“is it hot enough?” “Yes, it’s lovely”.

“room for one more?”

😉

Looks impressive, needs some green!! You’d have a field day with some of our systems, hundreds of sensors to monitor.

On the photo of of my underfloor pumps the round grey boxes are for sensors to monitor system temps, the controller goes on the DIN rail above. It’s similar to PLC process control with SCADA front end if you know control systems. Some jobs are interesting, we did the control for what I believe is the one of the largest Biomass jobs in the UK at UEA, a biomass gassification unit (a couple of stories high) produces gas for a 1.5 MW CHP unit and absorption chiller with own woodchip drier. They planted a wood to feed it! UEA Gassifier

It’s similar to PLC process control with SCADA front end if you know control systems

I dont, but damn it, if I did, my wife would sleep in another room 🙂

One of my day job projects was building a financial model for a combined heat and power biomass plant. Profit and loss, isnt nearly as interesting as kWh/tonne …. 🙂

Im planting 400+ willow stands for short rotation coppicing to help with powering mine.

Hi all, loads of info/ideas here for me to look into.

@Dobbo New place is inside the New Forest

Some pretty big systems compared to my requirements, which will be a bit more modest. I’ll definitely do as much insulation as I can I’ll definitely be doing thermal solar after that still very undecided

plenty to think about with regards making the best of the solar 1-2 stores/buffers?
biomass all to store or some direct to CH??
UFH too??? quick/slow start ups?

losts of ????????? but thanks all
I’ve got loads of time to do plenty more research/thinking

I have not read all of this but you should get a quote for ground source, no sourcing of fuel, no fuel storage, cooling as well as heating. I am not sure whether your garden is big enough for a horizontal loop but you can always have a bore hole, albeit more expensive. Link it up to solar panels to provide some of the electricity and your exposure to electricity price should be pretty limited.

GSHP was a brief thought but I don’t think there’s space for GSHP without bores which makes it very pricey + solar PV to make it work too even more expensive. Also as far as I know it works best with super insulated homes which we’ll struggle to do due various limitations (age and construction, planning, no ducting, space and cost)
also no south facing roofs to make the most of PV
South East and South West roofs means Solar water heating is still cost effective though I think!

OK I could probably get some numbers for you if I can be bothered to read the whole thread – if not super insulated then a base load plus top up could be used. Apparently when done with CHP on a commercial scheme the numbers are staggering, whether this can be achieved in the domestic market with what is currently available I have no idea.

Prof David Mackay the scientific adviser to DECC reckons there will be 20 million heat pumps in the UK by 2050.

Méfiez-vous des chiffres ronds! (beware of round numbers)

I love it when ageing professors pull figures out of their hats for dates long after they’ll be dead.

Heat pumps are great, 37% (musn’t use a round number) better than burning gas domestically for the best of them in energy terms. But, big but, they still need electricity and replacing 20 million GCH units with heat pumps will bring the grid down even at currect electricity production levels. There are houses out there that simply don’t need heating, one social housing programme featuresd on telly in the cold east of France went through last winter with no heating and a minimum inside temperature of 15°C (though I suspect less committed occupants would have plugged something in at 18°).

Renewing/renovating the housing stock would be my solution of preference.

Heat pumps are great, 37% (musn’t use a round number) better than burning gas domestically for the best of them in energy terms. But, big but, they still need electricity and replacing 20 million GCH units with heat pumps will bring the grid down even at currect electricity production levels.

I suspect that most of the early taker up’ers will be replacing oil, bottled gas and conventional electric heating. If I had mains gas heating, I’m not sure I’ve seen anything to convince me to change to a heat pump, cost wise anyway.

Stoner – are you using UK sourced pellets for your boiler? Just thinking about whether you are tied to oil prices via imported pellets relying on long distance sailing.

Has anyone got forecast figures for wood chip and pellet prices given the expected surge in demand due to the RHI?

TT – yes, Im using Verdo at the moment who source local wood (Andover and somewhere in scotland). Previously I was using Balcas (enniskillen)

http://www.verdorenewables.co.uk/Products/Bagged-Wood-Pellets.aspx

Prof David Mackay the scientific adviser to DECC reckons there will be 20 million heat pumps in the UK by 2050.

what a load of hooey.

Unless the GSHP can be linked to a renewable electrical source then it’s silly to use as an alternative to gas or biomass IMO.

I’m going to hear Prof MacKay lecture in Bristol next week – I’ll be sure to tell him you disagree!

MacKay made some ludicrously optimistic assumptions about the efficiency of heat pumps – he was out by nearly a factor of 2 when a real-world trial reported back.

As Stoner says, they’re not a worthwhile alternative to mains gas. If you don’t have mains gas, they’re worth looking at.

TT – ask him what he thinks the future optimum efficiency will be on GSHP and what he thinks they are now, and how we get from now to then.

I believe now its around 4 to 1 coefficient of performance. I cant believe it tops out much above 5.

Is anyone heating their house at present? 23.8°C here with no heating on(living in SW France has its advantages). Still on 100% solar hot water too though the next properly cloudy day will force use of the immersion heater.

not got the heating on, but the solar isnt doing the hot water on it’s own. Need pellet boiler help. Looks like at a rate of about 20kWh a day.

rainy worcestershire aint SW France 😛

MacKay suggest coefficient of efficiency of heat pumps of 3-4 in his book, those numbers are easily achievable with a well designed heat pump system and are being achieved and surpassed in this country. Cops of 5 will be achieved. Once you chuck in a green source of electricity then the numbers are exceptional.

Remind me how does biomass provide cooling?

The question is do you want to go completely green or do you would want to be sustainable if the later heat pumps make sense especially when you throw in a cooling requirement. This is obviously not a significant part of the residential market but it is in the commercial sector.

Using low-level geothermal heat, heat pumps are already at 4.5 plus but that demands a big garden or drilling. Neither being practical in the majority of British housing so you are down to air/air heat pumps. The ones sold in my local DIY store don’t beat the critical 3.3 which make them better than burning fossil fuels in a power station and suffering transmission losses. Still much better than plugging in an electrical resistance if it’s cold rather than freezing outside. The performance of air/air is lousy when it’s very cold though; dropping from +7°C to -7°C halfs the efficiency. Goggle Daikin for the manufacturer’s claims.

As for cooling, when are you going to need that in the UK? Even in SW France we can keep the house pleasant (two or three degrees above the lowest daily temperature) just with intelligent use of shutters and windows. In winter we can maintain the house two or three degrees above the highest daily temperature.

If you read my post, I recognised that the demand for cooling in the residential market was not a major driver, but it is in the commercial market where cooling is a key requirement.

As far as housing is concerned retrofit certainly makes most sense in the high end residential market where access/area is not an issue. That said for new housing it will be a no brainer as the collection loop can either be incorporated in or be under the foundations. On this basis, MacKay’s prophecy becomes realisable in the next forty years.

Air to air works but cops are not as good as you rightly say, likewise you are right on big temperature differentials, however the UK does not suffer sufficient temperatures changes for it to be a major issue unlike Sweden which has significant uptake of heat pumps.

We have disgressed from the original post but I just wanted to reply to Stonor’s balderdash.

Didn’t Mackay’s book suggest a pretty high reliance on that not so renewable source, nuclear power?

Anyway does anyone think the price of pellet will go up or down once the renewable heat incentive comes in proper?

How much of the existing housing stock has been replaced in the last 40 years? Not a fat lot. I think claiming 20 million homes with heat pumps by 2050 is balderdash but probably won’t live to find out. I went to a planning meeting tonight about a new swimming complex for my town. Geothermal with a heat pump for energy production wasn’t considered because it would have increased cost and increased the build time by 18 months (or so they claimed), and that despite perfect geological conditions. There’s no political will or economic advantage so 20 million heat pumps won’t happen. The standards for new homes now are pathetic compared with what can be achieved and therin lies the problem.

Retrofitting commercial property with external blinds that let low Winter sun through but keep out the higher Summer sun would eliminate the need for A/C in many cases.

I think pellet costs will remain competitive regardless of RHI takeup.

There’s a relatively low cost to enter the supply market (unlike new entrants in oil, coal, nuclear, electricity etc), there’s plenty of opportunity to convert waste wood into viable fuel that previously would have had no commercial value. Its also achievable on relatively small scale meaning even small timber operations can add pellet manufacturing to their business and encourage local fuel production and distribution.

Retrofitting commercial property with external blinds that let low Winter sun through but keep out the higher Summer sun would eliminate the need for A/C in many cases.

Some cases, but not many. Then you have the domestic housing stock that is woefully below the standards. It will take far more than a few blinds and shutters to improve that lot to meet the heat and cold plus increasing energy costs of the future.

Didn’t Mackay’s book suggest a pretty high reliance on that not so renewable source, nuclear power?

Lots of former nuclear sceptics are now accepting that nuclear can at least fill the gap in the immediate future. What else can generate that much electricity without just pushing carbon into the atmosphere? The electrification of our energy needs in the future is a massive problem that the current infrastructure (and energy sources) can’t cope with.

I don’t have a problem with non green sources of electricity, if you have reduced your reliance on them. That was my point of green vs sustainability.

Housing stock replacement – no idea you just have to travel by train to see how much has been built on old British Rail land.

Who said 20 million homes? I didn’t and neither did the quote, it says heat pumps.

If it increased the build time by 18 months they have found someone who does not know how to manage a project – I would envisage 3-6 months on a big project, small projects should not take that much more.

We simply need to consume less and that means homes that consume next to nothing at all, not inefficient homes with A/C units.

We’ve had 40°C plus on occasion this year but inside the house has never been over 28°C despite minimum early morning outside temperatures of 25°C. The house has an overhanging roof. There are lots of solar panels on the south facing side to absorb as much solar energy as possible. There’s 100mm of insulation between the roof chevrons, another 200mm at 90° to that before plasterboard. The roof space still gets unpleasantly warm but there’s the ceiling with another 100mm of insulation and 21mm of wood to keep the living space cool.

When we bought the house it was like walking into an oven on a hot day, it now feels like walking into a railway tunnel.

We simply need to consume less and that means homes that consume next to nothing at all

and the challenge of retro-fitting almost all of the UK housing stock to achieve that is massive. There is currently no real drive from the government, the public or the building trade – so simply consuming less is a dream right now.

Edukator – efficient building is of course the better solution but where there is a demand for heat you need to do something else.

Which is why we’ve tried (and failed)to get the local authorities to use a heat pump and geothermal for the new pool. It’s the best solution for maintaining a 50m outdoor pool at 27-29°C in Winter.

Retofitting existing homes with heat poumps is just one solution. Biomass is another but IMO the objective should be zero consumption. British houses are still being built with double glazing and no shutters. In Germany I noted houses bein built with triple glazing whilst in France double glazing with insulated shutters is the norm.

In my own home my objective is to insulate until firing up the wood burner once a day to cook the eveing meal is all the heating we need. I’m currently insulating under the floor with 100mm of recycled polyester.

ask him what he thinks the future optimum efficiency will be on GSHP and what he thinks they are now, and how we get from now to then.

I didn’t get to ask a question, but he was an excellent lecturer and wasn’t on for long enough. I know it isn’t an answer, but he did tell us about the new standards for heat pump installations – research showed results for heat pumps were too variable and not good enough, so got better standards developed:

Improving heat pump performance

Which is at least a good thing.

Rhat trench looks too shallow to me. I’ve seen them done here in France at 1m20 and Googled it to see what British installers recommend. The first result gives 4-6 feet. At least 2/3 the height of that fence then.

My polish plumbers are just putting the final touches to the heat store installation.
Stove and load charger are fitted, Oil CH boiler has been re-routed.
Should all be up and running for the cold weather later this week 😀

pics or it didnt happen geoff.

Spangly new boiler stove – 14kw to water, 8kw to room

Dinky 300l Thermal Store – shoes are models own

Laddomat load charger – not completely convinced there isn’t something a little snake oil-esque about it TBH

Panels from Kloben (don’t ask!) due next week.

looking good.

not completely convinced there isn’t something a little snake oil-esque about it

really? in what way?

looking good.
not completely convinced there isn’t something a little snake oil-esque about it
really? in what way?

Dunno really. It’s going to be useful to stop the stove acting as a heat sink once the solar circuit is fitted for sure, I just can’t get my head around the advantages, once everything is up to temperature.
I’ll report back after I’ve had a play.

It has no advnatages when everything is up to speed though, thats not what its there for.

Its to prevent chilling of the boiler through premature circulation of the water. If you chill the boiler or delay it getting up to heat then you increase the chance of flue gas condensate forming in the flue – this is corrosive stuff and ruins flues. The load controller also stops any risk of the boiler acting as a radiator in warmer weathers when the tank is hotter than the stove.

All seems to be working great and I learnt a couple of things.
1. The dial on the flu stat is really in Celsius, not Fahrenheit;
2. The stove is more than capable of running the rad and hw circuits; and
3. The boil safe valve on the heat store works 😳

any toast?