Exporting your home-generated electricity: deemed vs metered
Posted by Kate Turner on 30 September 2011 at 9:43 am
The benefits of ‘deemed’ export versus metered export of solar PV generated electricity can be a source of confusion for many domestic microgenerators, and recent research conducted by YouGen shows it causes confusion among suppliers too.
In most cases there is a charge for installing and maintaining an export meter so wrong advice can have significant consequences. If you’re not exporting sufficient electricity to compensate for the running costs you could end up losing money.
The government aims that smart meters will be installed in every home by 2019, which will provide some much needed clarity for generators who are exporting to the grid, and will make the whole process of exporting much easier. Currently it is down to the feed-in tariff supplier to ensure the right information is passed on.
A good feed-in tariff supplier will look at your estimated consumption demand to assess whether you will benefit from installing an export meter rather than claiming the ‘deemed’ rate.
[According to Ofgem export meters are optional for installations of less than 30kW, but if you do have an export meter you must use it. If you don't, the amount exported will be 'deemed' at 50% for solar PV, wind turbines, and anaerobic digestion; and at 75% for micro hydro. - Ed]
To ensure you get the best rate of return on your investment, here are the answers to some questions that we’re often asked by our generators. We hope they’ll be helpful to those of you considering installing an export meter.
How much of the electricity I generate through my Solar PV panel is used at my property?
If there is always someone at home then it’s likely that a higher percentage of the electricity you generate will be consumed at the property instead of being exported.
Using as much of the energy you generate at home is not only a very efficient use of electricity, as it reduces the amount of electricity lost in line losses, it also means you will need to import less electricity from the grid, save money on your electricity bills and still get paid the ‘deemed’ rate of export which is currently 50% of your total generation.
I export more than 50% so is it worth me installing an export meter?
Not necessarily. If you’re away from home for most of the day then it’s likely you’ll be exporting more than 50% of your total generation.
Our rule of thumb is that, in most cases, there’s a cost attached to both installing and maintaining the export meter. For the majority of Solar PV generators under 10kW this cost is likely to outweigh any benefit..
Furthermore, it can be a very laborious process to get an export meter removed once it has been installed, so it’s worth making sure you weigh up all the benefits and drawbacks carefully before going ahead.
My installer has already fitted a device that records export. Can I provide readings from this?
No. To claim metered export under the Feed-in Tariff you must have an export meter, registered and installed under the Balancing and Settlement Code (BSC).
This would normally need to be installed by a registered Meter Operator, arranged through your supplier, and you will also need to request a separate export Meter Point Administration Number (MPAN).
Picture by Russ Allison Loar
About the author: Kate Turner is external affairs executive at Good Energy.
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