[Closed] Biomass/Solar eco experts, advice sought. Stoner +?

You should seek the opinion of a medical professional.

😉

oooh lots to talk about. Do feel free to email me off forum to if you have any other questions.

Im no expert, but have learnt a good deal through my experiences.

First of all: sizing.

Large biomass boilers dont cost a whole lot more than smaller ones and you will get best performance ragging your boiler flat out for as few an ignition cycles as possible and using your buffer (thermal store) to achieve this. To this end sizing isnt as important as say for a combi gas boiler that produces heat on call.

Id recommend learning about u-values, heatloss and vent loss calcs and having a stab at what kind of energy your new house is going to need after youve done as much insulating as possible.

from that you can work out what kind of thermal store size would work best during winter.

The great thing about the thermal store as you mention is that you can swap the call for heat source from gas to biomass at a later date (hell, if it isnt in the way, you could even leave the gas boiler in situ as a back up 😉 )

Pellet fired is probably the way to go for simplicity. There';s lots of suppliers out there now, and buying 10Kg bags or blown loads is easy. My neighbour has a 4 ton bag into which deliveries are blown. I have a store in which I can store about 2-3 tons of 10Kg bags. I manhandle these bags in 600Kg at a time to my boiler room. But Im young and fit. To make life easier I could convert my store into a 2t ply tank and buy a vacuum transport system to move the pellets 150Kg at a time into my "week" hopper next to the boiler at a flick of a switch.

If you can factor in pellet storage right next to the boiler, then you can just use the supply auger, for a simpler system (vaccuum transport is pricey)

Chip is not the same as pellet. Its wetter and less efficient but your fuel source is more versatile if you have access to waste wood and a chipper, but I reckon longer term, youll find pellets a more reliable, if more expensive energy source.

...

hmmmm this is going to be a very long post. SO much to cover. You should really come and visit and I can show you mine, and my neighbours set up (his is very whizzy, techno complex and expensive, but theres lots to be learnt from his system design) mine's more basic and low tech (I can service and fix my boiler - no need to pay engineer fees!)

ball park figures:
5k for boiler, 1.5k for thermal store and solar coil
1-2k for solar thermal
1-2k for UFH

EDIT: BTW, your plans are almost identical (but about 50% for sizing) to mine: biomass of pellets with logs, + solar thermal + UFH + radiators upstairs. WIll psot pics to illustrate in case you havent seen them before

UFH manifold. UFH downstairs controlled by single thermostatic controller in middle of ground floor. Each of 6 zones is balanced to provide even 18 deg heat across whole of 1,500 sq ft ground floor (all open plan). Water comes from middle (50-60deg ish) of thermal store and blended with UFh return down to 40ish.
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UFH Laying out prior to screed (i laid it out and installed the UFH, and paid for others to screed)
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[s]Nuclear reactor[/s]Boiler being delivered
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720l Thermal store
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Low volume aluminium radiators upstairs. Controlled by a single thermostatic timer located in upstairs corridor. Draws hot water (mixed with return water back to 50ish) direct from boiler (not thermal store), each rad has its own TRV
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Biotriplex by Jaspi. LHS for logs in furnace, RHS pellets (red box on front is burner). "Week" tank will take about 180Kg. This time of year will last for 40-50 days +, mid winter -10degs, lasts about 5 days. Can also see expansion vessel for system. 1.5Bar max (which is very low). But theres about 1000litres of water in the system. You can see the radiator flow and return coming out the top of the boiler.
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Thermal store.
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Wood store, pellets kept on pallet. ABout 25-30ft from the week tank. Takes about 40 minutes to transfer 60 bags into boiler room.
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moved this lot in the other day, will last until well into november

I had sort of used your set up as a bit of a template tbh backed up by a fair bit of reading on the net too. I've followed and bookmarked your previous threads already for reference

I'm only at really initial stages at the moment we don't even move in until next month but will want to get planning rolling asap as the national park makes things a bit complicated.

I'll certainly email you when I'm further down the line and thanks for the offer of a visit too, really kind, it'll be really helpful before I get head on into it (sometime next year probably).
Where about in the country are you?

Im in malvern. Bring a bike* and a notebook.
welcome to stay over if it's a long trip and grab a ride etc.

*Although I have a spare 29er if you fancy coming by train! 😉

BTW, the other thing to consider is what geoffj on here is lookg at, which is a log burner with a boiler on the back and linking that to the thermal store via a load charger.

oh btw I was thinking of using the pitched roof space for pellet storage with a hole and shoot to reload the week ish sized hopper
That way it'll be easy reloading and not too much hassle to get it blown in there

All sounds great I'll be in touch
cheers

like the sound of that.
Blown loads can be delivered over at least 30 metres IIRC.

There are some issues with combustable fuel storage in a house though, but Id need to read up on it, not sure if it applies to pellets.

Dont forget 2-4tons of pellets is quite a load on ceiling joists - youd need to reinforce.

Don't suppose your doing the Bear Bones 200 next month are you?

Bear Bones 200

guess not then

[url= http://www.bearbonesbikepacking.co.uk/index.html ]200k Bivy thingy, mid wales, by guys that did the welsh ride thing[/url]

Ah. no.

BTW - Part J (Fuel storage) doesnt apply to solid fuels.

I'd say stoner has it covered.
After a bit of looking around, I'm getting my solar kit from Navitron - http://www.navitron.org.uk/category.php?catID=71 they have a forum too.

I got my cylinder from Newark Copper Cylinders, so I could customise the type and location of the coils ( http://www.newarkcoppercylinder.co.uk/)

My thermal store will have feeds from a multifuel boiler stove, oil fired central heating boiler (already in) and the solar evacuated tubes. Unfortunately, we can't do underfloor heating, so everything is sized for higher temps using (new but) traditional rads.

I'm hoping that the load charger ( http://www.stovesonline.co.uk/wood_burning_stoves/Load-units-and-laddomats.html) is going to help to maintain stratification and stop the stove running as a radiator in the summer with the heat from the evacuated tubes.

Its currently all sitting in the garage waiting for my polish installer friend to get started.

I think the RHI payments on the solar thermal part are probably going to work out at 300-350 per year for me. The RHI payments for biomass are 7.9p per kwh - there is a calculator you can try here http://www.biomassenergycentre.org.uk/pls/portal/url/ITEM/9DFC29E3FE404C21E04014AC08044E0E

There may be an issue with keeping the gas boiler if you want to register and claim RHI.

If you insulate well enough, you don't need a biomass boiler, or any kind of central heating system for that matter. You should also consider mechanical heat recovery and ventilation.

Best place to ask these sorts of questions is here: http://www.greenbuildingforum.co.uk/newforum/

If you insulate well enough you don't need ... any kind of central heating system

not really an option in an existing building. If you were constructing a passivhaus from scratch then possibly. But not a 150yr old, draughty slate cottage in the new forest.

"not really an option in an existing building. If you were constructing a passivhaus from scratch then possibly. But not a 150yr old, draughty slate cottage in the new forest."

The OP suggest that lots of work needs doing - the thought occurs that if (for example) all the windows are to be replaced, floors taken up etc, living without central heating is a possibility. But you're right that it wouldn't be easy.

In any case, given that the house already has a gas boiler, and is to be insulated, I can't see how biomass is going to be cost effective.

I agree to a point. for at least the next 10-15 yrs i expect mains gas to be the most economical fuel if you can get it. but adding a thermal store, with solar and log boiler isnt a bad idea. its nice to have some energy independance as well.

Ground source heat/cooling pump? Warms in the winter and cools the house in summer. Is that not worth a look? I know sod all about it, just thought it may be a simple one to put in to reduce the load/size of your boiler. Suppose it depends on how much land you have and whether digging up your garden is an option.

thanks Geoff some useful resources there I'll have a look into them properly later

Ransos I will do what I can with the house with regards insulation but it's an old place not a new build + it's in a national park so I'm a bit restricted with what I can do certainly externally I'm not sure I can get away with no direct heat sources. I will have a look though

cheers

Im not a fan of GSHP because theyre still pegged to electricity in terms of energy cost which is only going to go one way. But ASHP with a wet CH system would be a good replacement for night storage heaters for example.

Gardens is an ok size 12m x 22m but that's probably not big enough is it?

cost is still a major factor + I'm not sure how effectively we'd be able to seal and insulate the house up to that level

as I said I will probably initially do the solar and thermal store and get everything ready but re-use the gas boiler that's there for the moment and just swap the Biomass in when funds allow
Yes cost is a factor but the environment is too I accept pellets may cost a bit more at the moment but as Stoner says that should change Gas is only going one way

its nice to have some energy independance as well.

This is my main motivation. Last December, there was a 3 week delay for oil deliveries and when they finally were able to supply, the lorry couldn't get to our neighbours because of the snow.

Being on oil, looking at alternative / supplementary technologies is a no brainer for us. I'm just surprised at how many folk in our village are mindlessly replacing oil fired combi boilers, without investigating alternatives.

if you use the average kWh consumption figure and british gas tarif structures, the weighted average cost of gas fuel is about 4.9p/kWh. At 90% efficiency for an A rated combi, that's a real heat generation cost of about 5.5p/kWh

My pellets cost about £259/tonne, with an energy density of about 4.9kWh per Kg, 5.2p/kWh
At 89% efficiency in my pellet boiler, thats 5.8p/kWh.

With heating oil prices at around £300/500 litres and oil energy density of 10kWh/litre, oil boilers are a little more efficient at around 92%, so cost comes out at 6.5p/kWh

Those calcs rather surprise me. When I first did these figures 18 months ago, gas was loads cheaper, and oil was the second cheapest - something like 3.5p gas, 4.4p Oil and 5.5p wood. 😯

Boiler mainly and initial set-up costs are much higher than a std Gas/oil system and many think very short term, I think that would put a lot of people off + effort of keeping it running
Gas is certainly fit and forget, and oil's not far off, biomass is more effort

I don't think a lot of people in the general public know much about biomass either. I didn't until I saw Stoner's threads on here and went looking for more info

Stoner with your boiler being dual fuel how does that bit work?
what I'd ideally like is it to use logs if they're there, then pellets if not. Is it that clever?

mines quite simple. Before the tank temperature has fallen to the ignition trigger point (say 55dges or 65 degs) I build a fire in the furnace.

Once a starter fire is going nicely, then you load the furnace with neatly stacked logs - can take about two large armfuls. Let it get going properly and then shut it down. It will burn all morning and can raise about 500l of water by about 20degrees. The pellet boiler wont fire until the temp gets down to the trigger point.

You dont light the fire if the tank is showing 85degs though. Theres a supression system that kicks in at 90degrees.

Might have a pic or vid somewhere...hang on....

here we are, this shows the starter fire on the grid at the bottom of the furnace. I now load the logs in a neat stack on top of the fire.

The fire burns from the bottom up, so it can look after it self. You can control the air flow through the wood stack or through the bottom, it then goes through the throat at the bottom of the furnace (where the ash pan is) and then up into the boiler heat transfer chambers.

29er: I appreciate you're restricted because of your location, but consider internal insulation: I had it installed in one of my bedrooms and the difference amazed me. Underfloor insulation is well worthwhile, too.

A well insulated house with MHRV, and a wood burner with back boiler? It could connect to the thermal store...given that you have mains gas, I honestly think that a pellet boiler is overkill.

As a general point, we have commissioned the installation several biomass boilers at work (schools etc) and whilst they reduce carbon emissions, the economics don't really stack up. You'd also need to be pretty sure that the RHI subsidy is going to continue for many years.

I'll try and do as much internal insulation as I can but I really don't want to have to loose any space from the rooms, the 2 bedrooms in the part of the house which will be remaining are only 3.5m x 3m so not big it's not a massive house so I want to make the most of the space available.

I will look at the numbers in greater detail, Biomass is just a thought, back boiler like Geoffj's is also an option too

Insulation, Thermal store and solar are 100% on the list though

cheers all

and of course UFH without floor insulation is just nuts 😉

BTW - you may want to keep in touch with Marin_Maketh_The_Man on here as I believe he's venturing into the world of smoke and fire too.

The UFH section will be a new sub-base with insulation which I'll do and as you did get the pro's in to screed it, it'll probably have engineered Oak floor/tiles in the kitchen

So the log section is a manual load and start up, not to much hassle at all then

I'll have a search for Marin_Maketh_The_Man threads too

So the log section is a manual load and start up, not to much hassle at all then

No. Its quite therapeutic in the morning, after coffee, to go make a fire for the day's hot water. It's the equivalent of the "free" summer solar energy.

I'll have a search for Marin_Maketh_The_Man threads too

Dont think he's done a thread yet, just contacted me off forum. But he's in much the same position as you, and since you'll both be doing research 18 months after I did, you may find you each have more contemporary info to share than I can. He has a pm email.

EDIT

Oak floor/tiles in the kitchen

NEVER wood floor in a kitchen 😉
And stone is by far the best thermally performing floor material for UFH

Some very good Swedish products;

http://www.allweatherheating.co.uk/

No, not wood in the kitchen, tiles! wood in the lounge and dinning areas

The Wife's not keen on tiles/stone throughout downstairs, something about kids falling over, wood floor will still hurt

Kids, like snooker balls, bounce very well on limestone 🙂

1,500ft of limestone tile throughout the ground floor which includes the boys play area. Theres a few rugs, and one in the middle of their play area has a padded underlay to make it more comfortable to sprawl on.

It makes it easier to keep the house clean (sweep and mop) when mud gets in.

(this isnt quite how its laid out now, with rugs and sofas etc, but you get the idea of the floor)
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I'll work on her on the floor.

Keeping mud out shouldn't be too much of a problem
The plan is to to have the boiler room on the back of the garage but also a shower room and toilet. So when I come in from a muddy ride/run or from working on bikes etc then I can get washed up out there before coming in

All part of the Maximising living space.

The national park planning rules are very rigid and will only allow for a 30% increase in floor area in the house (should get us 121sqm), but we have a number of small "outbuildings" (garages, sheds, aviaries, copper house and coal store) that we can knock down and re-used the area in one big garage/shower room/boiler room/utility/office thingy. It'll be to the side of the house with a path in-between with 2 doors facing one another to get between the two, we'll probably have the path covered too

oh forgot to say I'll probably have a go a doing a rain water harvesting system too. usual for toilets washing machine and outside taps. I was Looking at a 2.5-3k litre system

these are the plans anyway, need to get them all drawn up and pass planing but reading the rules I think we should be ok

oh forgot to say I'll probably have a go a doing a rain water harvesting system too. usual for toilets washing machine and outside taps. I was Looking at a 2.5-3k litre system

I hate to say it, but rainwater harvesting is probably the most uneconomic eco adaptation you can do.

I plumbed the barn for rainwater supply to 2x toilets, DW and WM. But the tank and water pumping system (you need water reg approved mains bypass controller etc) came to about £2k+, which for a saving of about £50pa on the water bill just made no sense.

So I didnt bother.

Not read it all as just getting going after a bit of a heavy night!

We've got a log burner we inherited from the previous house owner, he has a joinery company and got unlimited wood to run the place for free, we've been coming to grips with it and it's a bit love/hate. It does tie you down due to time lags in getting the thing started and up to temp if you've been away for a few days. The system wont start to supply heat to the underfloor until the thermal store has 45ºC which can take a few hours, then underfloor is not instantaneous either so in the middle of winter it can be frustrating.

Log prices aren't cheep, and the quality varies a lot, we use a local supplier and it's gone up to £50 a dumpy bag it's claimed to be hardwood but it's a mix, some of it doesn't have much substance but it is well seasoned.

We have a good size multi fuel stove so we tend to rely on that mostly, we've go 2 tons of coal coming today, that gives an idea of what we tend to use out of preference! We got a price to replace the log boiler to wood pellet and it would cost £14k (ouch). That's Windhager which is an expensive make, all the room controls communicate to the boiler using LON network etc...

Some pics.
Boiler and 1500ltr accumulator (thermal store).
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Underfloor pumps and valves.
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Part of log store with dumpy bags in front waiting for the coal man!!
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Expansion vessel needs to be large due to thermal store.
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Edit:
Also got a ton of these coming tomorrow, £250 @ 5Kwh/Kg, see how they work out.

[img] [/img]

may just do a simple underground tank and a simple pump for watering the garden. so just a big water butt

a friend got an old oil style tank, buried it and added a pump to water his veggie patch. cost about £200 I think

that's an ace set up dobbo.

Similar to my neighbour's (all whizzy controllers and logic gates)

Im sure there would be a way of replacing the log burner with a simple pellet burner that neednt interact with the controller system in the same way?

And is there really not a pellet burner adaptation that can be made to the log burner?

keith - yes that wouldnt be a bad idea. you can use a 12v bilge pump to a trickle irrigation system, powered by solar too 🙂

cheers dobbo

I think my needs are a little more modest from yours and Stoner's from the looks of your set ups. So the time to raise the temp of a much smaller thermal store should be a bit better + pellets have an a lot more autonomy so hopefully shouldn't be too much hassle

£15K Ouch!!!

keith - heating the store from cold takes time, but you never really do that. During winter you dont let it get below, say 60degs at the top before the boiler kicks in again taking it up to 85degs. Youre never without hot water and waiting for it.

Also UFH should be left on for long periods but lower temps. It doesnt cycle well as there s lag in heating up the slab. I have mine set to 18degrees for most of the day (as I work from home) it doesnt take much energy, but letting it go cold during the day and have it try and fire up again in the evening to 20dges say would take a while. Quick extra heat comes from the log burner anyway.

There's no converter for that boiler, the boiler set up would be so different I expect. I'm also looking at maybe adding a ASHP that would feed into the underfloor header and would isolate the thermal store via a 3 port control valve, it would monitor the underfloor pumps, if one is started by a zone it would close a relay and start the ASHP thus all being automatic which is my main aim now. If the log boiler was running or heat in the thermal store that would have priority and the ASHP would only start if no other heat is available. If that makes sense!!

ASHP

still using elec to heat your home. Naughty Dobbo!
🙂

Also UFH should be left on for long periods but lower temps. It doesnt cycle well as there s lag in heating up the slab. I have mine set to 18degrees for most of the day (as I work from home) it doesnt take much energy, but letting it go cold during the day and have it try and fire up again in the evening to 20dges say would take a while. Quick extra heat comes from the log burner anyway.

Very true, if you have a heat pump setup it is common to run it 24 hours a day in cold periods but then reduce the flow temp down to around 35ºC.
The 1500ltr thermal store seems to last for a surprisingly short time 🙁 My problem is we have to have cold starts fairly frequently.

still using elec to heat your home. Naughty Dobbo!

The 1500ltr thermal store seems to last for a surprisingly short time My problem is we have to have cold starts fairly frequently.

thats odd. Mines only 720l and will last 4-6 hours or so in winter (20degree loss before recharge)

Why the cold starts out of interest?

Mines only 720l and will last 4-6 hours or so in winter

I was hoping 1500ltrs would last a day+ 😆

Why the cold starts out of interest?

We live between 2 houses.

We live between 2 houses.

http://www.smscentralheating.co.uk/central-heating-control

I was hoping 1500ltrs would last a day+

Ive heard of a scottish biomass powered underground store of 20+ tons of water, heated with a something like a 75kW boiler. Lasts a week 🙂

Insulate properly first then work out what you need. This may be a lot less than you originally thought. A guy round the corner fitted a fancy new gas boiler with lots of radiators. He then got on with insulating and fitted a wood burner. He's now realised that firing up the wood burner once a day is pretty much all that's needed. Most (if not all) of the radiators are unnecessary and the boiler is way oversized.

insulation wise what options are there? That will not rob the room of space. other than:
-decent windows/doors (low U thermal glass etc)
-Cavity wall insulation
n.b I need to be careful with this as 100 year old porous bricks can be a problem with the wrong type
-loft/roof insulation (must remain Slate I believe)

part of my problem is to do my extension I need to knock down the dodgy old extension where the boiler is currently housed. and i don't want to have to go back after wards and put more pipes etc in /not sue some
so suck and see isn't that easy

If you are planning on re-doing any plasterwork, then you should consider insulated stud or insulated plasterboard (polystyrene backed). You would lose, say, 50-75mm of perimeter depth but gain loads in U-value.

Its not ideal as your thermal mass is still on the outside of the insulation. If I were to buy a gopping 1950-70s house I would take the roof off, re-do the roof line and externally clad in local timber with insulation behind it. Deep window/ door reveals, but all the thermal mass would be in side the insulated envelope.

Something like silver TLX insulation can add loads of uvalue to even 50mm of kingspan (et al) in a roof where space is tight. Ideally your loft should have 300mm of mineral wool or equivalent.

this is TLX over 50mm of xtratherm (hidden) just where it meets 100m of mineral coming p the cavity wall. We were short of depth to work with in the pitched section of roof before the ceiling comes across.
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allow for 100mm of depth of insulation above your concrete slab and then a further 75mm of screed (which envelops your UFH pipes) on top. Pipes clip down to insulation:
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this is a cut away of the screed where we cut out the insulation to make a concrete pad for the thermal store so you can see the depth over the insulation beneath
[img] [/img]

small rooms so extra studs internally is something I really want to avoid

roof line can't be changed, oh thinks it's about 1910-1920's

window reveals even have to stay the same and even be replicated in the extension too from what I've read of the planning rules

oh we'll also be re-doing all the lights to low power ones, probably LED

only had few conversations with planing so far but it's pretty restrictive where we are. Don't want to butt heads with them for ages so will try to work as best we can with them to get what we can, space and energy efficiency.

oh we'll also be re-doing all the lights to low power ones, probably LED

build yourself a rig (better still I think I still have one I built for me) and buy a range of individual models to test. You really need to be comfortable with the colour and shape of the lamp output before you commit to 10s of them at £20 each.

There's over 100 in the barn, 3 different models ranging from £3.50 to £20 each.

So Stoner you went with Plastic for all your plumbing then by the looks of it?
plain plastic or the Alloy lined plastic stuff?
seems so easy to work with compared to copper and soo! much cheaper
I just worry about the fixings a little
and what's all this about air ingress is that through the pipe itself or the fixings?

My Bro' is a sparky and is doing a lots of LED stuff now
so should be able to get stuff to test no prob's

I'm off now, will be back Monday, off to do a [url= http://tinyurl.com/66bxzd5 ]140m Run/Bike/Kayak C2C[/url] this weekend

yep Hep2o thought except for radiator tails and in the boiler room obviously.

Plain 15mm and 20mm for hot and cold and barrier stuff for the radiator and UFH feeds to minimise oxygen absorption in the indirect heating circuit.

Great stuff to use as I could do a lot of it, with no prior plumbing training, and no copper skillz needed.

we pre-holed the joists to run to sets of services (wet and sparks) down the length of the building. It means in future if I ever need to drop in, I know to the nearest 100mm where they are anywhere in the house.

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and then they break through into the boiler room

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EDIT have fun then.

I'm not so sure about this "insulate the outside" lark. Having a house that is more responsive to heat input is better for us and may be better for the OP. The reasons:

We go away for the weekend and holidays in winter. When we get back it only takes an hour or two with the wood burner to get the place cosy. With plaster and brick walls it would take several hours.

For equal u the total energy bill is smaller if you accept lower temperatures for some periods of the day. Heat loss is proportional to temperature difference and running a lower temperature difference cuts losses. In our case we light the wood burner at about 17:00 and by the time we are sat watching the news on TF1 at 20:00 it's about 20°C. Temperature then declines through the night to about 16°C when it's cold outside. I'm quite happy with that through the next day and it rarely drops further thank's to sun through the windows and appliances being used.

The percieved warmth in a room depends on the wall material. Stone feels colder than wood when you are standing next to it for the same temperature. In French it's called "l'effet de paroi froid". Insulating the inside with wood makes a room feel warmer than it is.

In older houses with damp walls wood on the inside protects you from the damp whilst doing nothing to stop humidity being driven to the outside of the wall and away. Waterproof renders and polystyrene keep humidity in as well as the rain out.

Just had a chat with my other neighbour who's tied to oil. He's just taken delivery yesterday of 1,500 litres for £1,000 = 7.2p/kWh @ 92% efficiency! My previous calc (6.5p) was at £300 per 500L.

He needs two of those a year 😯

[url= http://www.boilerjuice.com/heatingOilPrices.php ]Boilerjuice[/url] is reporting it at 57.5p per litre

[img] [/img]

Still expensive though and come the snow it'll rocket.

He might have been rounding up in his head, but was calling it 60p/Litre.

Just had a bit more of a look through the earlier post as I'm a bit more with it today!

I like your set up Stoner, that's a dual fuel boiler then, logs or pellets, nice touch. I wonder if you need to use the thermal store with pellets as they can be regulated so much. The option I was looking at would be to have a large remote pellets store blown filled then use a vacuum feed to the week tank that built in to the Windhager boilers. I was planning on removing or valving off the thermal store as the boiler can modulate much like a conventional boiler.

The other option is to have a solar coil fitted to the thermal store, it has a blanking plate for the coil to be fitted.

I'd half though about removing the half the roof of our workshop/shed and putting thermal solar on it to feed the tank. I'd like PV but the shed not south facing, it's either west or east 🙁 The house is south facing but I don't want solar on the roof.

Our shed:
[img] [/img]

Here is a [url= http://www.windhager.co.uk/public/frontend/downloads/systemdesign/thebiomassguide.pdf ]Biomass Guide[/url] it's about Windhager products but still interesting to see system configs.

By the way what national park are you in 29erKeith?

[url= http://www.greenbuildingforum.co.uk/forum114/?CategoryID=22 ]Green Building Forum[/url] Another useful link to a good knowledge forum.

[url= http://www.boilerjuice.com/includes/echoPriceGraph.inc.php?d=730&s=XL&min=0&max=0&avg=1&a=1&ot=1 ]Oil prices for the past 2 years[/url]

Well it was up to 73p last winter (6.9p per kWh 8O), and I expect it to go the same way again as soon as it gets cold.

I should try and work out how much my firewood costs me.
This year I've had to buy a new saw and PPE, so probably spent £300 and collected about 15 m3 of hardwood.

EDIT to correct mistake
Volume of wood 15 m^3
Volume as Cord 4.41 (1 cord= approx 3.4 m^3)
BTU per Cord (millions) 30 (Oak / Beech Mix
KWh per m^3 2585
Total Value 38768
Efficiency of OCH 92%
Efficiency of WBS 75%
Energy in 1 tank of oil 12000
Converted energy of 1 tank of oil 11040
Converted energy of wood collected 29076
There for 15m^3 = 2.63 1200 tanks of oil
Price as oil £1,896.25
Cost to me this year £300.00
Effective price per kWh £0.0103
Smugness coefficient at not having to ring oil supplier 1000000

Stoner - it'd be good if you could check the maths 😀

Id recommend using a thermal store with any biomass/solar set up. My neighbour doesnt have one (except for a small buffer in his boiler) because apparently its so smart it can hit efficiency even when cycling. His solar has a separate tank though.

Mine all goes to one place. Just seems so much simpler. I even have space for at least 2 mor eheat sources if I wanted too, and whilst I have a backup (very backup, logs would come first! 😉 ) immersion heater in the boiler tank, I can also fit two of them to the thermal store as well.

In fact if I ever fitted PV, rather than sell to the grid for a paltry 3p/kWh (not the same as FITS remember, you still get those no matter what you do with the elec) I could use a 12v immersion coil as an energy dump for surplus elec in the thermal store 🙂

You can mount solar thermal vertically, on that south facing wall where the round window is BTW.

Vaccum transport systems, as far as Ive been able to find out, seem very expensive - about £1000. Im sure an old henry vacuum cleaner could be adapted to do the job for a lot less...or if more puff required a commercial unit.

geoff - will do in a bit - got to go out.

PS - dont trust Boilerjuice figures.
http://heating-oil.blogs-uk.co.uk/dcc-claims-profiting-boiler-juice-price-hikes/

You can mount solar thermal vertically, on that south facing wall where the round window is BTW.

I think the thermal store will stay and only be isolated if ASHP comes in to the equation. £1000 is what I was quoated for the kit, to do it with pipes etc.

Did you do most of the build yourself or project it, must have been great fun to do, design and see progress.

I did the design and managed the project, whilst also jobbing on site 5 days a week for my builder mate who did the tricky buildingy stuff.

I installed the UFH and solar thermal. I worked with a specifier and plumber and HETAS guy on the boiler installation though.

It was a fantastic project. And I learnt huge amounts - mostly how not to be scared of having a go.

Solar thermal would make a better pergola roof as you have light pass through between the tubes. PV panels would block it all out 🙂

this is mine:

[img] [/img]
more [url= https://picasaweb.google.com/bakehousebarn/SolarProject ]here[/url]

Thats a pretty impressive setup, having them as a ground mounted array gives you the advantage of exact angle and and direction as well, plus you can have a large m2. To make it worthwhile for heating you need a good amount.

Quick fire questions!!
Is the feed to you thermal store run in 22mm?
What distance is it?
Do you loose much temp on the run?
Do you get RHI for it?

To have PV it's not worth it unless you're pretty much facing south, not so sure with thermal as the install costs are that much lower.

[i]Is the feed to you thermal store run in 22mm?[/i]

DN20 insulated steel flexible tubing. 22mm copper at manifold and in boiler room.

[i]What distance is it?[/i]

17m + boiler room runs of about 3m

[i]Do you loose much temp on the run?[/i]

No idea, but I run the hysteresis quite wide, so it starts pumping at +8 and off at +6 so that the pump isnt running when theres a risk of moving hoter water out to the manifold than Im getting back in.

[i]Do you get RHI for it?[/i]

No. The quote for having an MCS certified installer stick an MCS certified system in was 3.5x as much as mine cost which wiped out the benefit of the RHIs.

I had a thread covering most of the detail, here:
http://www.singletrackworld.com/forum/topic/solar-water-thermal-panels-the-installation-w-pics

I'll have a read through that thread with a cup of tea!!

If this is covered in that thread say, but, when you have the boiler running and heating the thermal store how do you prevent it filling the thermal store down to the bottom down to the solar coil? Else you'd be just having a small gain from the solar or even a -ve.

Separate tanks. (with a 😉 for Stoner). In winter I use the solar tank as a feed for the main tank; a pre-heater. In summer everything feeds direct off the solar tank bypassing the main tank. I've also plumbed the washing machine so it can be run off either tank during the fill cycle and switched to cold water for the rinse.

If I were Stoner, I'd fit a 300l tank with a coil fed from the solar panels plumbed so that by opening and closing a few valves (Five in my case) either tank can feed the domestic hot water circuit direct or the solar tank can be used as a pre-heater for the thermal store.

I like the idea of Ed's pre-heating tank but I dont have the space now.

I rely on stratification to maintain as low a temp as possible in the thermal store.

In summer, it's not a problem as the boiler is off, but when it's running turbulence from the 85deg hot water inserted at the top of the 2m high tank raises the bottom temp to about 50degs. Which is not great for solar capture. It does still work, because my array manifold easily gets to 60+ degs in autumn, but later in the season it may not be so great. Of course as long as the energy absorption of the array exceeds its losses, then eventually there will be a positive temp differential between the Solar manifold and the tank - so it should always eventually work , but the higher the temp, the higher the losses.

This autumn I am working on various temp settings in the boiler to find the most efficient one.

Will report back in a few months when I think Ive got it.

That was why I wondered, the pre heat tank is common in larger commercial jobs, here is a layout of a recent job:-
[img] [/img]

Good if you use a lot of hot water. But for heating systems I suppose it's harder to make the most of the solar water during the winter for heating, as the thermal store will have heat.

Diagram makes a lot of sense.

SO do you fit many of these systems?

I do Building Management Systems software and graphics that control large commercial systems the Olympic Velodrome, large district heating projects, PFI stuff, nothing domestic. Nearly all jobs have biomass, CHP and solar nowadays with a strong slant on energy monitoring, metering and analysis.

a strong slant on energy monitoring, metering and analysis.

now that Id enjoy.

*pushes NHS glasses up nose*

This is just some of the analysis Ive been doing on my system
[img] [/img]

My analysis amounts too "ughhh, brrr, the shower's cold, time to start sending the water through the main tank and switch on the immersion heater". It hasn't happened since the Spring but soon will as the sun drops in the sky.

Madame is in the shower as I type, "is it hot enough?" "Yes, it's lovely".