Feed in Tariffs

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JohnMathers
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Feed in Tariffs

Post by JohnMathers » Tue Sep 20, 2011 12:07 pm

The other day I was speaking to someone who told me that energy produced by solar panels and not used in the property does not actually go back into the national grid because the technology does not exist to facilitate this. I've done some searching around but cannot work out whether this is correct or not, but was told by a solar pv installer that it is assumed that 50% of what the panels produce goes back into the grid and payments are worked out on that basis.

So what I would like to know is whether anyone knows for definite whether excess energy generated by solar panels on one property does go back into the national grid and is hence available for use elsewhere?

Many Thanks,

John.

SimonWinch
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Re: Feed in Tariffs

Post by SimonWinch » Thu Sep 22, 2011 10:40 am

John

My understanding is:

Electricity produced by PV does flow back into the grid if not used in the property. Meters do allow two-way flow of electricity. There may be an issue where a customer is on a prepayment meter and runs out of credit; in this circumstance the meter will cut off the supply in both directions. But this is the exception to the rule. If a housing authority has tenants with prepay meters that cut off and stop panels producing, less FIT will be gained and the payback on the panels will be lengthened.

As the cost of installing kit to measure the amount of electricity exported to the grid tends to be prohibitively expensive in a domestic property, Ofgem deems that 50% of electricity generated by the PV array is exported, and 50% used on site. So if the customer uses 100% on site more export tariff is earned than should be; if none is used on site then less is earned than should be.

Regards
Simon

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Re: Feed in Tariffs

Post by ALEO Admin » Thu Sep 22, 2011 10:58 am

That's interesting Simon, so this means that the bonus paid for electricity exported to the grid is just based on a fifty-fifty split and the amount you use yourself is irrelevant for most domestic installations? Is that right?

Thanks,
Rob

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Re: Feed in Tariffs

Post by ALEO Admin » Thu Sep 22, 2011 11:09 am

We've also had the following replies emailed through:

Hi

I'm sure you've probably had a flood of replies - but I can categorically confirm that any electricity being generated by PV panels does indeed get pushed back out onto the National Grid to be used somewhere else (via the G83 compliant Grid Tie Inverter that will be installed as part of the vast majority of MCS/FiT installations) .

PV panels can be installed that are 'Off Grid' which usually charge a bank of batteries, though this is much less common (think rural farms in scotland with no grid supply).

The 50% figure is what is paid to the owner by the energy supply company (e.g. Npower etc) for the excess exported electricity.

In theory, the supply company should pay around 3p for each unit of electricity exported. However, due to the upfront cost of installing an extra meter to count those units exported (about £300), rather than meter, the supply company will usually just deem that 50% of anything you generate is exported and thus will pay you ~3p on 50% of what you generate (which is metered anyway).

Hope that clears things up.

Sam Townsend
Peak District Renewables.

And

Hi

The electricity does back into the grid as long as the District Network Operator has been made aware that the property needs to be connected. This should be arranged by the installer of the PV system possibly in the energy provider who is paying you the FiT.

Thanks

Tolu Omideyi
Sustainable Development Officer
Charnwood Borough Council


Thanks to Tolu and Sam for this information.

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Re: Feed in Tariffs

Post by ALEO Admin » Fri Sep 23, 2011 9:08 am

Here's a couple more responses that have come through by email:

Definitely does go back to the grid, the confusion is over the deemed payments for 50% of what is generated.

All because the energy companies do not want to put in a specific meter to measure exactly what is exported to the grid from domestic houses.

Will be different when smart meters come in as the one meter will do evberything, generated, import and export.

Peter Chisnall
Climate Energy

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And
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As an owner of a P.V. installation, and speaking as an electrical engineer I can confirm that any electricity generated by a P.V panel or wind turbine not consumed in the property is exported to the local network and consumed by neighbouring properties.
It is correct to say that for FIT purposes 50%, is the proportion assumed to be exported if no export meter is installed, and FIT (export) payments will be made on this basis.

Kind Regards

Will Pierce
Energy Manager / Rheolwr Ynni
Energy Conservation Unit / Adran Arbed Ynni
Flintshire County Council /Cyngor Sir y Fflint


Thanks to Will and Peter for these responses.

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Re: Feed in Tariffs

Post by ALEO Admin » Fri Sep 23, 2011 9:10 am

And another one from Stuart Davies:

I have a digital electric meter which will not run backwards if the generation is greater than the base-load/current consumption.

If have PV (or wind) with a analogue meter and the generation is greater than the base-load/current consumption then, believe it or not, your meter will run backwards!

Having your electricity export ‘deemed’ at 50/50 would suit most unless there is low occupancy during the day-time (like a community hall for example). Export meters cost in the region £100 and at a rate of 3.1p/ kWh for export the payback is too long for the typical household to justify this expense. Export could easily be calculated with a simple spreadsheet taking daily/weekly/monthly meter and cumulative generation readings.

Best wishes,
Stuart Davies
Senior Project Manager
Severn Wye Energy Agency (Swyddfa Cymru)

JohnMathers
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Re: Feed in Tariffs

Post by JohnMathers » Fri Sep 23, 2011 9:43 am

Dear All,

Many thanks for your replies, I didn't expect such a good response!

Kind Regards,

John.

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Re: Feed in Tariffs

Post by ALEO Admin » Tue Sep 27, 2011 8:49 am

Another good point emailed by Brett Hagen:

I think it’s also worth adding that although they are not measuring the 3p export tariff, of far more significance to the household (after the FiT of course) is the offset energy savings. For every kWh of energy from PV or Wind that you directly use rather drawing from grid energy you save around 12p on your energy bill. This is not directly measured but is obviously reflected in the fact that you are not drawing the energy from your provider.

So it is still important to make use of as much of the generated energy as possible rather then export to the grid and even more so if they are giving you fixed 50% 3p export tariff even if you use the energy yourself.

Regards,

Brett

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Re: Feed in Tariffs

Post by ALEO Admin » Fri Sep 30, 2011 2:55 pm

Thanks to Hazel Hill and Robert Hadfield for the further emailed replies below:

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I can confirm electricity is fed back to the grid a. this can be proved by using an owl monitor which will record the higher electricity movement during daytime when the electricity is being generated.

I have the advantage of seeing the meter is stopped as well.

Hazel Hill

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AND
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I am advised that the reason for this is that currently the meters are not able to process/calculate the amounts hence an assumption of 50%. New smart meters will be rolled out to enable this

Regards

Robert Hadfield
Chartered Environmental Health Practitioner
Melton Borough Council

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