I am looking at ways to make my barn conversion enegry efficient. I am allready adding more insulation then specifed, but want to go further. The site is unsuitable for solar power, as the roof is in shade too much of the day (large oak trees) However I have been looking at windmills and ground heat pumps, I have plenty of ground or even a river for the heat pump, given that there is now planning approval for a HUGE windmill just up the road for me, there must be plenty of wind.
Does anyone have any ideas how you could use the windmill to pump the heat out the ground and store it in a heat store ? Has anybody done this ? We have HUGE ammounts of wood, so will supplment the system with real fires.
Depends on the time you can run them flat out. But agree, alternative energy isn't exactly always cost effective - unless you haven't got an electricity supply in the first place. Then it looks most attractive.
The payback period is reduced for me, I have only 60A of electric, and when I put the shower on, the lady up the valley looses her TV picture. We are 1/2 a mile from the road, and can't get a gas or oil tanker down the track ......... This is not too bad for the current 2 bedroom weekend retreat, where a wood fire is fun, but once the extra
3 beds, 2nd bathroom, 3 sitting room is added 60A is not enough power in the winter.
The river can not get ehough head for a turbine.
Prices are MUCH cheeper if you source from outside the UK, for example wind turbines in the US are about 1/3 of the cost ......
Anyways the question remains, have you actually installed one of these things ? How do you link the various system together to overcome the limitations of each. For example when there is no sun, there is almost certanly wind and rain ........
I am worried, I did under floor when before it got big, and I paid top prices compared to today. I think I am about 10 years too early for the prices to be right on this technology .........
CAT appear to use their stuff to make electric, I want to make heat. The heat pump basicly sucks heat out of the ground, at an ideal temperature to run underfloor heating. However you can over cool the ground, and it stops working. You can't (easilly) overcool a river, so if I can suck the heat out of the river with free wind driven electric, and store the heat till needed, I have free heating, To me this theory sounds great, but there are a number of issues, which I have no idea how to answer (heat stores run hot, but ground heat is wharm not hot). In summer you don't need much heat, but in winter when wind and river are plentifull you do. To simple old me, who/whatever disigned the world designed it for this application, but us humans appear to have not quite got there yet.
Of course if nobody has done this, then I see a business oppertunity, if I can find a bright person who can make it work ....
That should not happen. How far up the valley is this lady? Do you share the same transformer? Thought about contacting the electricity supplier about getting a bigger transformer? This isn't going to be anything like as expensive as getting a feed run in. Indeed they may come out, inspect, and simply change your meter and cutout to bigger ones. Our cutout is 100A, the one on the pole 200A...
Not even one of the mini ones? Most oil suplliers in rural areas have small tankers for getting to difficult places.
You have a massive, normally lead acid but wet NiCDs can be used as well, battery bank or you use the grid as a "battery". That is you install a turbine that more than meets your normal demand and you sell the excess to the grid. When the wind drops or your demand exceeds the capacity of the turbine you take power from the grid. You get paid for the power you feed to the grid and pay for the power you use from it, get the sums and turbine size right you generate more than you use...
To be honest if you talking loads of 10kW I don't think a local battery bank is suitable but the "battery" grid is. It also means that you don't have to install a turbine to cope with the peaks, just your base load plus a surplus. A 10kW wind turbine is quite large (from the galeforce site 10kW has rotor dia of 7m (23')), a 3 or 4 kW one is big but not quite as bad.
Except the river is likely to be close to surface temperature, a heat exchanger in a deep hole looks at a constant 10C, so there is less temperature difference to make up, and the coefficient of performance varies with delta T.
Why convert it to electricity, just run the compressor when the wind blows. I advertised an unused compressor from a military air conditioning unit free to collector, here some years back, no takers but it ended up in an old water mill in the west country IIRC running as a heat pump.
Well you have heating free of fuel cost, other costs must be considered.
Ah right ignore the latter half of my other post wibbling about 10kW
7M wind turbines etc...
Erm why do you need to store the heat? If comes out of the ground at the right level for the heating system, when you want heating you just turn on the pump like you would turn on a boiler. The pump isn't going to take a vast amount of power so why bother with the expense of an unreliable (mechanically and wind) turbine?
But you are pumping the heat not just letting the heat move on it's own accord. True it's low grade out of the ground (river) but I think the pump will push it up quite away.
Vallies with lots of distance and very few people are not economic for the lecie people to upgrade. The lady up the valley is a bit of an old bat, so almost certanly gets the "silly old bat" responce when she phones to complain.
The biggest thing to come along the track is a 4x4 car, else you can't turn, unless its a dry day and you have a 4wd tractor ..
Lovley location, not exactly pratical ..... :-)
I was working on a a 10kW turbine, I guess my way forward is to talk to the lecie board and see what "grid connaect" will cost me, so I can sell back.
I wouldn't say so. The capital cost of the heat pump minus the capital cost of an oil boiler is the end cost. The cost of any heating system should not be taken in to account as you need that with any heat source.
Superinsulation and thermals bridge reduction/elimination is essential where you are. Can you have a solar panel array on a frame separate from the main house? If so, go for this. Superinsulate and have "very" low temp UFH heating in the house run from the thermal store. This is by far a more cost effective approach than wind or heat pumps. 60 amps is fine if electricity is minimised and very low energy appliances are used when you need them. My recent post on this is pasted below.
The Building Structure:
- A light framed superinsulated structure (Minimum of 400mm of Warmcell in the roof, 250-300mm in the walls, heavy foam in the floor if a concrete slab).
- Face the house south to capture passive solar energy.
- Calculate the pitch of the roof for maximum insulation at your latitude.
- Calculate the roof overhangs to keep the sun off the windows and walls in summer.
- Have the north side with few windows.
- Triple glazed with low "e" glass.
- Eliminate thermal bridges. These tend to be where the walls meet the ground and the roof, or one material meets another. Use nylon tie bars if cladding in brick
- Use SIP panels or TJI "I" beams. The void in the "I" beams can be filled with Warmcell cellulous insulation (re-cycled newspaper). The Warmcell makes the structure air-tight.
- Have all of the south facing roof being a solar panel heating water from the sun. That is a large surface generating much heat.
- Could have a full width conservatory on the south side. Better if full width and full height. This will help but not essential. Nice to have though as bedrooms could have a balcony opening into the conservatory.
- No letterbox in front door. All doors heavily insulated and sealed (the Swedes do the best doors).
- Specify a study for home working.
Heating, Vent, Thermal Storage:
- Store the heat in a large thermal store, which would have to be sized to suit. Better have a battery of small cylinders, so if one leaks it is an easy and cheap job of replacing.
- The heavy thermal stores can be at ground level. They could even be in a separate building with superinsulted underground pipes between it and the house if need be. The thermal store should hold enough energy to heat the building over 3 or 4 cloudy days.
- Use "very" low temperature underfloor heating.
- In winter not a lot of very hot water will be generated, but hot enough for very low temp underfloor heating.
- This low temperature water can act as a preheat for DHW.
- If hot water is generated, hot enough for domestic hot water, then this water should be suitably stored for ready use rather than merging into a large low temperature water store.
- The controls will be off the shelf and all be using the odd pump here and there.
- A backup heat source can be incorporated when cloudy days extend over 3 or
4 days.
- The water system is understandable by any intelligent plumber.
- As underfloor heating is being used, bets have an extract only vent system. Heat recovery is expensive. The thermal store should store enough energy for the heating system to compensate for vent losses.
Water reclamation:
- There are large water tanks that fill from the roof available ready made. The BENELUX countries have these as standard in new builds.
- The water tank is under the garden.
- The water is used to water the garden and flush toilets, reducing water consumption drastically.
PV Cell:
- Don't bother as they are still super expensive with very long payback times. If the hosue done as above then little elecricity will be used.
Low Energy Appliance:
- These tend to be German like AEG, etc. Find out which of these is the most economical in energy and water consumption and put these in the spec.
Comms:
- Wire the place out in CAT 5 to accomodate computers and home working.
The above is the basic concept. Then, depending on site, size of house, etc, it is a matter of applying numbers to size up the thermals store, heat loss, How much energy the solar roof will generate, sizing a "very" low temp underfloor heating system, etc.
There is no sun overnight in winter, and on occasions, no wind. Have you worked out how big a heatbank?
Under floor heating, and even a small heatbank, means you should not need a huge peak heating. Possibly 6kW continuous, which would mean something like a 2kW heatpump?
However, as you say, that would not be hot enough for a shower and a heatbank. If you really can get a 10kW turbine, you could use some excess to power for an immersion heater. You'd probably want a warmbank and a heatbank.
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