps is between 7-15 years. But Broadbent says that within 10 years, if oil and gas prices continue rising at current rates, the payback could be as little as three years.He says cheap fuel is hampering uptake in the UK,whereas they are far more prevalent in Scandinavia,where oil is taxed highly whether for heating or motoring."In Sweden oil is 92p per litre regardless...The only thing holding heat pumps back in the UK is that we have cheap fuel.Why would you install one if it takes 15 years to get the money back?" But lengthy payback periods haven't stopped firms installing PV cells and wind turbines, so why should it affect heat pumps? Being technologically agnostic in terms of fulfilling clients demands, Broadbent is nonetheless withering in his assessment of other renewables.
"Solar PV is only ever done in this country to make a political statement. I have never worked on a site that I've considered will have a payback of less than 60 years,"he says."I would love it if PV was the answer to every maidens'prayer but in reality it's a joke." However, Broadbent believes that in 20 years time, PV could become the solution. He cites technological developments, such as solar technology that works on plant photosynthesis principles recently patented by a university in South Africa – that only costs a 10th of traditional silicon methods to grow and manufacture – as a potential answer."I can see that in 20 years time we'll be using PV cells as roof tiles" says Broadbent."But right now I don't think PV is a good idea. In fact it should be illegal." Broadbent believes smallscale wind turbines are equally unfeasible citing that, if a 2kW roof mounted turbine will produce around 300W on average, at 6p per kilowatt hour the payback will be 30 years on a £5k turbine installation cost."And the life expectancy of the system is only 20 years, so you've lost money."
While commercial windfarms are more efficient and generate payback, Broadbent believes "somebody"will do the maths and work out they aren't a viable solution to renewable generation."The problem is,what happens when the wind stops? Do we say,'sorry Newcastle,you can't have any power today'?".Whereas Denmark, which produces 20-30% of its electricity from wind can get around windless periods by using France and Germany as batteries,the UK cannot.
Because 60m in population is very different to Denmark's 4 million."We can't exactly turn around to France and Germany and say 'can we have some electricity please?' Broadbent says if the government invested the £billions it intends to pour into Danish wind turbines into R&D to harness tidal energy the UK would have an endless power supply: "You can't stop the tide coming in," he says."Canute proved that." In the meantime,Broadbent says he is betting his business on heat pumps.
But,at risk of scuppering future contracts, says businesses should concentrate on the basics before looking to mechanical solutions."The truth is to sort out your installation.
Designing and building properly in the first place is something we remain a long way off in this country." | 
