Are you intending installing some form of storage?

Posted By: owlmanAre you intending installing some form of storage?

No, There would be no point to having this expense as we have 3 phase grid connection used as 3 individual phases, although the supply is not too good as the voltage drops by almost 10% if we get close to our limit of 25A on any phase

Posted By: Ed DaviesDo you have net metering (formally or via the meter going backwards)?

Apparently the meter goes backwards.

Posted By: Peter_in_HungaryApparently the meter goes backwards.

Good. But is that something they're likely to “fix”? Does it happen on a per phase basis or over total consumption? E.g, if you're consuming on phase 1 but exporting the same amount on phase 2 does a single meter sit still or one go forwards and another backwards? I'd guess just one meter.

What are your electricity prices like? Web says about €0.12/kWh vs UK at €0.20/kWh. Is that about right? How do you plan to split the PV across the phases? Any plans for diverters (to heat stores)? Do you have an export limit (e.g., 16 A per phase - which would be a lot with 3 phase)?

While I don't think basic panel prices are going to do anything dramatic I think there's room for cleverer inverters, etc, to do better self-consumption. These seem likely to come along as the FiT bonanza runs out, particularly in Germany. Have to admit, though, that I haven't really looked for a while (being focused on off-grid) so maybe that's already happening.

Ideally, I suppose, you'd like an 3-phase inverter which balanced your consumption across phases.

I got involved with a badly fitted, non FiT, 3Phase system. Find out how your system is currently balanced i.e. are heavy loads/high consumption (hot water store) sitting on one phase with lighting on another. Maybe the third phase has just the kitchen stuff on it.
That would be a very unbalanced system (but might be because your neighbours have things shifted over by 120°) and if you wire in the PV wrongly, you will be exporting and not doing much consuming from the PV.

As for voltage drop, you will get less drop when the PV is generating and you are consuming the home grown. Also, if you get the right kind of inverter (not an SMA, well a UK one anyway), you can change the parameters as to the cut in and cut out voltage. This may, or may not, contravene local electrical regs, but is done over here in special circumstances i.e. very long cable runs from transformer and load. I know it can be done with Fronius inverters, but not sure if they need an 'installer code' to unlock them like the SMAs.

Posted By: owlmanHow much were you considering installing?

panels to produce about 7000kWh annually. This will support 2 houses and the farm.

Posted By: Ed DaviesGood. But is that something they're likely to “fix”? Does it happen on a per phase basis or over total consumption? E.g, if you're consuming on phase 1 but exporting the same amount on phase 2 does a single meter sit still or one go forwards and another backwards? I'd guess just one meter.

I am told it will be 1 meter, I have 4 meters at the moment, across the 3 phases (1 for each house on 1 phase each and 2 for DHW, 1 for each house on the same phase - if that makes sense) I am told by the PV co. that the new meter will sum the 3 phases whatever the direction and come up with a figure, either + or -.

Posted By: Ed DaviesWhat are your electricity prices like? Web says about €0.12/kWh

Correct
Comparative costs per kWh were quoted as electricity = 40 gas = 10 wood = 3 this was from the PV co. he was right about the cost of electricity (I know) and I presume he was correct about the other 2

Posted By: Ed DaviesHow do you plan to split the PV across the phases?

The assumption at the moment is equally split as if it was asymmetrical this would increase the cost of the inverter since this would need to be sized to the maximum PV output .

Posted By: Ed DaviesAny plans for diverters

No, but this might change once the system proposal is on the table and depending upon the export limits.
The aim is to finish the year neutral between production and consumption and the system capacity will be designed accordingly. There is an issue here with surplus production creating problems with the tax man so surplus is not produced. My DHW tank has an (230v) immersion so that I can use that to a) balance the consumption/production or use it to supply DHW if I am away for a bit (for the other house). Ordinarily DHW is produced by a wood gasifying boiler and you can not justify the cost of additional PV for DHW when the alternative is wood from on farm forest.
There is no FIT here but I do get paid for net export but for tax reasons you don't want to get into that. Reconciliation is annual.

Posted By: Ed DaviesDo you have an export limit (e.g., 16 A per phase - which would be a lot with 3 phase)?

Yes, I think its 4kw if you have single phase, above which the electric co. require 3 phase, however I am not sure what the limit is once you have 3 phase.
One issue yet to be sorted is that my consumption is very asymmetrical both in absolute value and over time. However during the initial discussion with the PV company this was not seen as a problem.
At the moment inverters and bidirectional meters or smart meters are a bit out of my comfort zone.

Just looked at PVGIS [¹] for Hungary. Taking a point on the north shore of Balaton to quickly get a clear southern horizon it says 1100 hours of generation per year (facing due south, optimum inclination (34°) - not that inclination makes that much difference to annual generation). Generally it's around 800 to 900 in the UK. Hungary also seems to have slightly better winter generation which is nice - I'm guessing a combination of being a little further south and maybe more clear, though cold, days.

[¹] http://re.jrc.ec.europa.eu/pvgis/apps4/pvest.php

Jolly interesting but:

Posted By: Peter_in_HungaryThe question is - do it now or is it worth waiting

http://www.pv-magazine.com/investors/module-price-index/#axzz4AjhgqVr7

German prices in 2011 December €1.10/kW, in 2016 April €0.58. I make that a reduction to 0.863 of the start price for each year:

>>> exp(log(0.58/1.10)/4.3333)
0.8626881022379741

If one buys 1 kW of modules now it'd cost €580 [¹], leave it a year and it'll cost €500 [²] saving €80. But in that year it'll generate 1100 kWh of electricity saving Ft 44000 = €141.

But there's the inverter and so on to consider, too: how much are they likely to decrease in price? A bit but not so much, I'd expect. Installation costs? Who knows but they might even go up. And if you leave it a year you'll have a one-year younger set of panels. Still, it seems to be better to do it now if it's convenient.


[¹] German mainstream spot prices - retail prices in Hungary would presumably by higher by some multiple so the saving by waiting a year would be larger.
[²] No, that's not guaranteed.

Without doing a fair bit of research to find out how each country/company/trading block installing PV and how man modules are being manufactured and where, it is hard to know what is happening.
What we do know is that RE, especially solar, is being installed at an accelerating rate. We also know that most modules are manufactured in the East.
My feeling is that Europe is now a small market for PV, and generally when you are a small market you get higher prices with inelastic prices (why we can't haggle much).

But as you point out Ed, it is not just the price of all the kit, it is also what that kit can do while you are waiting.
There is also a backstop price. So even if modules grew in the sea and a cargo ship could net them up for nothing, they would still have a price once the have been boxed up, handled and installed. I would not be surprised if a PV module has passed though:
Manufacturer
Large Trader
Smaller Trader
Transport Company
Shipping Company
Cargo Handling
Cargo/Shipping
Cargo Handling
Shipping Company
Transport Company
Large Trader
Small Trader
Transport Company
Installer
Customer

I make that 15 groups, even if they only charge $2/Module, that is still $30, then add taxes/tariffs, say $50, that is $80 for a 250W module (I have no idea what those costs are really, but they will not be minus numbers).

Nothing to stop you looking a 2nd hand panels and inverters is there ?

Panels lose very little performance as far as I can see over time and there are a number of inverters on the UK market at a fraction of their list price .

How much space to mount them do you have ? Is ground mounting an option ?

If you have plenty of space you could always add extra capacity if the price of new crashes in the future.

IIRC the EU put tariffs on cheap Chinese imports to protect the Germans. Once we are out we might be able to get cheaper panels.

Posted By: SteamyTeabut we will not be shackled by EU red tape and environmental law, and I can see no reason to not employ unskilled and inexperienced workers from the ranks of the unemployed and sick "who want to work", they will be grateful for a trainees wage of £3.50 an hour.

No chance - they will be needed to replace all the EU migrants currently working in the NHS and other places once they have been kicked out
Sorry couldn't resist that!!

What's the view on slightly longer term PV price i.e. when will non-silicon technologies e.g. Perovskite kick in, and when will PV shake itself free of the costs of adapting itself to the traditional grid?

Posted By: Ed Daviesit'd surprise me (pleasantly) if somebody suddenly halved the price

Didn't Tesla just do that with battery storage, result of intensive research suddenly reaching 'reliable' status? I'd a thought that's v similar to the non-silicon PV state of affairs.

Not completely true, to get much power out of a PV system the resistance of the load need to be much in real time to the generation of the PV panel(s), therefore a converter/interface is needed between the PV and the load.
Also the DC loads need different voltage and unless you go high voltage the cables have to be very large.