Free solar power system. Is it a scam?

Mcfi5dhc

XRayDave wrote: »

That's a bit of a downer then. I can uderstand why your enthusiasm waned somewhat!

Hmm... maybe I'll not ask for an export meter then. As it stands, if my meter goes backwards, rather than getting a 3p/kWh export "fee" I am getting 13.24p/kWh knocked off my bill.

XRayD

Its a difficult one, I've been thinking about exported power for quite a few days now. There is such a massive difference with or without an export meter, it almost frazzles my head!

The problem is, exported power isn't an overall calculation of the days power, it is an accumulation of individual units created (divided by 1000). So, 1/1000 of a unit is generated, meter decides if it is needed in the house or not, and then either uses it, or exports it.

I.E. you may think the following is right: used 5 units, generated 15 units, therefore exported 10 units, but this is wrong (with an export meter anyway)

What actually happens is:
10:00:00am - panels produce 0.001 of a unit, power not needed, exported
10:00:01am - panels produce 0.001 of a unit, power not needed, exported
10:00:02am - panels produce 0.001 of a unit, power needed, not exported
And so on

For ASG customers, I would consider it far better to have the meter go backwards. For ASG, I would have thought it better to install export meters (but presumably this is part of their sales pitch that homeowners keep more power).

John_Pierpoint

S*d it.
About two years ago EDF (down here in the South East within easy reach of the French north coast atomic power stations) took away my disc meter and replaced it with a small white job the size of a large post card.
This post card has a small liquid crystal display that scrolls round three numbers:
Night time economy 7 usage to date.
Day time usage to date.
Both these numbers added together.
(I have a chart on the meter box door where I write down these readings just in case I need to disagree with the meter reader or the guestimate created by my current supplier)

So I have the worst of all worlds should I go for PV panels on the roof.
No export meter.
An import meter that won't go backwards.
3p a unit for exports on 50% of my generation when I might well be exporting at least 66% of it.

Watch this space.

John

PS: As I understand it there is not a lot of decision involved; the inverter thing, which creates the AC from the DC of the panels, tries to build up a voltage, greater than the nominal 240 volts of the mains.
While kit in your house is using appreciable amounts of juice, it cannot achieve this objective.
However when it gets a few volts higher than the mains the power starts flowing backwards into the mains (making the disc meter go backwards or activating the export meter).

Obviously a disc meter going backwards, especially if one is on day time rate for an Economy 7 tariff, is much more valuable than an export meter clocking up 3p a unit.

PPS A rule of thumb for this green technology is that 10 pounds invested in better insulation/draught proofing gives the same financial gain as 100 pounds spent on sexy green technology; so buildings are meant to have all the insulation measures in place BEFORE being acceptable for "subsidies" for green technologies.
I have a particular problem in that my bungalow home is 50% 1950's with dodgy cavity walls and 50% 1980's then state of the art (lightweight concrete ("foam" blocks) insulated floor slab etc).
Has anyone had the insulation condition of their property queried before qualifying for Feed in Tariff - FiT (or more likely next year's Renewable Heat Initiative/Incentive - RHI) ?

Cardew

It will be interesting to see what the position will be at around Noon when the panels should be producing 2kW to 3 kW and check the main electricity meter readings.

e.g. if the meter reading is several units less at say 2pm than it was at 11am.

Mcfi5dhc

John_Pierpoint wrote: »

An import meter that won't go backwards.

Who says it won't go backwards? It might do? Maybe google it

Irrelevant over the long term though, as we'll all have proper smart meters soon (i.e. digital & smart, not just digital) - I wonder if ASG will be forced to use the real export figures then???

XRayDave

Hi John,

Well, I've already thoroughly double-glazed the house, the walls have cavity fill insulation and I have 200mm of insulation in the loft (well 75% of it at any rate and 100mm on the other 25%) with chipboard flooring on top of that, so the next step was to have either Solar Thermal, an Aerogenerator or Solar PV. As I was directed to ASG by a friend (who, it turns out, wasn't accepted by ASG) who would supply the Solar PV panels for free and any electricity they generated I could use for free, it was a real "no-brainer".

The condensing boiler (11 yrs old and on the fritz) is next on the list to be replaced by an A-rated Combo.

Who knows, I might even fit 100mm slab insulation to the North side of the house & then Tyrolean coat over the top!

I seem to have gotten the energy-saving bug.

So I have the worst of all worlds should I go for PV panels on the roof.
No export meter.
An import meter that won't go backwards.
3p a unit for exports on 50% of my generation when I might well be exporting at least 66% of it.

If you install PV panels yourself then you will get 41.6p/kWh for every single kWh of electricity that the panels produce plus an export figure of 3p/kWh for everything that you generate which is returned to the grid. Thus, if you exported 1kWh of electricity in total, you would get 44.6p for that kWh (someone is gonna correct me on this I'm sure - but that is my understanding).

XRD

XRayDave

mcfi5dhc I hadn't realised that exoprt meters "banked" however little was sent to the grid.

Thanks for that.

XRD

XRayDave

Cardew wrote: »

It will be interesting to see what the position will be at around Noon when the panels should be producing 2kW to 3 kW and check the main electricity meter readings.

e.g. if the meter reading is several units less at say 2pm than it was at 11am.

Cardew,

Yes I could do that if it wasn't for my mother sticking the wshing machine on every five minutes!!

XRD

John_Pierpoint

Hi XRD,

Presumably you don't fancy digging up your floors, insulating them and installing under floor heating so you can run your heating system at 35 degrees.

(Beware of over loading your condensing boiler so that it stops actually condensing and all that lovely latent heat tries to make a snow cloud outside in the garden).

Perimeter insulation might be you next step - insulating the sides of your walls underground to discourage the (say) -5 of a freezing cold night trying to get at the +10 (or more) in the soil under your floor slab? Or have you got strip foundations rather than pad foundations (narrow machine dug trench filled to the top with concrete - rather than - a wider trench with concrete in the bottom and several courses of bricks on top).

Me? In the old half of the bungalow, I've got 6" of insulation in the loft ("how much ! - why are you stuffing it with double the current building regs.?" - waiting for me to sort out the loft junk and hopefully get the next National Power cheeeeep insulation offer. Plus "This ain't going in properly mate" as the back pressure kept on turning off the petrol pump nozzle thing trying to deliver a load of "cotton buds" into the cavity ). Anyone know a cavity fill company prepared to have a go with dark grey nucleated polystyrene beads ?

John
.

Cardew

XRayDave wrote: »

If you install PV panels yourself then you will get 41.6p/kWh for every single kWh of electricity that the panels produce plus an export figure of 3p/kWh for everything that you generate which is returned to the grid. Thus, if you exported 1kWh of electricity in total, you would get 44.6p for that kWh (someone is gonna correct me on this I'm sure - but that is my understanding).

XRD

Splitting hairs it is 41.3p(not 41.6p)

If you have an export meter you do indeed get 3p for each kWh you export.

However it seems that the majority of installations(not ASG) do not have a export meter and their supply company assumes that they are exporting 50% of their generated supply.

So if your panels produced 2000kWh pa you would get 2000 x 41.3p + 1000 x 3p regardless of what was actually exported. That of course could work to your advantage or disadvantage. The larger your system, the more likely to be to your disadvantage.

John_Pierpoint

But if you have a meter that goes backwards you get 50% credited at 3p a unit as, measured by the generation meter, and you don't pay the import cost (say 9p including VAT) of every unit that turned the meter backwards, as well. (assuming you bought rather than "rented" the installation).

Definitely a win win situation;)