Solar Panels do not reduce Electricity Usage significantly - Confused

[Rincewindwiz]

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

 

[Leesparkykent]

Do you have a hot water cylinder?

 

[LeeH]

^^^that. And if you do has your gas bill reduced?

We're thinking you may have a iBoost or similar?

 

[Rincewindwiz]

Do you have a hot water cylinder?

Yes.
Gas boiler.
Immersion heater permanently switched off. Not even sure it works!

 

[Leesparkykent]

Well you should install/get installed something like this

https://www.marlec.co.uk/product/solar-iboost/?v=79cba1185463

Any excess generated will be put in to heating your hot water.

 

[Rincewindwiz]

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?

 

[whinmoor]

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.

 

[dansk]

^^ probs on wrong side of import meter.

 

[Rincewindwiz]

Can you post a photo of the electrical connections?

You mean like this?

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

 

[whinmoor]

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.

 

[Rincewindwiz]

Of course.

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

 

[Leesparkykent]

Your main meter has reverse energy detected.

 

[Rincewindwiz]

Your main meter has reverse energy detected.

So I guess this mean the panels are generating more electricity that I am using?
Slightly surprising since the photo was taken at around 7.45am

 

[whinmoor]

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?

 

[Rincewindwiz]

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.