Manual Tracker....?

[Graeme Harrold]

I have a customer with 16 panels and an SMA 4000TL who has asked the question: Can I put another 8 panels up on a different aspect and run them through a timed change over switch that will disconnect/reconnect 1 set of 8. Basically at any one time there 24 panels on the roof of which 16 are connected.....can anyone see any problems with this as technically TIC is not affected due to the change over switch????

 

[Worcester]

Kind of .... WPD state clearly that they want the output of the INVERTER, don't care what or how many panels are attached..

TIC legal definition would be tied to what the inverter could pump out (lots of previous discussions on here about installing >4kWp on East / West arrays)

Is his 4000TL restriced to 16A or is he running the unrestricted configuration? if so does he have DNO approval for >16A ? (4000TL is rated at 4000W [4kVA] nominal output, i.e. 17.4Amps so G59/2 application under todays rules .... )

The problem comes in that you are modifying a completed installation... not sure how the MCS certificate would cope with that

Having said all that, so long as you can get the correct switch gear (need special DC switches especially if doing it every day, else they'll just arc up and get welded closed and then you'll fry the inverter) whose to know?

 

[Earthstore]

As Worcester has said TIC has been discussed before, but it is still unclear, it depends on who you talk to.

Some time ago I made inquiries with the powers to be and they were adamant that TIC was for the panels and not the Inverter, However TEDM who, I have to say, is the font of all knowledge is adamant that it is the Inverter, even explaining why.

The problem appeared to be that they used generic forms for different types of generation, which made no sense at all.

Personally, I would make inquiries with the FIT provider, the DNO, and MCS, and if they all agree then get it in writing before you do anything.

I hope this helps.

 

[Worcester]

Earthstore (as usual) is spot on on this one

 

[BruceB]

Various maxims come to mind here:
- Do not ask the question unless you already know the answer.
- Do not ask the question if you might not like the answer.
- It's often easier to ask for forgiveness than ask for permission.
Sadly, I think asking the questions will open a can of worms and if just one of them gives the 'wrong' answer then if you do it and are found out you are into 'asking forgiveness' territory having already been advised not to do it, which is tricky.
I suspect some people might prefer to fly below the radar, but depends on you attitude to risk and how much is at stake.

 

[Graeme Harrold]

This guy has a neighbor with a 4kW tracker in his field and is impressed with the generated output, hence the question. They both have the same hardware, its just 1 moves.....

Thanks for the insight, I will now go and see how the customer wishes to proceed and let him make the final decision.....

 

[Worcester]

Back in April, ofgem, finally issued the Version 5 of its guidance to FiT Gernators (i.e your client) though they have now clarified it to say that it relates only to Solar PV of >50kWp there are some useful gudiances


The key paragraphs are:

Definition of TIC and DNC
2.17. TIC is defined in Schedule A to Standard Licence Condition 33 as:
"the maximum capacity at which an Eligible Installation could be operated for a sustained period without causing damage to it (assuming the Eligible Low-carbon Energy Source was available to it without interruption), a declaration of which is submitted as part of the processes of ROO-FIT Accreditation and MCS certified Registration."
2.18. DNC is defined in Schedule A to Standard Licence Condition 33 as:
"The maximum capacity at which the installation can be operated for a sustained period without causing damage to it (assuming the source of power used by it to generate electricity was available to it without interruption) less the amount of electricity that is consumed by the plant."

And:

De-rating or altering an installation to cap its generating capacity
2.21. Where an applicant wishes to declare a TIC which deviates from the capacity rating of the generating equipment, it is the responsibility of the FIT Generator to provide us with sufficient evidence which establishes the TIC of the installation. If a FIT Generator wishes to apply for accreditation of an installation on the basis of de-rated or capped capacity equipment, they will need to satisfy Ofgem that the TIC is in accordance with the FIT Order. Further information can be provided upon request by email: [email protected]

In this instance, even if his inverter is limited to 16A, then you may fall foul of:

Eligible Installation
2.4. Where “Plant” is further defined as:
“any equipment, apparatus or appliance.”
2.5. Given these definitions, we expect any application made to us to set out all of the Plant that constitutes the Eligible Installation in question. Furthermore, we expect all of this Plant to have been commissioned and an application submitted (see „How to apply for accreditation section‟, Chapter 4), if accreditation is to be granted.

My underline, as not all of the 'Plant' would have been commissioned at the time of application for the FiT.

 

[BruceB]

I was going to delete my earlier post because I had not read the original post thoroughly enough, but I won't as it has some likes. A switched arrangement of panels at the outset might have been alright if you interpret the legislation boldly. However Worcester's quote above makes it pretty clear that the Eligible Installation would have been altered and therefore you you be stuffed if challenged.

 

[Earthstore]

There is some good advice above.
But why not just add another 8 panels with it's own inverter, a completely new and separate system, the cost of the inverter would be offset as you will not be buying/installing some complicated DC switching gear, the FIT's payments would then help pay for the system, the existing systems FIT would not be affected.
You would have to get the appropriate DNO approval though, and an EPC.

Just one point about the neighbors tracker, how much more did it cost? And what about the long term reliability issues?
It is great to generate a little more but if every 5 years you need to buy a new motor or sensors etc then all your extra FIT payments could be lost.