Heat pumps.

No you wouldn't because you're not allowed to plant anything over the pipes but grass (and chickens ). Best solution in UK would be a deep-bore, vertical, true geothermal system. We had one memorable winter with 10 days of sub-zero temps and a metre of snow. The temperature in the house dropped slowly from 21C to 16C. Bearable but not fun with an immobile elderly lady in the house

 

I do a bit with heat pumps. They work the same as a fridge (vapour compression refrigeration cycle) For a fridge you want to keep the inside cool so the heat removed from the cool part plus the energy input from the mains gets rejected out the back of it at the condenser. In a heat pump the cold bit goes outside and you extract heat from the environment, add the electrical energy to run the compressor and reject the heat and electrical energy into the building.

Up till recently its been a hard one to justify against natural gas as most people want to save money not the planet so the cost of gas to electricity is important. The efficiency of a heat pump or refrigeration cycle is called its coefficient of performance. For air source it might be about 3 to 3.5 so for every kw electrical energy you get 2 or 2.5kw from the environment and reject 3 to 3.5kw into the building.

The newer air source ones are running on refrigerant R290 (propane) which thermodynamically seems to be a fairly good refrigerant and the COP's are better.

Main thing that governs how efficient its going to be is external ambient temps and flow temps to the building as these govern the pressure difference that the compressor has to operate over. The higher the pressure the more electrical energy is needed and the lower the COP generally for a given refrigerant.

I'm working my way through our house insulating it and installing underfloor heating as will eventually have to get rid of oil boiler I recon. If I can get hold of one I will install a ground source one myself.

 

Boreholes are prohibitively expensive for most people in UK. Going to a project tomorrow to look to install 7 (from memory) Will be about 65K for the boreholes alone.

 

Boreholes are the best though. 2nd best is probably a lake/ river followed by horizontal ground loops then air source. Boreholes being true geothermal don't vary in temp with the seasons or at least its negligible. Lakes or horizontal loops are really large solar absorbers but a metre or so down the soil temp varies less than the surface layers so in winter when you need heat you are still drawing it from somewhere that's reasonably warm, providing collector sized ok. Main issue with air source is that its at its least efficient when you need the most heat - ie trying to get heat out of air that may be at -1 deg C for example.

 

Nuclear power - zero emissions - everyone uses electrical heaters - that seems logical/sensible to me. But then, what do I know

 

You do get the problem of radioactive waste.

 

So you couldn't turn it up then?
This is where you are going to start using extra heating along side the pump then.
Which kind of defeats the object, doesn't it.

 

How about reusable rockets (Blue Origin) to shoot the waste into the Sun - set it on course from orbit and inertia will take it to the Sun. A rocket exhaust consists of water vapour apparently.

The solution is simple - but then I'm no rocket scientist..

 

Me and my dad have scratched our heads for years about trying to tap in to the heat source from the organic mulch we stock. At the moment I have approximately 15000 cubic metres of loose mulch in a polytunnel, this is a mixture of composted bark, spent mushroom compost and horse manure. The heap actually touched the top of hoops but has already shrunk due to compression and decomposing.

The heat it generates would go along way in cutting down on our heating bills, not just for our homes but also the glasshouses. The trouble is, how do we put pipes through the mix that still allows us to fill and empty the tunnel without damaging the pipes with the loading shovel. The pipes would have to be off the ground as the moisture tends to be at the bottom of the heap, which tends to be cool, so wouldn't really heat the water at all.

 

The big problem with heat pumps and efficiency is the pressures that they have to work between. The evaporator or cold bit needs to run a few degrees under the temperature of the source of heat - so it can pull heat out and it needs to reject heat at a temperature that suits the heating system. Most people have radiators which are normally designed to work with a flow temp of about 80 deg c. Often oversized but when you try to run a radiator circuit at say 55 deg C flow (which is as high as you really want to with a heat pump - ideally much lower) the output from the radiators drops like a stone, roughly 50% reduction, which is why underfloor heating is the preferred heating system but even that can be tricky to get to work, especially in older properties.

The other issue is if every one tries to install a heat pump the electricity network will not be able to cope. I have been getting a 3 phase supply in here and was speaking to Scottish Power Energy Networks. Its a real concern for them as there is really no spare capacity in the network to accommodate electric cars and heat pumps on the scale that's being banded about - especially in city centres etc. I think the gas boilers will go onto a gas hydrogen blend before long. I'm not sure we will be able to be on heating oil much longer though so starting to make the transition as I renovate.

 

Not if they get Fission to work properly. They seem to be making progress but it will be a while yet before all the issues are ironed out with that option I would think.

There is talk of a pilot fission reactor in the UK.

 

I am just up the road from Sellafield, it is one of the sites short listed for fission reactors.

 

Well, we could have done but it would have been running purely on the mains. If we were starting again from scratch, I'd have a wood-burner as back-up, preferably with a strapping young Frenchie to fell, cut, chop and carry the logs

 

Nuclear fission, that rings a bell from way back when, basically when Britain led the world in nuclear energy and the government pulled the rug from under it.