Electricity meter going backwards? – a need for clear guidance from PV installers

by Paula on November 21, 2011

FREE BRIEFING: due to overwhelming interest in the issue of 'electricity usage meters going backwards after PV installation' we have produced a briefing note on the topic. Click here to contact us to request your FREE copy

Listen to me talking to Winifred Robinson on Radio 4's You & Yours about this issue, here.

Curiously, ever since I blogged about my confusion regarding my electricity usage meter running backwards following a solar PV installation, I've received over 50 'search term' hits to my website on this very subject.  It seems like there is quite a lot of confusion out there.

Given I wasn't told this would happen when my PV was commissioned, and, in fact, the electrician seemed to think that backwards running was normal, I have started to ask others with PV systems what their experiences have been.

To be clear, backward running meters only occur if you have an older, analogue style meter, like the one shown below, coupled with a PV system.  In this case, every KwH of generated solar PV will be registered, consumed locally or not,  through the electricity usage meter literally running backwards. If you generate more than you use (a possibility in summer months), over an extended period you could find yourself with a meter reading that is lower than your last meter reading. This is clearly not what is supposed to happen.  Your usage meter should only register the amount of local generated power you use by not turning at all if your generated power meets your needs, and turning more slowly if it partially meets your need and hence your demand on the grid is lowered.

So far I have only come across one other person with an analogue meter plus PV, but she too had no idea that there was anything wrong, and certainly was not told by her PV installer (a different company to mine) that this would need to be changed.  She has just celebrated her first anniversary of PV ownership, and hence a year of very low electricity bills too!

I find it quite astonishing, and not a little remiss, that the installers are not making this situation clear to customers. Is it not part of the basic PV installer training to warn people that this will be the case with analogue style meters, and that they will need to inform their energy company that they will require an upgrade?

I'm also not clear where liability lies in this situation?  When you register your PV system with your FiT payment supplier (which does not need to be your energy suppler BTW) you do state what meter you have, but in my experience, and that of the other analogue meter/PV owner, nothing comes of this.  There does not seem to be a recognition within the FiT payment suppller that this is an issue.  Which is curious given that they will potentially be losing out on revenue if they supply your power too.

So, take the situation of a PV owner running an analogue meter for years before their energy supplier twigs. Will the householder be liable for paying back the actual amount of electricity they have used from the grid but not paid for?  Apart from the issues surrounding the estimating of exactly how much is owed, on which side is the onus to ensure the meter is changed to a digital 'backstop' electricity meter promptly?

If the householder is not informed that it is a problem at the commissioning stage, and doesn't really understand what is happening (I only realised there might be an issue because through the summer I was generating more than I was using, so had a negative meter reading situation) is it their responsibility, are they legally liable?  Or is it the responsibility of the FiT payment suppler to check the meter type? But if the FiT payment supplier is not the energy supplier, then there is no incentive there either?

I would love to hear about the experiences of other PV owners in this situation, so please if you have come across this blog as a result of a search on the subject, leave a comment below or contact me directly through email.  I'd particularly like to hear from anyone who has had this situation for a year or more and what their experiences of dealing with the suppliers has been.

Related blog posts:

Being a PV generator: Lessons I have learnt Part 1

Being a PV generator: Lesson learnt Part 2

Unintended consequences of PV systems and meters running backwards


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