RHI - Have the cowboys arrived in town already ?

John_Pierpoint

I don't speak German, but I understand that the Germans, as well as publishing figures on how long cars last (as do the Swedes, presumably from their MOT test database) the Germans publish figures on heat pumps. These figures suggest that the mean time to failure (ie life) of a German ground source heat pump is 20.5 years.
If someone can find the actual source for this hearsay evidence - please post a link.

I have a an Italian "Indesit" fridge (*) that dates back to the mid 1970s so I can believe that a heat pump could last that long - if the electronic "brain" of a modern heat pump would be up to the job is a mute point.

Here in Britain you would be hard pushed to find heat pump installations that are 20 years old, failed or otherwise.

The design of the property will effect the longevity and perceived performance of the heat pump.

In a superbly insulated German home, the pump can quietly do its own thing in a building that is permanently warm. Constantly being forced to "cycle" (turn on and off) is the best way to reduce its life (knacker it).


(*) OK I know it probably makes sense to replace the 35+ year old fridge on energy saving pay back terms. Though it was bought shortly after the UK adopted the Continental 600 x 600 mm standard for kitchen equipment, it is 1350 mm high. It is partnered by a chest freezer (Austrian) in the garage, also still "going strong".

Unfortunately its position only allows a headroom of 1910 mm and large modern fridge/freezers seem to be designed to a 600 x 600 x 2000 mm modulus.

[My son recently acquired a new Bosch of these dimensions, where the packaging betrayed evidence of "flood damage", at a very advantageous price - he and his family have not yet displayed symptoms of dysentery ]

John_Pierpoint

Trying to get back on thread...........which I think is "Are the civil servants making the carbon saving subsidies so complex that a rational consumer won't consider them and the "cowboys" will rip off naive consumers, stimulated by the government's advertising spend" ?

I am somewhat confused by the clause in the RHI deal that seems to say "we reserve the right to fiddle about with these rates as we see fit".
[A bit like the ability to switch between the Retail Prices Index and the Consumer Prices Index - when we all know pensioners incomes are spent on goods that are going up faster than both of them].
Perhaps I need to put a cold towel round my head and read the total complexity of what is being obscured.

EST seemed to think these would be deemed figures, does anyone else have a better understanding of what the real unit of measurement for the generated energy is ?

I am not sure the advisor understood my point about the efficiency of a heat pump varying with the difference in the two temperatures it is being instructed to achieve (ie a lukewarm insulated floor slab, heated overnight, is much cheaper to run than bursts of hot radiators. This is a point lost on the occupants of social housing who "turn the bl**dy thing off so I don't have to pay for it when I'm out".)

The latter technique will likely turn on the big immersion heater and the occupant would have been better off sitting in front of granny's old three bar electric fire?

By the way has anyone got any feedback on the suggestion that the PV FiT figure for installations registered after March is being changed from the previously published "domestic" rates?

Martyn1981

John_Pierpoint wrote: »

By the way has anyone got any feedback on the suggestion that the PV FiT figure for installations registered after March is being changed from the previously published "domestic" rates?

Hiya John, not sure what you mean, have you heard/read something?

The current review system is to digress PV FIT rates each quarter, via a formula based on installs during the previous period.

I haven't found any info on the 1/2/13 review (assuming it will take place then), but with such low installs since 1/11/12 I'd suspect (please don't shout if I'm wrong) that any digression will be very small, if at all.

I think we're building up to a big cut soon however, as returns on install costs are now pretty high, and word is bound to spread, leading to another dash for the cash - which via install rates will naturally lead to a large digression.

One thing you have made me ponder, is if the 4.5p export rate will be increased, as wholesale costs appears to have gone up. I don't mean the annual inflation rise, I actually mean a change in the rate for new installs, like last year in August when it went from 3.2p to 4.5p, and the anticipated 16.5p FIT was reduced to 16p to counter balance.

So, if the export was changed to say 5p, would the new FIT be reduced (on top of digression) by say 0.25p? Pure unsupported speculation on my behalf.

Mart.

zeupater

John_Pierpoint wrote: »

.... EST seemed to think these would be deemed figures, does anyone else have a better understanding of what the real unit of measurement for the generated energy is ? ....

Hi

I'm pretty sure that the UOM would be kWh Thermal which, if metered, is established by metering the differential between the input & output temperatures as measured against the flow rate.

From what I've read on RHI related to domestic heatpumps (and this was some time ago !), it looks like deemed heat provision will be based on a BRE/SAP calculation for annual heating requirement for the specific property, this being supported by the exclusion of bivalent heating systems from the scheme in order to remove the possibility of claiming deemed RHI payments and continuing to provide heat from a cheaper fuel source ....

HTH
Z

John_Pierpoint

zeupater wrote: »

Hi

I'm pretty sure that the UOM would be kWh Thermal which, if metered, is established by metering the differential between the input & output temperatures COLOR=Red]and the electricity consumption?[/COLOR as measured against the flow rate.

From what I've read on RHI related to domestic heatpumps (and this was some time ago !), it looks like deemed heat provision will be based on a BRE/SAP calculation COLOR=Red]which is not something that can be created on a laptop in less than half an hour?[/COLOR for annual heating requirement for the specific property, this being supported by the exclusion of bivalent heating systems from the scheme in order to remove the possibility of claiming deemed RHI payments and continuing to provide heat from a cheaper fuel source ....

In theory there is no automated cheaper source of heat than a heat pump on Economy 7 rates, it is only when the pump cannot cope because of poor building thermal properties, or bad design or abnormally low external temperatures - only then will it exceed its capabilities and resort to burning full price electricity to make up the deficit of output from the pump?

HTH
Z

From those nice people called Daikin:

Bivalent heat pump


Using a special control system, an existing heating boiler can be operated in an energy-saving mode in addition to the heat pump. The boiler is then only switched into the circuit when the outside temperature is very low. The point at which this occurs depends largely on the heat demand and the heat insulation of the building and on the performance of the heat pump.

As a cost-saving auxiliary heating system, the air heat pump alone provides the heat for heating and domestic water in the summer 6 months and in the mild transition periods. In the winter the existing boiler installation provides heat for the house either additionally or exclusively.

John_Pierpoint

Martyn1981 wrote: »

Hiya John, not sure what you mean, have you heard/read something?

Mart.

I've heard nothing but "the cowboys" were trying to tell me that had inside knowledge.

zeupater

John_Pierpoint wrote: »

From those nice people called Daikin:

Bivalent heat pump


Using a special control system, an existing heating boiler can be operated in an energy-saving mode in addition to the heat pump. The boiler is then only switched into the circuit when the outside temperature is very low. The point at which this occurs depends largely on the heat demand and the heat insulation of the building and on the performance of the heat pump.

As a cost-saving auxiliary heating system, the air heat pump alone provides the heat for heating and domestic water in the summer 6 months and in the mild transition periods. In the winter the existing boiler installation provides heat for the house either additionally or exclusively.

Hi

I think that the issue around excluding bivalent systems is that there is a very good chance that a significant proportion of heating could be provided from alternative fuel sources.

I understand your point relating to the COP of heatpumps and the the use of E7 electricity, however, the BRE averaged seasonal performance which the RHI tariff is based will already reflect the poor performance in the very cold periods as well as the good performance in milder conditions ... it is also likely that a significant proportion of properties which would have heatpumps retrospectively installed will not have sufficient internal thermal mass to smooth temperatures to a level where comfort can be maintained with only providing heat within the E7 time-window. It is therefore extremely likely that homeowners with (gas & heatpump) bivalent systems would choose to use gas during the day in cold conditions and also to suppliment heat overnight in extreme-cold conditions, thus gaining a further financial advantage. Of course, there is a simple solution, but this would involve a requirement for every RHI installation to be provided complete with a calibrated thermal energy meter .... I'm pretty sure that I've read somewhere that the meters would cost somewhere well into the £hundreds for each installation and that's why they would only be required on larger systems.

HTH
Z

jamesingram

Cardew wrote: »

Do you not feel the EST would also be quite surprised to learn they were doing that kind of thing!!

sounds about right as you found out John.
Clearly the people who phoned you were lying re. EST
not cowboy ,but fraudsters, far to organised for cowboys.

I'm perplexed by this 'greendeal ' and even RHI
seems an enormous white elephant , figures just dont add up
though the 'Eco' side has some potential .

My first thought is it's designed to keep lots of DECC and other consultant people busy , using up most the available pot of cash before anything practicle gets done. The treasure can then declare it a waste of money and cut it
"We tried, as you requested, sorry it just doesn't work " said a regretful Mr Osbourne

Mananage it into chaos, so others can save the day and steal the glory.
X factor has learnt a few tricks from the politicial theatre
(or vise a versa ?) Just playing out a script.

rogerblack

zeupater wrote: »

it is also likely that a significant proportion of properties which would have heatpumps retrospectively installed will not have sufficient internal thermal mass to smooth temperatures to a level where comfort can be maintained with only providing heat within the E7 time-window.

Never mind that a three times more powerful heatpump is considerably more expensive, larger, maybe louder.

zeupater

rogerblack wrote: »

Never mind that a three times more powerful heatpump is considerably more expensive, larger, maybe louder.

....

... you've not come to the conclusion that the industry bamboozled the 'highly educated' wretches in the civil service yet again and skewed the consultation conclusions towards benefiting their own margins then ?? .... :D ... when will the public sector finally learn that there is wide chasm of difference between being educated and being intelligent ??

Z