The Davey Heat Pump
March 23, 2014
By Paul Homewood
The Energy Secretary, Ed Davey, has described the development as "game changing" in relation to Britain’s need for renewable energy.
I am sure we would all welcome an abundant supply of cheap, reliable energy.
So, perhaps, Mr Davey might like to consider an immediate moratorium on further development of expensive, unreliable wind power, while this new technology is investigated?
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NOT A LOT OF PEOPLE KNOW THAT 
I will wait and see how this one pans out, but heat pumps are not always that efficient. It is true that a heat pump from a water source is probably the best since the temperature of the “source” will be more stable. in terms of rising efficiency you have air, ground, water sourced heat pumps. The costs also rise appropriately.
The domestic heat pumps use electricity although Coefficients of Performance (COP) from 3.5 to 5 are often stated (in other words 1 unit of electricity in produces 3.5 to 5 units of heat out) – but these usually turn out to be a bit like mpg figures for cars. The higher the output water temperature of the pump (as is being suggested in the article) the lower the COP – you don’t get ‘owt for nowt’. I seem to remember reading that efficiency falls 5% for every extra degree C you warm the water.
On small scale heat pumps you currently get a handout of taxpayers’ money to encourage take up – now this is because they are viewed as “renewable”. Of course it all depends on what is used to generate the electricity. If that is in truth mostly gas/coal then the whole thing is a charade. Frequently COP falls to 2.5 to 3.5 and it is worth remembering that electricity is on average three times the price of gas. It is just that the numpties running DECC are trying to stop you using gas and force you to use the “renewable” electricity – you couldn’t make it up, but they did. That is why they are desperately burning trees to save CO2 – you couldn’t make that up either, but again they did.
Ironically heat pumps work best in a highly insulated air-tight property (and these new ones built in the test properties will be I assume), but if you have such a property you don’t need much heating at all anyway. a big sledge-hammer to crack a small nut.
Don’t get me wrong heat pumps have their place especially if gas is not available to you and work well if designed properly for underfloor heating in well insulated house. Creating loads of hot water for your bath or shower is more problematical, and expensive disasters have been produced, since usually an immersion heater is used to “top up” the temperature.
Also it doesn’t take much thought to see that if we went down this route in a big way, you would move a load of people from using gas to using electricity – OK we save on gas and two fingers to Russia, but where we generate the extra electricity from is another matter.
In the United States we have a large installed base of air-to-air heat pumps. We do a lot of summer air conditioning and without much additional expense you can also use an air conditioning unit in the winter as a heat pump. They incrementally reduce heating costs because they are efficient, but they are not efficient or even effective below a certain temperature. Outside air temps at -10C and you are getting next to nothing.
I have a groundwater heat pump at my home and it has a broader operating range but is dogged with the same declining efficiencies. Over the course of the heating season the ground water drops a little in temperature and it has a big effect on the net heat extracted from the heat source. By February or March I get only a fraction of the heat compared to October, November. Supplemental heating source is a necessity.
I’ve run ground water heat pumps for twenty years now. And I keep costs and numbers pretty straight in my head. I can tell you I haven’t saved much money, (maybe nothing) over heating with propane (natural gas isn’t available in my rural setting). With natural gas now costing us about $5 a therm retail – it wouldn’t even be close.
It’s a way, way, way better deal than windmills which are variable, intermittent, undependable and unscheduled)
So, if gas is cheap enough – don’t even think about it. Heat pumps are a big multiplier in complexity and capital expense.
Phrasing (all false) indicating that the hoax is still upon us:
“. . . carbon-free technology . . .”
“. . . 500 tons of carbon emissions . . .”
“. . . in a revolutionary system . . .”
We have an air-heat-sourced home AC/Heat system powered by electricity produced by generators in a dam on the Columbia River 30 miles away. I suppose that is “technically zero carbon” but I think someone with a sharp pencil can prove otherwise. Anyway, I don’t find the UK scheme compelling and do not believe it will be “game changing.”
Think of the many thousands of pipes (digging ditches, tearing up streets and neighborhoods). Are the pipes to be carbon based, steel, concrete, or what? Will they ever leak, and when one does, what will be the consequences? What will the green-lobby think of harvesting the heat from a lake or river (or the reverse in Summer) and returning cooler water to a different spot?
Note, I understand how this process works. “Game changing” it is not. It is just one of numerous solutions to a non-problem. Energy Secretary, Ed Davey needs to get a grip on reality.
The heat pump I dealt with was fine as long as the temperature stayed above 5C. Once it went below 5C it became less and less capable of heating the house I lived in.
The article states:-
“A small amount of electricity is used to power the system, but this is supplied by Ecotricity, which makes it technically zero carbon.” [My bold]
The real-world Coefficient of Performance of the heat pump will be of the order of 3.5. [i.e. 1 kWh (power) consumed would provide 3.5 kWh of output heat, so 28% of electricity is used solely to power the system. And that’s simply the heat exchange ratio. Because the heat medium is water (rather than air), and it’s sourced from the river, there will be fairly hefty pumps (electrically driven, of course), required to circulate the water from source to system.
What happens when the guy upstream pinches all your heat? Also who gets sued when there is an outbreak of legionella from all this lukewarm water sloshing about? What could possibly go wrong?
Not to mention all the dead fish!!
What an amazing phenomenon Climate Change must be.
When it was Global Warming we had regular scare stories about how aquatic life may be susceptible to 1/10th degreeC change.
“Climate change and fish:- Our oceans and fish stocks may be under threat from changing water temperatures. Fisheries and communities around the world could be affected.
If our climate changes, the temperature of oceans, seas and lakes will change too. We don’t yet know the full impact on fishing and marine ecosystems, but it seems likely that vulnerable marine species will be under more pressure.
Many fisheries will be seriously affected as the ecosystems that underpin them face new and uncertain challenges.
How will climate change affect fish and fisheries?
The Intergovernmental Panel on Climate Change predicts that:
as sea temperatures change, fish numbers will change and fish will move to different areas
some species will go extinct in particular areas
predators and prey will move to different areas, disrupting food chains
wetlands and other low lying habitats where fish reproduce will be covered by rising sea levels
water in lakes will get warmer”
Now, Davey the Dunce, wants DECC to consider national use of a technology that’d change river and lake temperatures by up to 10x the amount the IPCC considers potentially risky!
What about this http://www.vortexhydroenergy.com/ since we are looking at rivers etc.
I wrote to my local [ SNP Mp ] about this about a year ago. Usual politely dismissive response despite the vast resource of river and loch currents up here….not to mention the rest of the UK
Looks like a load of PR men who can’t do simple arithmetic dreamed this up, how many such units can be installed in – say – the Thames before the temperature is reduced sufficiently to screw up the river’s ecology?
With this kind of technically naïve minister, his fellows at Government shall have laughed a lot….
Herve