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I installed a 4Kw system in November 2015
From commissioning to November 2016 I generated approx 3500Kwh

My electricity bill for
Dec 2014 – Nov 2015 was 1477 Kwh
Dec 2015 – Nov 2016 was 1309 Kwh
and my pattern of usage has not changed significantly in this period - apart from a change from mostly incandescent to mostly LED lighting. Heating and cooking is all by gas so its mostly lighting and domestic power (TV, computer etc)

Obviously I would expect to use some electricity from the grid (because generating and using do not coincide timewise) but I am surprised at such a small reduction especially since the standard estimate (upon which payments are based) suggests that 50% of electricity generated is exported.

So the questions
* Is this reduction in electricity usage 'normal' and if not, what are peoples thoughts?
* If I am exporting that much more than 50% perhaps I could either
- get some electric fires for the winter and save on gas
- should get an export meter installed as well (assuming my FIT company can cope) If I exported the full 3500 Kwh its worth an extra £60 pa (over the 50% allowed)

Thanks for any thoughts
 
Immersion heater permanently switched off.
Actually no immersion heater. Only three wires in the cupboard - two water pumps and an aquastat immersion thermostat

So no possibility of electricity affecting hot water or gas bill.
How easy is it to fit an immersion heater? There seems to be a hole for it with a large nut in place?

BUT: I am still surprised that the reduction in electricity consumption is so small. Any ideas why that might be?
 
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Can you post a photo of the electrical connections? Is it connected into an MCB in your main consumer unit or did the installer add a dedicated CU using a Henley block and tails? It is possible to connect it incorrectly.
 
Can you post a photo of the electrical connections?
You mean like this?
Solar Panels do not reduce Electricity Usage significantly - Confused {filename} | ElectriciansForums.net


There are two sets of panels (12 and 4) so the installed two separate inverters.
The meter above the LH yellow switch is the one I provide readings from on generation
The white cable (bottom Left) goes to the normal electricity meter
 
Can you show the other end of the white cable? That's where the big question will be answered.

We don't use this brand of inverter but the job looks reasonable and the meter reading sounds realistic. I might question whether the ventilation clearance complies with the manufacturer's instructions.

It looks like they've in effect used the AC isolator as a junction box to combine the output of the two inverters. The downside of this is that it's probably not possible to shut off one inverter and leave the other running.

We may have used trunking to hide some of the cabling but sometimes we clip similar to this.
 
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Of course.
Solar Panels do not reduce Electricity Usage significantly - Confused {filename} | ElectriciansForums.net


The installation is on the garage wall so trunking might have looked sligtly out of place!!!
The electricity meter is about 5 yards away from the inverters outside the garage on the wall of the house
 
It looks like the connections have been done correctly.

Has the white cable been clipped to an outside wall? We'd normally use an armoured cable when going externally. We'd also use a thicker one than you have but it's obviously not problematic in your case as generation is acceptable and there's no nuisance tripping.

Are you sure you're reading your bill correctly:

Dec 2014 – Nov 2015 was 1477 Kwh
Dec 2015 – Nov 2016 was 1309 Kwh

These figures are very low. How many people live in your house?
 
Yes - White cable clipped to wall. Neat if somewhat obtrusive job

I live alone.
Heavy lifting is done by Gas (heating, hot water, cooking etc)
Lighting mostly LED

But it still seems to me the reduction in usage is very small - quite probably explained by the shift to LED and random fluctuations.

From what has been posted before, it seems I need to get an immersion heater and that gadget that reroutes generated electricity in order to make better use of the stuff I generate.
 
Generated kWh from solar PV tails off sharply over Autumn into in the winter months. Generation in December is a fraction of what it will be in June. As such benefits from off-setting imported electricity are slim to none, particularly December - early January. This is due to short days and few clear days. Because the sun is at it's weakest generation on overcast days at this time of year can be negligible.
In the Spring, Summer and Autumn it is a different matter, if you are conscious of how well you are generating on a given day (clear/bright conditions) and use your energy-hungry appliances at this time you will see savings.
If you use can maximise your use at this time then export metering would work against you as the deemed 50% would be greater than the real value of your annual export.
 
you should see a bigger reduction than that, though it does depend on your consumption pattern - if you're never in during the day and don't set washing machines etc off to use daytime power and have that low level of consumption then it could be right.

Are you sure your loft light hasn't been left switched on or something like that? It's amazing how much power something like that can end up drawing over a year - 500kWh a year for a 60W bulb.
 
I reckon there's a possibility that you have a faulty import meter in your meter cabinet. I am monitoring some systems in our area (Yorkshire) and they are not starting to generate until 8:15am. That includes east-facing systems with Solar Edge.

I just looked at a couple of sites in Winchester and Gloucester and they don't seem to be active before around 8:00am.

I don't believe that your system was generating enough at 7:45am to cover your baseload and have enough spare to export.

Your meter may have been under-measuring your usage for years which will obviously have saved you £s.
 
I may have the wrong end of the stick here but I have the same size system as you and I have saved loads, the key to me is ensuring that you use the electricity you generate during the day. Easier for us as we have time delays now on our washing machine and dishwasher or my Mrs is at home. In the event of a predicted sunny day I will set them to come on consecutively. I also am on economy seven so if no sun we run the washers at night. As @Leesparkykent has suggested the other sensible move is to fit a solar iboost or similar to divert any excess generated energy to save on heating your water via an immersion particularly during the summer (I haven't done this yet but will be shortly). I wouldn't suggest getting an export meter fitted, instead try to make better use of what you are generating, then you get the best of both worlds.
 

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