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Re: Electricity Meter.

Posted: Thu Apr 05, 2012 5:58 pm
by gramm71688
Back in November I had Solar Pv panels fitted 3.5Kw.

The question I would like to ask is I have noticed my energy meter actually goes backwards when I am not using the energy produced, by this I mean the numbers go back. Is this normal and how do the energy providers view this? What happens if the meter reading goes back further than a previous meter reading?

Re: Electricity Meter.

Posted: Thu Apr 05, 2012 6:01 pm
by Montala
Perhaps I have missed something, but what does this have to do with the Raspberry Pi?

Surely it should have been posted in the 'Off Topic' section... if not on a different website altogether!

Re: Electricity Meter.

Posted: Thu Apr 05, 2012 6:14 pm
by Phil Spiegel
Definately the wrong place, but a quick answer is to contact your electricity supplier and get an Export Meter fitted: It may take 6 months to come! (Also check to see the numbers go back, and not just the disc! - I was never sure, as I never watched it for that long!)

There are 2 tariff arrangements at present - in one you are paid for what you generate, and then also for what you export, and in the case of not having an export meter, some assumptions are made.   You have 3.5kWp installed.

Of courser, if you had them installed as part of a deal where the panels are actually owned by someone else, you'll have to look at your agreement with them; it may be simply free solar electricity you use, that you get, and you pay for what you 'import'.

Re: Electricity Meter.

Posted: Thu Apr 05, 2012 6:46 pm
by Gert van Loo
Moved to off topic as it has no direct (or even indirect)  relation to Raspberry-Pi.

Re: Electricity Meter.

Posted: Thu Apr 05, 2012 7:09 pm
by Phil Spiegel
When I went to the OP I hoped it was going to be a suggestion for using the Pi to monitor the Mains Frequency variations to determine Grid Loading - and which could then be used to intelligently control the loading by switching on/off non-critical devices: ie delaying when an immersion heater or underfloor heating would switch in until such time as the frquency rose indicating a lightly loaded grid:

http://www.dynamicdemand.co.uk/grid.htm

Re: Electricity Meter.

Posted: Fri Apr 06, 2012 10:18 pm
by spamel
I work for an energy company, and this can be a problem for you as your readings could completely go to pot if you are one of the older meters. For instance, say your meter reading is 99999 and you use 2kW then you reading would be 00001. Then, you generate 3kW through your PV panel and that puts it back to 99998. A reading is then taken, and by all accounts you have gone round the clock and back to 99998! Big bill coming! An export meter does need fitting, but you should also have an up to date digital meter fitted amd make the company aware you have pv panels fitted. They should know on average how much you use anyway from previous bills, so if it is wildly different then it shoukd ring alarm bells, but it is probably automated these days!

Re: Electricity Meter.

Posted: Sat Apr 07, 2012 8:18 am
by Phil Spiegel
I agree: it was their contacting US that actually triggered the process for getting the export meter: we believed this had already been arranged through our installer ... but whether due to crossed-communincations / being out-of-area, they didn't seem to have made contact with the correct part of our supplier.

The first question we were asked after a 'high' winter bill was had we installed a hot tub? ... actually we had, so that was probably the prime cause ....but we opted out of waiting months for the meter to be 'calibrated/checked' and went for the Export asap meter with only a few more months delay.  But in those days, you only 'earnt' what you exported; now we get a small amount (Not as much as recent installations!) on what we generate - even if we then use it ourselves; which has made replacing (or rather, not reinstalling in an extension) a 95% efficient condensing boiler, with a 100% efficient electric boiler a more economic proposition - especially when installation and annual service costs are considered!

OT: Considering overall costs incuding servicing and fire risks and streetworks etc, having gas in individual homes (in new-build) is not as cost-effective as district gas-powered electricity generation and solar panels on homes! ....even if you don't get a 'dual fuel' discount'.

OT2: (Before the drought order): When reinstating the Hot Tub this winter, we lined the sides and floor with 50mm rigid-foam (building) insulation - reducing the volume and mostly the heat loss - a great improvement, we think, in energy efficiency!

Re: Electricity Meter.

Posted: Sun Apr 08, 2012 4:05 pm
by reiuyi
You're supposed to get paid for providing excess energy back into the powergrid. Contact your energy provider to get a deal on this.

Don't expect to get more than a couple of cents per kilowatt (this is so stupid, they're basically reselling your production to your neighbours with >2000% profits)

Re: Electricity Meter.

Posted: Sun Apr 08, 2012 5:22 pm
by Phil Spiegel

You're supposed to get paid for providing excess energy back into the powergrid. Contact your energy provider to get a deal on this.


We're in the UK, and have been generating at home for about 5 years.

During that time the rules have changed, and depend on when you started! We are now paid for BOTH generation and extra for Export.

We just caught the end of a period of 'government'-subsidised intallation: And Only paid for EXPORT and at the same rate as we paid for Import.

NOW 'new' providers (probably buying cheaper equipment due to progress) get paid for What they Generate at upto 45p/kWh (approx figures for last year, but now lower for more recent installations), and a bit more for actually exporting it. - but no subsidised installation.

Many companies have fitted panels 'for free' - getting their return mainly from the Generation-Payment, and allowing the householder 'free use' of the generated electricity. [Don't know what they pay for Imported power - as normal?].

As a result we now get payment for what we generate, even if we use it ourselves - but at a much lower rate than above - but still making it economical not to reinstate the condensing gas boiler with its high installation and maintenance costs!

Re: Electricity Meter.

Posted: Sun Apr 08, 2012 6:25 pm
by reiuyi
Phil Spiegel said:


NOW 'new' providers (probably buying cheaper equipment due to progress) get paid for What they Generate at upto 45p/kWh (approx figures for last year, but now lower for more recent installations), and a bit more for actually exporting it. - but no subsidised installation.

Many companies have fitted panels 'for free' - getting their return mainly from the Generation-Payment, and allowing the householder 'free use' of the generated electricity. [Don't know what they pay for Imported power - as normal?].


This is a really sweet deal, you know! Though I'm unsure of tax constructions like this and how viable they are in the long run (will it still exist after the next cutbacks?), the way you present it seems very positive

Which kind of raises the idea of "home-production" being way more viable than the traditional view of coal powerplants hundreds of miles away spewing toxic fumes into the atmosphere in the middle of fields where cattle grazes. Though this thread isn't really about discussing what toxic gasses our food inhales before we eat it