ASHP, SUNAMP, UFH, PV Panels

[Coops85]

Hi,

 

i am just trying to get to get my head around the renewable sources that have been planned on our build. 

 

So am I right in thinking that the PV panels power the ASHP which heats the underfloor heating and the SUNAMP powerd by PV can be used for DHW? 

 

We have quite a large large area of PV panels planned as that has been stipulated by the council.  We have had to book in 3 phase electrical supply to the site. 

 

It is to be a  5 bed house with 2 adults and 4 children hoping to live in it.  Does the amount of people using it make a difference on the size/type of ASHP or size/type of SUNAMP? 

 

Sorry about what maybe very obvious questions. I really want to have a good understanding of the Renewable gadgets before we start installing/using them. 

[PeterW]

No.1.... none of the things you mention are renewable gadgets..!!! They are the core to getting your heating and DHW right..!!

 

You need to work from basic principles - for example what is the expected heat loss from the building, then you can work out what you need for heat provision through the ASHP. 

 

Secondly, how many bathrooms / baths / showers are you planning as that will determine the number of sunamp units you will need. 

 

With you saying you have a large amount of PV and are planning 3 phase, it sounds like you are planning to grid tie the lot..??

 

It’s not necessary and only really if you want the FIT as you could run an isolated thermal store as a buffer and then use it to dump from a section of your PV panels. There are also grid restricted inverters that limit your export below the threshold needed for a larger supply. I think @Nickfromwales has fitted one of these I think somewhere ....

[Nickfromwales]

On 24/10/2018 at 07:41, PeterW said:

t’s not necessary and only really if you want the FIT as you could run an isolated thermal store as a buffer and then use it to dump from a section of your PV panels. There are also grid restricted inverters that limit your export below the threshold needed for a larger supply. I think @Nickfromwales has fitted one of these I think somewhere ....

 

Yup, and that means you can choose an inverter that stops anything more than the basic threshold of export that the DNO will allow, therfore you can do away with the expensive 3 phase incoming cable. They will ask to witness functionality of the export limitation function, and may charge for this service. Find out which is the lesser of the two evils ( which is the more expensive solution eg 3 phase will have serious impact on how you inject PV into the 3 separate phases and then how you consume equally across them  which can be a PITA ), a more expensive inverter for one.

However;

 

If you have had a system designed that will need 3 phase for export then something is very wrong. You should be storing everything you produce, so if you've an ASHP then ideally you'd be wanting to storing the excess into a battery storage system to run the ASHP at night (  + cover the base loads in the house from plug-in devices ) and THEN dump any excess into DHW.

 

A Sunamp will store DHW incredibly efficiently but with slightly higher capital expenditure vs a wet UVC. Benefit with SA is no G3 install and nearly zero ongoing maintenance / service requirements. With an UVC you'll spend £1000 every 10 years on inspections alone, ( estimate if you dont have a gas boiler ergo you cant have the gas services and the UVC serviced by the same guy at the same time = single less cost-effective visit to inspect the UVC ) and also there are no complex and expensive controls / valves / discharge pipes from a SA. They also take up about 3 times less physical space vs a traditional cylinder of equal capacity.

First question has to be about fabric, because if you've built a standard B regs UK build then I'd be doing a lot of sums before even thinking about an ASHP .

 

On 24/10/2018 at 07:21, Coops85 said:

We have quite a large large area of PV panels planned as that has been stipulated by the council.  

Ok, but again, if thats just for appearances you can further reduce costs there by going to cheaper, lower output panels and therefore further remove the export / wasted energy aspect. You don't want to pay for an overly expensive system that exports what youve just paid to generate  

[jack]

2 hours ago, Coops85 said:

So am I right in thinking that the PV panels power the ASHP which heats the underfloor heating and the SUNAMP powerd by PV can be used for DHW?  

 

Just to be clear @Coops85, you don't connect the PV panels to just the ASHP and/or Sunamp. PV is connected to the household supply, and anything that is drawing electrical energy within the house will use power from the PV if it's available.

 

You can do things like program your ASHP to only turn on during daylight hours, which will tend to ensure that it's powered by PV if available. But bear in mind that in the middle of winter there are days where you'll generate virtually no PV, sometimes for days on end. In that case, you can't avoid using mains electricity.

 

The aim of the game at the moment is future proofing. Battery storage is still too expensive to be mainstream, but that's changing all the time. Include heavy cabling from the consumer unit to an area where you can one day install batteries (garage, attached shed or workshop perhaps). Also run heavy cables from your consumer unit to anywhere you might one day want to charge a car.

 

As Nick says, the requirement for three phase is puzzling. How much PV has the council stipulated?

 

2 hours ago, PeterW said:

You need to work from basic principles - for example what is the expected heat loss from the building, then you can work out what you need for heat provision through the ASHP. 

 

If you don't know this yet, you can use Jeremy's heat loss spreadsheet to work out an estimate. Come back with that info and people will be able to give more specific advice.

[ProDave]

The trouble with 3 phase, is things like your ASHP won't be, so you will be unlikely to get any where near 100% self usage.

 

If you can stick to single phase, use the HP as much as possible only in the daytime, keep your use of big appliances to the daytime and one machine at a time, and then have a diverter to put excess power into water heating you should be able to use a good percentage of what you generate.

 

If the house is well insulated it won't cool down or heat up quickly, so "allowing" the heating to go off overnight will not be noticed.

 

Don't forget by the time you get your panels, the FIT will have closed to new entrants. So no need to pay an over inflated MCS installer price, just buy them as cheap as possible and get your electrician to connect them.

[Coops85]

Thank you for all your responses

 

On 24/10/2018 at 07:41, PeterW said:

Secondly, how many bathrooms / baths / showers are you planning as that will determine the number of sunamp units you will need. 

 

3 bathrooms with showers of which 2 of those will also have baths.  Plus a downstairs cloakroom.

 

On 24/10/2018 at 10:06, jack said:

As Nick says, the requirement for three phase is puzzling. How much PV has the council stipulated?

 

We need to be carbon neutral and as part of the SAP calculation produced for the detailed planning application granted prior to us purchasing the land it shows a PV of 10.80 kw.  This planning was obviously done to get into the FIT.  May need to revise this slightly.

[jack]

If it's just based on SAP points, you can achieve it with less solar. We have 8.5kW of solar and achieved an as-built SAP score of 100.

 

Take a look at waste water heat recovery connected across one or two or the showers. Even one of those is worth a few SAP points, I believe.

[Coops85]

16 hours ago, jack said:

If it's just based on SAP points, you can achieve it with less solar. We have 8.5kW of solar and achieved an as-built SAP score of 100.

 

Take a look at waste water heat recovery connected across one or two or the showers. Even one of those is worth a few SAP points, I believe.

 

So did you not need 3 phase for 8.5kW? 

 

I am still confused why the council have said we need 3 phase. 

 

How many sunamps would we need for 3 bathrooms? 5 bed, 6 occupants. 

 

Thanks, I will look into the heat recovery between showers. Sounds interesting. 

[ProDave]

2 minutes ago, Coops85 said:

 

So did you not need 3 phase for 8.5kW? 

 

I am still confused why the council have said we need 3 phase. 

 

How many sunamps would we need for 3 bathrooms? 5 bed, 6 occupants. 

 

Thanks, I will look into the heat recovery between showers. Sounds interesting. 

Why do the council think what electricity supply you have is a planning matter?

[Coops85]

10 minutes ago, ProDave said:

Why do the council think what electricity supply you have is a planning matter?

 

It is a condition on our planning permission... probably shouldn't have said council.... I meant planning officers.  

[Jeremy Harris]

I agree with @ProDave, what electricity supply you have is not a valid planning consideration, so the local authority cannot have any say in it and it is not a valid planning condition - ask that it be removed on the basis that it's not supported by any planning policy.

 

The DNO determine how much export current per phase they will allow for microgeneration, although they have an obligation to accept 16 A per phase, under G83, without the customer having to obtain consent.  We have 6.25 kWp on a single phase, and I was told by the DNO that we could have up to 10 kW if we wished, as there are only three properties fed from the run of 95mm² Wavecon cable that runs from the nearest distribution transformer.  I did need to get written consent from the DNO for the 6.25 kWp installation, under G59, but it was a formality and came through very quickly (less than a week).

 

 

[Ed Davies]

I didn't even tell the planners I intended my house to be off grid. Said various things in the design statement about reducing consumption but that was it. Didn't see that it was any of their business how many phases I had: zero, one or three. I can imagine cases where the presence of a wires might be a planning consideration but not their absence or the number of conductors.

 

(Only relevant effect was that it was the BCO, rather than the planning people as apparently it usually is, who referred me to environmental health to discuss the rainwater harvesting. Not a problem, though.)

[Coops85]

 

The above guidance is very helpful.  Around our plot there are a number of houses that have been granted planning permission on the basis that they are built to what used to be 'code 6' standards.  So would have PV on every one - This may have influenced the condition!  

[Jeremy Harris]

When we submitted our planning application in December 2012, the Code for Sustainable Homes was still in force and we were required, by local planning policy, to build to level 5.  By the time our planning application came up for approval, Code for Sustainable Homes had been abolished, so I rang the planning officer and he told me that we no longer needed to build the bicycle store, following that up with an email to confirm.

 

So, any condition that came about as a consequence of needing points to reach any CfSH level became void by early 2013.  There have been no changes to re-introduce anything like CfSH since then, either.  Your planning consent must be after CfSH was abolished, as consent only lasts 3 years, and on renewal after that time any unenforceable conditions should have been removed, as the underpinning policy would no longer be valid.

 

Although it's clearly very worthwhile to reduce energy consumption as far as practical, and fit renewables if possible, there isn't any way that a local authority can continue to enforce a planning condition that was reliant on legislation that has long since been rescinded, so I would be very inclined to ask for the condition to be lifted, as that then gives you the freedom to choose to do what best suits you.

[ProDave]

17 minutes ago, Coops85 said:

 

The above guidance is very helpful.  Around our plot there are a number of houses that have been granted planning permission on the basis that they are built to what used to be 'code 6' standards.  So would have PV on every one - This may have influenced the condition!  

can that even be enforced now as Code 6 does not exist any more?

 

[Jeremy Harris]

7 minutes ago, ProDave said:

can that even be enforced now as Code 6 does not exist any more?

 

 

The simple answer is that it can't be enforced at all, and should never have been a condition in the first place, given that CfSH was abolished years ago.  Our planning officer removed the condition on our draft approval that said we had to get enough points to meet CfSH level 5 just before it was signed and sent to us in 2013, so there's no way that a planning consent that's still valid now, over five years later, can have  a valid CfSH level requirement, as there's no underpinning legislation to back any local planning policy any more.

[HerbJ]

@JSHarris is correct. The relevant legislation was withdrawn in September 2015.

 

We had Conditions  requiring compliance with CfSH Code 4 imposed on our Planning Approval granted in March 2015. We successfully applied to have these conditions removed in April 2015. This is the text we used:

 

The RBWM (Royal Borough of Windsor& Maidenhead) Notice of Decision for Application 15/0xxx  that granted full permission for the replacement dwelling at xxx was subject to two conditions (Conditions 9 & 10) that required the dwelling to  achieve  a Code for Sustainable Home rating of Code Level 4, at the Design Stage prior to the start of development and a Final Certificate, no later than 3 months after completion of the development, respectively. 

As you are probably aware, the Deregulation Act 2015 recently received Royal Assent and will become law in the Autumn (expected September 2015). The Code for Sustainable Homes (owned by the

Government) has been scrapped. When the new bill is made law this Autumn the Climate Change Act 2008 will be amended, which will result in local authorities not being allowed to require a Code level for new planning applications. It is understood that local authorities have been strongly urged not to include any requirements for CfSH code levels in the interim period.

We have  obtained several quotations from suitably accredited consultants to undertake services to assist with discharging Conditions 9 and 10. We have also been in communication with these consultants to clarify requirements, cost and scope. Several of these consultants are now advising us that in their regular contact with other local authorities, they are increasingly being advised  that these local authorties would not be imposing the Code on any schemes with immediate effect AND also strongly  intimating that  if on applications which were recently consented and had such CfSH conditions,  an application to remove the CfSH Code condition (s) would probably be favourably received.  

Have RBWM reviewed their position on imposition of conditions to meet CfSH4 with regard to both future and recent consented Applications? Have RBWM issued any policy or working guidelines on the recent change of legislation impacting their adopted Neighbourhood Plan and/or Supplemnetary Planning Documents?

Considering our approval is just for a single house for our own occupation, would RBWM  favourably  consider a  submission to vary or delete Conditions 9 and 10, based on the recent change in legislation?

Your early advice on this matter  would be appreciated. 

 

The response from RBWM  was rapid  as follows:

There are two ways of progressing this, you could still submit the details required to satisfy the condition as I understand that there are still come companies that will be able to hep you with this, alternatively you can apply to remove the condition from the application as there is now no ability to impose the condition. 

 

We  applied to have the conditions removed and this was approved. It may be very beneficial to you make a similar submission  requesting removal of your condition to your Planning Officer.

 

 

[Coops85]

11 minutes ago, HerbJ said:

@JSHarris is correct. The relevant legislation was withdrawn in September 2015.

 

We had Conditions  requiring compliance with CfSH Code 4 imposed on our Planning Approval granted in March 2015. We successfully applied to have these conditions removed in April 2015. This is the text we used:

 

The RBWM (Royal Borough of Windsor& Maidenhead) Notice of Decision for Application 15/0xxx  that granted full permission for the replacement dwelling at xxx was subject to two conditions (Conditions 9 & 10) that required the dwelling to  achieve  a Code for Sustainable Home rating of Code Level 4, at the Design Stage prior to the start of development and a Final Certificate, no later than 3 months after completion of the development, respectively. 

As you are probably aware, the Deregulation Act 2015 recently received Royal Assent and will become law in the Autumn (expected September 2015). The Code for Sustainable Homes (owned by the

Government) has been scrapped. When the new bill is made law this Autumn the Climate Change Act 2008 will be amended, which will result in local authorities not being allowed to require a Code level for new planning applications. It is understood that local authorities have been strongly urged not to include any requirements for CfSH code levels in the interim period.

We have  obtained several quotations from suitably accredited consultants to undertake services to assist with discharging Conditions 9 and 10. We have also been in communication with these consultants to clarify requirements, cost and scope. Several of these consultants are now advising us that in their regular contact with other local authorities, they are increasingly being advised  that these local authorties would not be imposing the Code on any schemes with immediate effect AND also strongly  intimating that  if on applications which were recently consented and had such CfSH conditions,  an application to remove the CfSH Code condition (s) would probably be favourably received.  

Have RBWM reviewed their position on imposition of conditions to meet CfSH4 with regard to both future and recent consented Applications? Have RBWM issued any policy or working guidelines on the recent change of legislation impacting their adopted Neighbourhood Plan and/or Supplemnetary Planning Documents?

Considering our approval is just for a single house for our own occupation, would RBWM  favourably  consider a  submission to vary or delete Conditions 9 and 10, based on the recent change in legislation?

Your early advice on this matter  would be appreciated. 

 

The response from RBWM  was rapid  as follows:

There are two ways of progressing this, you could still submit the details required to satisfy the condition as I understand that there are still come companies that will be able to hep you with this, alternatively you can apply to remove the condition from the application as there is now no ability to impose the condition. 

 

We  applied to have the conditions removed and this was approved. It may be very beneficial to you make a similar submission  requesting removal of your condition to your Planning Officer.

 

 

 

Thank you very much.  This could prove very helpful!

[Ferdinand]

14 hours ago, HerbJ said:

We  applied to have the conditions removed and this was approved. It may be very beneficial to you make a similar submission  requesting removal of your condition to your Planning Officer.

 

Presumably, @Coops85, you could also simply ignore an unenforcible condition on the basis that they will never be able to enforce it. Your move ... Check, Bet, Fold, Call, Raise , Bluff or Showdown?

 

"The Planning Consultant" (below)

 

 

 

Edited October 28, 2018 by Ferdinand

[Triassic]

22 hours ago, HerbJ said:

We  applied to have the conditions removed and this was approved. It may be very beneficial to you make a similar submission  requesting removal of your condition to your Planning Officer.

 I assume you had to pay the £235planning application amendment fee?

[HerbJ]

2 minutes ago, Triassic said:

 I assume you had to pay the £235 planning application amendment fee?

 

We paid a fee of £195.