I'm confused

[canalsiderenovation]

OK, so I've been getting quotes for a water souce heat pump with the Nuenta energy blades mentioned in a previous thread based on our plans and curremt EPC, though ongoing discussions are taking place with CRT still. 

 

One thing I'm confused about in the huge amount of emails is this statement below:

 

Total estimated annual heating & hot water consumption: 21,989kWh

 

Eligible Usage (energy taken from sustainable sources): 21,989kWh x (1 - 1/4.73) = 17,340kWh

 

Total annual RHI payments = 17,340kWh x 20.46p/kWh = £3,548 a year for 7 years

 

Ignoring the RHI payments our estimated heating and hot water consumption is over 20,000 units..... So generally comparing electricity prices if I was getting an idea of how much we'd be paying on 21000 units a year works out around £3k based on currently electric prices. 

 

Is this right? I mean it's a two bed bungalow at the moment 100m2 and will be just over double and we only use £20 a month electric (electric showers, sometimes immersion but heating is oil)....  It seems a huge jump

[PeterW]

Quote is based on worst case Building Regs - so basically RHI pays you to not invest in anything more than the bare minimum for insulation standards

 

[Jeremy Harris]

RHI is a really GREAT scheme.  The worse you build your house, the more money you get paid for 7 years. 

 

Conversely, the better you build your house, the less money you get paid - in our case the RHI for a heat pump installation was going to pay us a bit over £80 a year for 7 years, yet cost us over £2000 more initially in getting an approved installation.

 

These schemes are often a bit crazy.  The Northern Irish one was so bad that people were being paid massive subsidies to heat what amounted to empty barns, as the more heat you wasted the bigger the subsidy you got paid.

[canalsiderenovation]

Yes the quote is around £21k but then we need underfloor heating, a civil engineer to dig the inlet for the blades if CRT approve. 

[PeterW]

So surprise surprise, the RHI equals the costs ..!! 

 

Walk away ...

[Declan52]

47 minutes ago, JSHarris said:

RHI is a really GREAT scheme.  The worse you build your house, the more money you get paid for 7 years. 

 

Conversely, the better you build your house, the less money you get paid - in our case the RHI for a heat pump installation was going to pay us a bit over £80 a year for 7 years, yet cost us over £2000 more initially in getting an approved installation.

 

These schemes are often a bit crazy.  The Northern Irish one was so bad that people were being paid massive subsidies to heat what amounted to empty barns, as the more heat you wasted the bigger the subsidy you got paid.

You didn't have to waste heat to earn loads you just burnt as much pellets as the boiler could handle.  You where paid on what you used, didn't matter if it was chickens that where kept warm or vintage tractors.  

[ProDave]

How much do you currently spend on oil?

 

I would be worried if my heating bill was £3K per year.

[canalsiderenovation]

1 hour ago, PeterW said:

So surprise surprise, the RHI equals the costs ..!! 

 

Walk away ...

 

The RHI is more. This is the second quote now, the first one was a little more, but different pump. 

[canalsiderenovation]

56 minutes ago, ProDave said:

How much do you currently spend on oil?

 

I would be worried if my heating bill was £3K per year.

 

We've only been here since April and actually have only just put 500litres in as the tank had just under half when we moved in and we used very little due to the hot summer so we're just having electric showers and occasional immerian heater as there are only the two of us. 

 

I think I've worked it out now as I didn't account for the Cop, so if it was say we needed 10000kwh of heat we would only actually pay for around a quarter of the electricity, say 2500kwh.... I think this is correct based on a cop of 4, which we should get with a water source heat pump. Obviously hot water on top of this..... 

 

 

 

 

[PeterW]

CoP of 4 is aspirational and usually based on perfect temperatures such as 7/35 for ASHP. Dropping the source temp and increasing the output temp seriously damages the CoP and you can end up at a CoP of 1 when the immersion’s are providing heat. 

[canalsiderenovation]

21 minutes ago, PeterW said:

CoP of 4 is aspirational and usually based on perfect temperatures such as 7/35 for ASHP. Dropping the source temp and increasing the output temp seriously damages the CoP and you can end up at a CoP of 1 when the immersion’s are providing heat. 

 

I'll do more research into this and we are due to visit the homeowner of a property who has a water source heat pump and Nuenta energy blades installed so it would be useful to know exactly what cop they are getting. 

 

I believe ASHP are the worse, I've read 2 - around 2.5, and GSHP 2.8 upwards. Water souce generally seems more favourable but I think a CoP of 3 is probably more realistic to be honest. 

[PeterW]

I can get 4+ from ASHP - don’t believe the hype of the other competing suppliers..! Also look at the TCV - GSHP need a 5-7 yearly antifreeze change that can be pretty eye watering in cost. 

[canalsiderenovation]

22 minutes ago, PeterW said:

I can get 4+ from ASHP - don’t believe the hype of the other competing suppliers..! Also look at the TCV - GSHP need a 5-7 yearly antifreeze change that can be pretty eye watering in cost. 

 

I'll ask about antifreeze change costs with the blades. There isn't a great deal of information around on heat pumps. 

 

@PeterW do you have a solar pv or solar thermal system too or is your heat pump sufficient for both? 

[PeterW]

Just run ASHP and top up the DHW using immersion’s on E7. It’s a 300 litre UVC an 165sqm 3 bed 2 bath property with a 9kw ASHP

[canalsiderenovation]

Thanks for the comments so far. A lot are in relation to ASHP and GSHP, this is a water source heat pump so I guess trying to find anyone who has had this may be limited. I'm just reviewing dates of the quote and what this includes and details. The system output is 11.50kw and details of quotation are as follows:

 

1 x Nuenta Energy Blade

Vaillant FlexoTherm 11kw

Vaillant 250L Hot Water Cylinder

Vaillant 250L Buffer Tank

 

The quote is £21525 but obviously we'd get RHI. This doesn't include controls, pipework, underfloor heating etc..... 

[PeterW]

44 minutes ago, canalsiderenovation said:

Vaillant FlexoTherm 11kw

 

 

That is a GSHP....

 

so it sounds like they replace the GSHP coils with their fancy bits of steel in the water. 

 

Could do the same with a series of coils in the canal bottom if you could get them to agree for about £500...!  

[joe90]

50 minutes ago, canalsiderenovation said:

The quote is £21525

 

Thats not a typo is it???, I paid £850 for my ASHP ?

[Ed Davies]

So this all works financially, if a) the hardware keeps going for 7 years and doesn't need any expensive replacements and b) the RHI keeps going at this ridiculous rate for 7 years as well? That could happen, I suppose.

[ProDave]

Many of us on here have concluded that the RHI benefits the installer who charges an inflated price because "they  can" as they are MCS or whatever) registered.

 

Like others I have a self install sub £1000 (by a long way) ASHP and no RHI.

 

Do some searching on the net and find some prices for those components.  Then price say 5 man days to install it. You might end up shocked a how much extra they have quoted.

[joe90]

https://www.nuenta.com/viewproduct.asp?pid=109. Metal heat exchanger about £3k. Is the canal used?, I know canal boats don’t use anchors but I would be worried about it being dredged up!, if like @PeterW  said above you used pipe, you could bury it in the mud at the bottom of the canal (with or without permission ?) and it would be safer I would have thought!

 

https://www.ebay.co.uk/itm/Green-Nylon-Chest-Waders-100-Waterproof-Fly-Coarse-Fishing-Muck-Wader/191685714599?_trkparms=aid%3D555017%26algo%3DPL.CASSINI%26ao%3D1%26asc%3D55148%26meid%3Ddfc8b5f9c9bf4442a59b5d16469d9a6e%26pid%3D100505%26rk%3D1%26rkt%3D1%26%26itm%3D191685714599&_trksid=p2045573.c100505.m3226.   Just a thought ?

Edited November 22, 2018 by joe90

[ProDave]

I doubt the CRT would give permission for anything in the actual cut. And anything you put there would only survive until it was time to dredge that section. If you have ever seem them dredging, they have basically a 360 degree digger taken off it's tracks and mounted on a barge, and it digs the stinking black sludge from the bottom of the canal into waiting empty barges to be taken away, to restore navigation depth.  Any pipe you put there would either be very vunerable, or under a thick layer of gloop and probably ineffective.

 

The bywash is different, it won't get dredged and is probably a hard bottom, kept clear by the constant flow, so if you get permission that looks a good bet.

 

I would not recommend going wading in the thick deep stinky mud at the bottom of a canal, though this one may not be as bad as some as the Llangollen has a flow to it as it is used as a water supply (you notice that going over the Pontcysyllte aqueduct)

[canalsiderenovation]

There is a separate discussion ongoing with the CRT about us creating a side inlet/pond for the blade, which is why we are doing this initial research. We did look at pond mats like Kensa but these wouldn't really be suitable due to the potential flowing water and the space they would need, where as if we can create a side pond/inlet the space is quite compact and ideal for a blade. 

 

I did price up everything they had quoted for using the cheapest prices I could find and it came to £11,152.71 so there could be definately be room to negotiate. Its certainly never going to cost sub £1000 for us. 

 

If the RHI payments more than cover the cost we'd be silly not to have it, but in my mind we still shouldn't pay over the odds as this is money we have to pay for up front to go to other things. 

[TerryE]

9 hours ago, canalsiderenovation said:

The quote is £21525 but obviously we'd get RHI

 

Like @joe90 I almost shit a brick at that.   OK, I have a passive-class house, but £21½K would pay for my heating system and all of our energy needs for least the next 12 years at current prices. And my house is about the same size as yours post extension.

 

If Canal-side means (as it does near us) that you've got a solid 2 brick (as in 9") wall profile and absolutely appalling U-values that you can do little about, then this is just a price of living in a picturesque canal-side cottage.  However, as you are doubling your area from 100 to 200 m² then you must be building the extra footprint to at least current BRegs and converting current external wall to internal, as well as insulation the entire roof void to BRegs? 

 

It just seems crazy to me to consider paying £50K over the next 10 years for your heating needs. OK RHI makes a dent, but what happens when this canned like many other incentive schemes or if you have key equipment failure?  I would really do some reasonable energy estimates and how to mitigate your costs.   As Peter says ASHP will almost certainly work out a lot cheaper and simpler.  Ditto a conventional Gas boiler, if you can get gas. 

 

       

[canalsiderenovation]

6 hours ago, TerryE said:

 

Like @joe90 I almost shit a brick at that.   OK, I have a passive-class house, but £21½K would pay for my heating system and all of our energy needs for least the next 12 years at current prices. And my house is about the same size as yours post extension.

 

If Canal-side means (as it does near us) that you've got a solid 2 brick (as in 9") wall profile and absolutely appalling U-values that you can do little about, then this is just a price of living in a picturesque canal-side cottage.  However, as you are doubling your area from 100 to 200 m² then you must be building the extra footprint to at least current BRegs and converting current external wall to internal, as well as insulation the entire roof void to BRegs? 

 

It just seems crazy to me to consider paying £50K over the next 10 years for your heating needs. OK RHI makes a dent, but what happens when this canned like many other incentive schemes or if you have key equipment failure?  I would really do some reasonable energy estimates and how to mitigate your costs.   As Peter says ASHP will almost certainly work out a lot cheaper and simpler.  Ditto a conventional Gas boiler, if you can get gas. 

 

       

It's not a cottage, it's a 1970s bunglaow on a half acre plot and as planning is for an extension above and out so the roof will be coming off and the whole thing needs rewiring, replastering, new windows, doors etc, etc, it's not a solid 2 brick, nor an old canal cottage, it's a rather strange mid 1970s bungalow and has cavity wall insulation already, but yes of course everything will need building regs. We can't get gas over a canal bridge, if we had gas I wouldn't be looking at any of this at all, but we don't. We have oil.

 

ASHP is our backup option. Either way we'd be paying someone to do it so it's always going to cost more than people who have installed it themselves, when the equipment they have quoted is just over £10k, its not going to be any less. That said we will be getting more quotes and doing some ongoing research into both and now have two people who have the blade technology installed that I can visit.