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The domestic RHI needs 6-star installers. Who’s in it for the long term?

This is the key point: if you ask me, ensuring renewable heating systems work well is down to the quality of the installation – and that means it’s up to you installers!

Following the EST heat pump field trial, a lot of work was done on the MCS installer standard, MIS 3005.  With it, I think the domestic renewable heating industry is ready for the RHI. MIS 3005 is now a pretty robust standard; it requires detailed measurements and calculations and forces careful consideration of the most important elements of a new installation.  But it’s also there to help you – the ground-loop look-up tables for GSHPs, for instance, make sizing a domestic ground loop straightforward.  All MCS standards must be followed in the domestic RHI and we’re working with MCS, who are beefing up their surveillance, to make sure they are.

For heat pumps, the domestic RHI is designed in a way that pays more to installations designed to be more efficient.  That’s on top of the extra fuel bill savings customers will benefit from.  We have done this by basing RHI payments on kWhs of renewable heat using the Temperature Star Rating in the Heat Emitter Guide. There’s an example of how this will work in chapter 3 of the policy document.

We’ve introduced this measure because we want installers to have both eyes on (a) reducing heat losses (which increases the Temperature Star Rating and reduce customers’ fuel bills); and (b) designing an emitter system that can run at low temperatures (which also increases the Temperature Star Rating).  We expect installers to target properties that are already well insulated because of this, since these installations will find it easier to get to 4, 5, or 6 stars.  Do check your calculations thoroughly because this is an area where we anticipate Ofgem will have a thorough audit regime, in addition to the surveillance already inside MCS.

Designing the most efficient system possible is important but I think it’s even more important to check your own work so that actual performance matches design performance in every case.  That’s why RHI payments will be increased by £200/year – £230/year for any customer that buys a Metering and Monitoring Service Package.  Have a look at our guidance document on what this involves and who’s eligible.  For the customer, a Metering and Monitoring Service Package provides peace of mind that their installation is working well – subsidised by the Government. 

For the installer, this is a golden opportunity to review real-life data from the installations you do and learn from it.  For instance, you can confirm flow rates, flow temperatures, cycle times and supplementary or immersion heater use.  (When I review data from RHPP installations, I can’t tell you how often I see heat pumps turning ON/OFF every few minutes – it’s bad for efficiency and wears components, so please don’t let it happen!!) 

As a manufacturer, reviewing this data with your installers is a great way to support and build the reputation of your supply chain.  For Government, we can aggregate the data and make sure everyone has the opportunity to learn from the most common pitfalls.  I think they’re a great opportunity to make sure your current and future customers get a genuine 6-star service, so if the equipment you install is eligible, I hope you consider designing this equipment into your installations straight away.

Here’s a final thought: if you’ve read DECC’s recently-published heat strategy, or played with DECC’s brilliant – and now international – 2050 calculator, you’ll see that this Government is committed to domestic renewable and low-carbon heating for the long term.   So the future is bright.  How bright, if you ask me, depends on you, the people in industry.  Do you have the aspiration to offer a 6-star service?  To go and check for yourselves and your customers (using metering) that all of your installations are functioning as well as they can?  To hunt out continuous improvement?  Invest in training and skills?  And drive down costs?  At DECC, we hope so.  The domestic RHI is there to work hand-in-hand with industry to make these things happen.

43 Responses to “The domestic RHI needs 6-star installers. Who’s in it for the long term?”

  1. Paul Dodgshun says:

    At the head of the blog is a statement by Chris Wickins
    ‘This is the key point: if you ask me, ensuring renewable heating systems work well is down to the quality of the installation – and that means it’s up to you installers!’

    The other key point, which can easily dominate, is the Carnot Efficiency of the pump. The Carnot Efficiency is controlled by two numbers, the inlet and outlet temperatures of the pump. These are the maximum theoretical values for 5/30C, 5/55C and 5/60C:-
    This caculation comes from Carnot’s Law (’s_theorem_(thermodynamics)

    The 5/30 at 12.12 represents the best air-to-air heat pump (aka an air conditioner). The 5/60 at 6.05 represents the high temperature air-to-water retrofit heat pump (as pushed by the draft domestic RHI). The 5/55 at 6.56 represents the ‘After the “sping 2014″ launch you will not be able to get D-RHI for any high temperature application requiring flow > 55°C’.

    These efficiencies turn into electricity bills. The pumps at 5/60 therefore cost twice as much to run as the pumps at 5/30. The improvement supplied by 5/55, as compared to 5/60 is 0.51 (about 10%). Just another 90% to go to catch up with an air conditioner.

    It costs half as much to run an air conditioner at 5/30 as it does to run a high temperature air-to-water retrofit at 5/60, for the same heat production. If installers have to offer ‘best value’ in accordance with consumer mis-selling legislation, then how do they justify selling a pump at 5/55, let alone a pump at 5/60, as compared to a pump at 5/30?

    • Bojun says:


      In the Carnot Law, it’s right. However in reality, the HP has much more efficiency losses during the circulation and pressing. So you need to divide the COP by half in the real world. It’s right an Air-Con system looks like a more efficient way of doing the heating, however, RHI doesn’t support Air-Air system, you have to have some system that can do the DHW as well. Besides, I don’t think Air-Con unit works that efficient as the colder it gets, the warmer you want in your room, vice versa…So the COP will drop dramatically if you consider it’s 0C outside and you need 35C in your house plus you need something extra to heat your DHW.
      If you only need to warm one room up and you have main heating system and hot water from a gas boiler, I would recommend you to have a small Air-Con in one of the rooms that doesn’t have heating. Would be nice. Hope that helps.

  2. trudi wheat says:

    Just having spent 3 years chasing my tail over Green issues I feel well and truly let down by the Green deal/MCS/local council.Very briefly as part of a change of use condition we had to find 10% renewable energy We had SAP documents produced on” as is” and” will be” for the Kwh consumption (63000kwh) which bore no recognition to energy bills(much lower) of our Victorian town house. 6.3 kWh needed to be found. Our appeal on the 10% was refused so the only way to get 10% was an ASHP.(Solar impossible)
    According to the SAP we were E E for Co2,if we didn’t improve the house but just use the ASHP we were E E but only 1 point away (as far as I can make out from a D onCO2)
    Having installed ASHP,draught proofed sash windows, insulation etc in excess of10K
    Green deal gives us F and F HELP get my sanity back please.

    • Bojun says:


      The flaw in RdSAP is even you are having a ‘GREENER’ heat pump put in as a renewable, it won’t count it as renewable in the software because it uses ‘ELECTRICITY’. So I would say, forget about the SAP rating, it’s useless to HPs, they are only gas friendly!

  3. J S Harris says:

    We’re building a new passive house, that has a worst case (-10 deg C outside temperature) heating requirement (ignoring passive gains from occupants and appliances) of just 1.6 kW.

    I’ve just been asked some questions by our MCS accredited supplier re: the U values of wall, roof, floor, walls, doors, windows etc, plus their dimensions. No problem, I gave them to him and suggested he’s also need the permeability and heat recovery ventilation data. “No”, he says, “the official software assumes ventilation rates room by room without heat recovery ventilation”.

    The result is that the “official” RHI software is going to massively (as in around 400 to 600%) over-estimate our heating requirement.

    Is this barking mad or what? It looks like if we want to claim RHI we’ll end up with a massively over-sized heating installation, that will then run on average at maybe 5 to 10% of it’s capacity, which will be ludicrous innefficient.

    I thought RHI was intended to promote efficient heating systems, it seems I was mistaken. Why on earth doesn’t the RHI system accept something like SAP, which, despite some failings, does at least allow for MVHR and reasonably accurate heat loss rates.

  4. Chris,

    There is lots of good debate on this site with many very respected views on matters that appear to be working and those that are clearly not.

    I have grave concerns over the use of deemed annual energy consumption figures and having experienced RdSAP in action, I just can’t believe some of the figures both this and the Green Deal OA actual churn-out.

    Two things spring to mind at this stage:-

    1) Has anyone at DECC or the EST actually produced an illustration on how the RHI payments will be calculated in reality? This would help us to at least understand which inherent metrics or variables have an effect of the final RHI payments to the customers.

    2) Has DECC seriously considered the RdSAP impact on the 20/20 targets for the UK reduction in carbon emissions through the take-up of Renewables? Surely, if the annual consumption / RHI figures are suppressed, then so must the carbon saving too!

    Carbon target alarm bells ringing loudly!!

    Thoughts welcome, thanks.

  5. Iain Thomas says:

    We have done some retrospective research on MCS calculations we have carried out using the room by room calculator. We have noticed a MAJOR issue:

    On an example MCS Certificate, it shows an Estimated Annual Generation of 16,707 kWh. This is taken from the Heat Loss Design Table, where it’s calculated as the sum of:
    1. Space Heat Consumption = 12,341 kWh
    2. HW Consumption HP = 4,366 kWh

    We understand that the 4,366 kWh for DHW is calculated:
    ( 3 + 1 ) x 1 x 45 x ( 55 – 5 – 10 ) x 4187 / 3600000 / 70% x 365

    What we can’t understand is how the Space Heating Consumption is calculated. In the DHDG spreadsheet downloaded again from the MCS website to get the current version as of 27 September 2013, this seems to be hard-coded as 12,341 kWh for all installations! That doesn’t seem right. Surely the Space Heating Consumption is calculated from the design heat loss, using factors such as the degree days, floor area, wall areas, U values, etc.

    Can you explain why the 12,341 kWh is hard-coded in the spreadsheet?

    The ramifications of this are plain and clear – RHI could be incorrectly calculated and ALL MCS installers using the approved DECC sheet could end up having to issue all new MCS certificates – who is going to cover the cost for this?

    I wonder if anyone else has discovered this?

  6. John Martin says:

    The field trials were a great piece of work and certainly an eye opener, installers must undertake appropriate designs, install correctly and commission the appliance with care, ensuring also the customer is very clear on how to use the system to its maximum efficiency as correct use of the system usually means a change to lifestyle, but has a major effect on the operational efficiency of the system.
    A question I have is that metering of the system makes absolute sense and many will take up this option, there must however be a “cap” to the amount of metered installations which can be completed and claiming the additional payment incentive, is there a target number?

  7. Gordon Lacey says:

    I am a potential buyer of of ASHP but am very confused, along with the four potential installers (all mcs) who have visited the property. It appears impossible for installers to give me RHI payment predictions although they all come within 10% of each other on the heat loss figure. One installer is particularly keen on a high temperature HP, and so am I, as it less disruptive in terms of radiator and water cylinder change. Others say that such a system will not be eligible for the RHI payments from April 2014.
    I am willing to pay for a system but not unless I can have confidence in the predicted running costs and RHI payments. I cannot be alone in delaying implementation until, if ever, I get clarity. Bad for the industry, bad for Green Deal take up and bad for reducing CO2.
    When will this picture be clarified to encourage widespread adoption of the technology ?
    An early reply would be appreciated.

    • Reading the papers from DECC you could assume to see your legacy installation agreed to be >/= 2.5; Your problem is, that you will end up with an SPF of 1.5 or even lower and thus the heating system will be more expesive than any fossile system installed/planned. The D-RHI payment is by far not enough to make this work!
      Watch out to get a proper heat pump delivering a SPF of > 3 thus your installation/payback will work. It is not just about emitters it’s also about heat pumps used. After the “sping 2014″ launch you will not be able to get D-RHI for any high temperature application requiring flow > 55°C.

      • Gordon Lacey says:

        Is it fact that >55 deg systems won’t attract RHI ? Surely if they can achieve an SPF of >3 then they will be eligible ?
        I , as a consumer, look as though I’m being forced into a significant amount of radiator changes to allow a low temp a system to be used which may only have an SPF of 0.5 better than a good high temp system.

  8. g bell says:

    For GSHP and domestic RHI. Can you acheived 100% of the RHI payments if your SPF is 4.1. I am being advised that for any system >4 the “1-spf calc” doesnt apply ? Is this correct the DECC policy document doesnt mention this concession?

  9. Simon Lomax says:

    Householders considering the RHI will want the best possible financial return. In part, this could be achieved by selecting an installer who is most prepared to bend the rules. It is clear that the EPC process is malleable and pretty easy to see how the heat demand figure can be inflated. Indeed, DECC has accepted the variance could be +/- 20% and that has a significant impact on tariff payments. Worse, further benefit accrues if a rogue installer chooses to self-certificate any installation with a generous ‘star rating’. Their offer will be very appealing to the householder.

    Folks who are tempted to behave in this way are unlikely to be the ‘six star’ installers that Chris is so keen to embrace. Instead, they will be opportunists attracted into the market by the lure of public subsidy and the lax regulatory regime. They have been given a charter to prosper. All might be okay if there was any meaningful enforcement but the MCS certification bodies are hardly noted for their ability to spot errors yet alone impose sanctions on the guilty. And anybody thrown off MCS could rejoin the next day!

    It would be a real shame if the market was hijacked by rogue installers. In some cases, they could be merely ignorant; in others cases, they could be a deliberate intent to take advantage of inadequate policy. Somewhat sweetly, DECC assumes that all installers will play nicely. Sadly, experience gained in the solar PV market suggests this isn’t likely to be the case.

    But it gets worse. Honest installers could possibly get themselves into trouble.

    Imagine a scenario whereby a bungalow owner advises that they will be laying ceramic tiles on a screeded ground floor; ideal condition for UFH so the heat pump installer could legitimately claim a low flow temperature and a ‘six star’ rating. Bingo, a high RHI payout, everybody is happy, trebles all round. But the next day, the householder has a change of mind and chooses to lay a heavy carpet. Suddenly, in order to heat the rooms, the flow temperature requirement jumps up 15C and the ‘star’ rating plunges. What happens?

    If DECC claims a random audit will take place to protect against abuse, who will be guilty? The installer who didn’t realise the homeowner had changed a floor covering or the homeowner? It can only be the home-owner. Maybe they deserve to be stripped of their RHI entitlement. But what if the change in floor covering was prompted by a new owner acquiring the bungalow? Would they know any better? And does Ofgem require notification every time a floor covering changes and does somebody need to determine the impact on flow tempetature and update the rating?

    This is possibly an extreme example but there are all sorts of ways to distort the real efficiency of any installation. Those with the greatest appetite to explore those possibilities will prosper. And they will not be ‘six star’ installers. I hope I am wrong: in reality, I have far more experience of this market than anybody at DECC so I fear I am right.

    The solution, of course, is the use of Look-up Tables to eliminate any ‘gaming’ around the deemed heat demand figure and a fixed tariff regardless of perceived efficiency. Running cost savings should be enough to encourage more efficient designs. Installer success should be based upon an ability to deliver an installation that performs as projected rather than a willingness to exaggerate or cheat.

    Amd policy should support this ambition.

    • Jacob Johnson says:

      I agree with all of what Simon Lomax has stated, particularly the last comment relating to rewarding installations that actually perform to predicted running costs. This will encourage best practice installations and new ‘UK’ manufacturers into the market (if they know their product development and efficiency will be rewarded)

      If DECC leave things as they are I am not particularly looking forward to becoming a dirty salesman (I am currently honest and open to customers, selling the benefits of running cost savings and our installation expertise), but every installer will abuse the system, so I guess I will have to join the club. At the end of the day I am here to earn a living and sell, not really my problem if the people who write the policy have very little common sense or empathy. Only kidding of course I will follow DECC’s back of fag packet rules!

      Are any of the 20 or so ‘bloggers’ going to get involved? Or are they all busy working…or re-writing a bullet proof policy!

  10. Jacob Johnson says:

    Is this blog still live/monitored??

    Not had a response from my previous question to DECC, submitted:
    August 15, 2013 at 1:02 pm

    Do we just install high temperature air source heat pump systems, in the hope that DECC will eventually provide final details that they can/can’t receive RHI payments?

    Bit of a risk for the consumer, if they are paying £15k plus for a system…some clarification on this subject would be much appreciated.

  11. Jacob Johnson says:

    Chris, I have just read one of your comments from the DECC webchat:

    “You are correct that new ASHP systems with a design emitter flow temperature of 55oC won’t be eligible for the scheme. The minimum Temperature Star Rating for ASHPs is 3 stars.”

    Does this completely rule out high temperature ground and air source systems? Therefore in practice you are asking every property owner with standard radiators to replace them with UFH or fan convector radiators, is this correct?

    • Chris Wickins says:

      Jacob, sorry for being slow to reply to you. I hadn’t looked at this for a while.

      High-termperature systems are not ruled out from the RHI. However, all ‘new’ (i.e. installed after the scheme opens in Spring 2014) heat pump installations need to achieve an SPF>2.5 judged using the Heat Emitter Guide. In the Heat Emitter Guide, GSHP at all flow temperatures result in an SPF > 2.5 but this isn’t the case for ASHPs with higher design emitter temperatures.

      Legacy systems (i.e. systems registered on the MCS database before the RHI opens for payments) will get a default SPF of 2.5 regardless of the design emitter flow temperautre because a lot pre-date the Heat Emitter Guide. Or alternatively, they can assessed according to the latest version of the MCS installation standard, which may result in a higher SPF being assigned.

      I hope that helps. CW

      • Jacob Johnson says:

        Chris, thanks for your response.

        I have many issues with DECC’s policy for the domestic RHI, I have outlined several in this blog and my comments below. I feel that DECC have failed to engage properly with installers and the renewable heat industry. You have made/are making decisions without applying empathy, eg putting yourself in a position to actually sell, design and install this equipment. Here are a few more of my issues, I will keep them coming:

        How will the star rating selection process be monitored? At present it is open to discretion. The green deal is the same, people are stating that their walls are not insulated when actually they are, just to bring up their kWh usage. People will do the same with the SPF.

        I had a green deal assessment completed a few weeks back. It came out 40% less than the MCS method. A large room in the property has over 50% of wall space glazed. The assessor felt this was not excessive in his calculations (I assume he ticks a box for this and then the software makes a few more assumptions!). I asked him to change the calculation to excessive glazing, but the kWh usage actually came down!! Try explaining this to a customer who is considering 2no. ashp units to run an 18.5kW heat load. There are also only 2 u-value options for cavity wall construction, something like before and after 1989, another area lacking detail and open to discretion.

        The RHI payments cover only half of the install costs of ashp systems (well installed and specified systems), the rate is far too low. Everyone will install pellet boilers, the price of pellets will skyrocket. The UK is an ireland and does not have the biomass capacity to fuel large pellet requirements. We are already importing from Canada (Drax), Sweden (pellet supplier who states their pellets are UK manufactured) and other parts of Europe. The European market for pellet supply is already saturated. The pellet manufacturing market in the UK is not sustainable, try speaking to people in the industry, they are already pulling out as there is no money in it, to manufacture or deliver the pellets. Bagged pellets offer a saving of less than 15% against oil, its pathetic. ASHP’s are the solution for the domestic market (where gshp’s are not suitable), however DECC have failed to recognise this by applying a low tariff level, due to poor quality ashp installations, that have ruined the market for competent installers. It will all end in tears when people install pellet boilers and they are not making any fuel savings. What is DECC’s long term strategy? Do you want to encourage biomass more than heat pumps?

        • Steve Irving says:

          How is the electricity produced using ASHP’s is a point in question, burning fossil fuel? At least biomass is “young” carbon that is easily replenished.

          • Jacob Johnson says:

            I agree that biomass can be replenished, but most commercial RHI installations are biomass, most domestic installations will go down this route, due to 12.2p payments, compared to 7.3p for ashps. Where is all the fuel going to come from? If the government build some nuclear this will significantly reduce carbon emissions associated with grid electricity for heat pumps.

        • Biomass boilers in particular wood pellet boilers are very economical to install and do deliver sizable energy savings compared with an oil fired appliance. Wood pellet fuel is around 30% cheaper that heating grade oil and if designed and installed correctly they knock spots of an oil fired boiler. We know this for a fact as we have fitted many of them and all have reported reduced fuel consumption after year 1 compared with oil. This is mainly down a correctly sized appliance and the right accumulator tank. Air to water heat pumps have there place in the market but in our experience they are better suited to a new build property with a low heat loss and a low temperature emitter design. All the norm with a new build. If we installed Air source units everywhere across the country where would we generate the electricity to power them from? Biomass is really the only stand alone technology and has been awarded the highest domestic RHI incentive. It is also a technology that consumers understand and is very robust in it operation. Something that can not be said of heat pumps. I would point out that we are both MCS registered for Biomass and Air Source so we have installed and tested both systems. Biomass is the future for the majority anyway.

  12. Darren Stockall says:

    Tony, Steve and Lewis. We at Worcester Renewable Energy would agree with you. Making RHI payments against the heating energy consumption over a year in kWh for spacing heating and domestic hot water from an EPC based on reduced data SAP, not even full SAP, is not as accurate as calculating the requirement using full heat loss calculations based on actual U-values, EN ISO 13790, CIBSE Guide A and BS EN 12831 as required under MCS 3005 3.1a Clause 4.3.12 c).

    This does indeed also seem to greatly contradict the statement in MCS 3005 3005 3.1 page 21:

    “Notes on determining the total heating energy consumption
    The Standard Assessment Procedure for dwellings in not recognised to accurately determine the heating and domestic hot water energy requirements of real dwellings”

    We foresee the differing heating energy consumption figures presented to the client on the EPC and by the Installer as required under MCS causing confusion and dissatisfaction as the figure on the EPC will inevitably be significantly lower than the MCS figure and because RHI payments are to be made against the deemed EPC figure, customers will undoubtedly query the figures and potential loss of income.

    An example of this is borne out by one of our recent projects where the total heating and energy consumption for space heating and domestic hot water from the EPC is 21,640kWh (18,246 heating/3394 hot water) compared to 33,834kWh (30,227kWh heating/3607 hot water) from MCS calculations which translates to a 12,194 x (1-1/3.6) x 7.3p = £642.89 loss of RHI income/year for the 6* Installation.

    This difference between estimates and associated issues surrounding income could be eliminated if a metering and monitoring service package was installed and RHI payments made against this as is the case with second homes and bivalent systems but as payments under this method are still capped at the deemed figure this will only cause further issue if the actual metered energy use exceeds that estimated.

    • Chris Wickins says:

      There are a few comments about differences between the ENERGY consumption figures on the EPC and those calculated using the spreadsheet provided with MIS 3005 so I’ll try and address them.

      We have done quite a bit of analysis inside DECC on the MCS spreadsheet ENERGY calculation. (We think the first part of the spreadsheet used to determine POWER is brilliant by the way.) The final column of that spreadsheet – the ENERGY one – uses the heat loss coefficient (in W/K) and degree days (in K.days) with a (default) base temperature to estimate annual energy consumption (in kWh/year). It’s our assessment that the assumption of a 15.5oC base temperature (which is the default in the MCS calculation) could be too high, especially if the building is highly insulated and consequently the adventitious heat gains from water heating, cooking, lighting, appliances, solar and metabolic sources provide a large fraction of the heat demand at any given time. This could mean that the MCS calculation is overestimating compared with an EPC, which is what people are reporting in this blog, through the webchat and in other correspondence. From CIBSE guide A, if the base temperature in Birmingham is 14oC rather than 15.5oC, the number of degree days decreases by 19%.

      With regard to the notes on page 21 of MIS 3005, I have to admit to being involved in drafting those. They aren’t very balanced and I have therefore been trying to get them replaced with something more factual for a while now. It remains true that SAP doesn’t vary energy consumption according to location or occupancy and occupant behaviour (NB: RdSAP does now vary energy consumption according to location). However, SAP and RdSAP do make a thorough estimate of adventitious heat gains from water heating, cooking, lighting and the other things I mentioned earlier, which are very important when determining annual space heating energy consumption. The spreadsheet provided with MCS doesn’t do this – all those factors have to be wrapped up in the base temperature assumption.

      Remember that MIS 3005 only requires the installer to “assess the annual heat load for the building (space heating or hot water) using any suitable performance calculation method” in clause 4.3.1 a). RdSAP is one of those so you don’t have to use the spreadsheet determine the annual space heating ENERGY demand if you think it will be confusing for customers. You must still assess the space heating POWER required on the design day, which the spreadsheet does in accordance with BS EN 12831, though.

      Here’s another source to look at… Have you seen the comparison of [Rd]SAP with measured heat use from the EST field trail phase 2? The agreement between RdSAP and measured data on page 122 of this report looks OK to me:

      It’s not the biggest data set but it does provide some confidence that RdSAP is appropriate to be using.

      Estimating annual space heating energy consumption is difficult and there’s an active academic community debating it. It would be great to have more evidence to look into this further so if anyone is able to share full RdSAP and MCS spreadsheet calculations (with all of the accompanying inputs) then please send them to

  13. Jacob Johnson says:

    The Green Deal is a shambles and a scam (7% interest and the finance is still not available 1 year on!!!). What a huge mistake by DECC including this with the domestic RHI, do you have any common sense? Sometimes you have to acknowledge when something has failed, move on and create an improved solution. The Green Deal EPC is like computer code to the untrained eye (in fact the green deal assessor we use does not understand the figures) and does not make any sense. The potential savings in £ do not stack up and are often more than people are already paying for their existing heating bills, how is this possible?

    What a joke, who designed the Green Deal? This person(s) needs an injection of common sense, good installers have plenty of this and can explain figures and systems to the customer (why don’t you leave all the responsibility with the installer???). The Government has backed the big boy companies, so that they can try and make a few quid out the Green Deal, and they have failed to engage with smaller companies, the scheme is a scam.

    The green deal assessor that we are using has just phoned me to say that he is now not doing assessments. He has to spend 6 to 10 hours completing a survey, trying to explain figures that do not stack up (and that he does not understand) and he is then bombarded by emails, because the customer does not understand the assessment. Well done DECC! Don’t ruin the domestic RHI, you have worked hard to get it to this point, we don’t want another green deal failure.

    The green deal EPC needs to be scrapped and the MCS room by room heat loss method should be used in its place. The MCS method provides room by room data in kW (heat load) and kWh (heat usage), which any customer can understand. When improvements are made this reduces the kW and kWh, making it simple to calculate running cost savings and explain this data to the customer.

    Stop messing installers around, you say you want to build a new renewable heating industry, your domestic RHI policy is anti business and anti customer, sort it out! I would be happy to meet with DECC to demonstrate a plan that includes lots of common sense and a system that will work.

    Yes we want to be a 6-star installer and already follow the MCS standard. Its a shame we don’t have a 6-star government department.

  14. Tony says:

    Steve, this is something most installers cannot understand, After the energy Saving Trust did a survey a few years ago and found heat pumps were not performing and many were undersized, DECC specified that an MCS installer were not permitted to use the SAPS calculation when determining the heat loss or heating requirements for a property as it was too inaccurate and not fit for this purpose. Now for some reason they deem it suitable to calculate the grant which on a Ground Source unit can be over £100,000.00 (yes the number of zero’s is correct) of tax payers money. The only reason I can think of is that SAPS underestimates the heating requirements of a property, therefor the grant will be lower. Call me a sinic but it may also be a way of boosting the Green Deal Statistics!

  15. Steve Jackson says:

    I am in the process of having an ASHP installed with the intention of claiming the RHI payments so I had a Green Deal assessment done. This showed the total space heating requirement is 20,577kWh on a floor area of 268 sq m. The MIS 3005 calculation shows a space heating requirement of 34,932kWh on a floor space of 243 sq m. I am confused by the very substantial difference in these figures and concerned since the RHI payments will be based in the EPC figure which is significantly lower than out typical annual consumption.

    • Just had a Green Deal assessment carried out for one of our customers who we are installing an air source heat pump system to replace his 15 year old oil boiler. The GDAR estimates it will cost him £21 more a year to heat his property with ashp as opposed to oil. We have installed over 400 heat pumps and we know this simply isn’t the case. The default data being used in EPCs and GDARs is incorrect and could make me look stupid when I quote the savings that can be made which after 7 years experience in installing, sizing of heat pump systems from 5-160kw know to be true.
      As mentioned by Steve Jackson above the EPC also shows much lower estimated annual space heating requiremnts than what is produced by MIS3005 which is surely a better indicator, when based on location, altitude and heat demand of buildings.
      I understand the reason for bringing in independent assessors but for us who have been designing heating systems successfully and estimating usage and savings very accurately for years it is more than a bit annoying to see what some of these reports are spitting out.
      Hardly any of our heat pump systems have running times of less than 2000 hours a year yet EPC typical run times seem to be more like 1500hrs (probably brought about by the fact boilers are used frugally, maybe 6-8 hours a day for six months). I then look like I am incapable or even deceitful with the figures that I am using when this simply isn’t the case.
      The RHI is designed to increase uptake of renewables but if you were to look at some of these reports you would think otherwise.
      The guideline prices are also simply wrong: £9-14K for a 2.5kwp solar pv system – nobody in the market would do this for over £5-6K.
      Until these reports reflect accurate estimated annual usage and savings, I feel the consumer is going to become more and more confused and it will only damage an already fragile market.
      Any thoughts anybody?

  16. Lee Rolison says:

    I’m glad to see that there are plans for ‘beefing up’ surveillance. It’s not often an industry looks for greater regulations, but in the case of ensuring that installations are up to a high standard in a technical industry; I think it’s essential.

  17. Darren Stockall says:

    Good blog Chris, we at Worcester Renewable Energy agree with your comments.

    That said we do not understand the rationale behind DECC’s decision making process to make Domestic RHI payments for heat pumps and biomass boilers against a deemed estimated annual heat usage from a EPC rather than that deemed by the MCS installer, as is the proposal for Solar Thermal.

    Under MCS requirements MCS installers already accurately calculate the FLEQ run hours from the results of full room by room heat loss calculations in accordance with BS EN 12831/CIBSE.

    DECC and MIS previously moved away from SAP stating that is was not accurate enough for heat pump sizing and running calculations due to its generic nature based on a notional building rather than the actual building in question where the heat pump/biomass boiler are to be installed.

    To now propose to make RHI payments on it is surely a backward step.

  18. Malcolm Lowther says:

    There is no mention of biomass systems that are above the 45Kw MCS upper limit, it was said that these systems would be allowed if they were metered,
    I have a number of these systems awaiting some news, there are many households that easily come above 45Kw

    • Lucy Longstaff (DECC) says:

      Hi Malcolm

      Thanks for the comment – I work on the policy alongside Chris. Any systems that are above the MCS upper limit will not be eligible, as all systems must be MCS certified and installed by an MCS installer. This is the same as our position in the consultation. From our perspective, the consumer protection and quality assurance provided by MCS is critical to the success of the scheme. If the MCS limit was extended then these systems could be eligible in the future. One last point – if a biomass system of 45kW or less is installed alongside another renewable system or a back-up boiler, this would be eligible but the biomass would need to be metered.

      • Andrew Tolfts says:

        Not being able to install >45kW biomass systems and claim d-RHI is a glaring error which should have been corrected after the comments received during consultation. There are many larger homes, typically solid wall properties off the gas grid which cuold be served very well by a single biomass boiler. To suggest that more than one heating system should be insyalled to reeduce the biomass size is to heap extra cost and complexity onto customers. What is Decc going to do to rectify this situation?

      • Hi Lucy,
        Further to Andrew’s question dated 15th August the 45KW. Legacy installations were not considered.

        I have now got to go back to see several customers who have had two or three seasons of heating using biomass boilers over 45Kw in size and explain to them that in order to get any RHI payment I shall have to remove their properly sized and efficient system and replace it with an undersized biomass boiler with a further back up system and heat meters in order to qualify for the domestic RHI. Due to costs and space restrictions this will in most cases have to be an oil fired “assist” boiler. So I am therefore having to scrap a perfectly good biomass boiler that is covering 100% of their annual heating load and replace it with an undersized one that will only cover a percentage of their annual load with the balance covered by burning oil. How does this fit with your concern for consumer protection and quality assurance, and carbon emmission reduction?

        I also take issue with your comment that “This is the same as our position in the consultation”. If you are implying that your policy has been consistant on this matter since July 2009 it has not. If you look back at the consultation in Feb 2010 you state “Work is now underway to extend the upper limit of MCS by the end of 2010. For
        biomass the limit has already been extended to 300kW, and other technologies are
        similarly under consideration. We anticipate that for all renewable heat technologies up
        to the upper limit, the RHI will require that beneficiaries use only MCS-certified (or
        equivalent) installers and equipment.”

        It is madness to have a policy that excludes the largest domestic heat users from the RHI incentive. These are the properties that biomass works well for and their conversion will save the most carbon.

        I believe your original policy draft was correct, i.e. that installations up to 45 KW should be be fully MCS accredited and over this limit the boilers should comply with emissions targets, and therefore efficiency targets, and the installation should comply with all aspects of the MCS installation standard.

  19. Having been in the industry some years now and having first hand experience of rectifying poor designs installations that were done purely to get a sale with no mind to efficiency or product longevity, I am thrilled to see that we may finally achieve a level playing field, MIS does this to a degree, however designer training and registration under an approved body has to be the next step, and enforcement therein!

  20. Robert Meeks says:

    Its a positive time for the industry and it looks as though everything is in place now for a successful scheme.

    I would point out that the increase in annual RHI from a 5* to a 6* system is very small (~1.5% increase) and would not cover any additional investment in distribution but I applaud the aim of the legislation.

  21. Phil Hurley says:

    Good Blog Chris and we at NIBE agree with all your points!
    Installers are the key to the success of RHI and development of renewables in the HEAT Strategy. Installers are the first point of contact for most potential homeowners so have to the correct information and training.

  22. Chris Davis says:

    Good summary Chris, feedback from the market now the euphoria/relief has faded is that many reputable installers are thusfar a tad confused about the (very sensible) approach to paying only on renewable heat, so there is a job for MCS to do here on making sure this is well communicated.

    6 Star installers? Fully in agreement with your sentiment BUT we MUST now address the serious training deficencies in our industry. The quality of training on the design of heat pump systems is frankly shocking and needs to be addressed urgently if we want to deliver on the sentiment of MIS3005 and good intentions of the domestic RHI (which I applaud and am pleased that the fuel cost savings from a quality install are a big part of the payback figures).

    I think you know my views on the mercenary approach the main training bodies are taking towards heat pump installer training and nothing seems to be improving. There is STILL no accredited training that covers the scope of MIS3005 – so if we are to grow this market, where are installers going to get educated on what they need to do (and why).

  23. Tony says:

    The idea for encouraging energy efficiency is great but unfortunately the difference in payment from a poor system to the best performing system does not nearly reflect the difference in cost of installation. With a SPF of 2.5 the grant (7,3p and 18.8p) is reduced by 40% and with an SPF of 4.3 (the highest level achievable in the heat emitter guide) the grant is reduced by 24%, reflecting a difference of only 16%. The difference between installing a very basic radiator system running at 60 Deg C on a ground source system with an SPF of 2.8 (or probably just leaving the existing radiator system in a retrofit and costing nothing) or installing an underfloor system running at a flow temperature of 35 Deg C with an SPF of 4.3 is a lot more than 16% of the grant funding. The idea is good but the current emitter guide is just that, a very rough guide. With correct design, construction and equipment like whole house heat recovery units, SPF’s of much higher than 4.2 are achievable but do not seam to be recognized.

    • Lucy Longstaff (DECC) says:

      Hi Tony

      Thanks for the comment. I work on the policy with Chris. We did quite a lot of analysis on this issue, looking at the costs of upgrading systems to higher design SPFs (in terms of the emitters and also the ground loops for GSHPs) and the relationship between rate of return and SPF. We found that up to a point, the combination of higher RHI payments and increased fuel bill savings resulted in increasing rate of return with SPF for both ASHPs and GSHPs. The fuel bill savings were a very important part of the overall rate of return, so it’s important not to just consider the RHI payments in isolation. We agree that the Heat Emitter Guide is only an estimate, and may not match reality – in the future, we’d like to move to metering of all installations, but at the moment we don’t think the industry is ready for that. In terms of heat pumps achieving an SPF of much higher than 4.2 – none of the heat pumps in the EST Field Trial Phase 1 achieved close to that level, and while more recent results from RHPP are showing a small improvement in performance, we think there’s a way to go yet before we see heat pumps routinely achieving SPFs outside the HEG boundary.

  24. Cliff Arnold says:

    A rousing call to arms Chris! I fully agree that MCS accredited installers need to enter this industry with nothing more than excellence as a top priority. If acheiving the highest standards is not in your remit then please think again about renewable heat.

  25. Brian Cox says:

    There is a good case for using hybrid systems in order to maintain the best efficiency. EG air source heat pump with condensing boiler switching at the bivalence point

    So far I did not come across this in the documents.

  26. The standard MIS 3005, the robust approach MCS take and the high quality of MCS Installers, means the Renewable Heat Industry has the foundations to ensure the RHI is a resounding success.

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