PV garden installation annual figures?

edited 6 October 2012 at 6:07PM in Green & Ethical MoneySaving
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WigWig Forumite
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edited 6 October 2012 at 6:07PM in Green & Ethical MoneySaving
This will be for North France, France has no FIT for PV
Beginner's questions:
A Sanyo 250W panel costs £370
http://www.swithenbanks.co.uk/shop.php?action=full&id=11293

If I did something like this - with 24 Sanyo panels
300px-Solar_panels_in_Ogiinuur.jpg
in the garden (Facing South) very similar weather to South West UK.

How many kwh would be generated on average per year?

Because France does not have a FIT for PV would I feed the grid at all or would I be storing and using my own power?

Which is cheaper to set up, feeding the grid or storing/using off grid?
How much room do the batteries take up for 'off grid'?
How much do the batteries cost?

I guesstimate the annual consumption of the house to be 4,000 kwh per year.

Because there is no FIT I would not want to generate more than I need.

I know you don't know about France, just give your best answers as though it was for UK and UK did not have FIT.

Replies

  • edited 6 October 2012 at 7:12PM
    zeupaterzeupater Forumite
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    edited 6 October 2012 at 7:12PM
    Wig wrote: »
    This will be for North France, France has no FIT for PV ....
    Hi

    I'd look at checking the above, France have a FiT scheme and they seem to have recently announced (4 Oct 2012) an increase in the tariff from €0.175/kWh to €0.184/kWh for sub 100kWp installations, having previously reduced tariffs ... (http://www.rechargenews.com/energy/solar/article324655.ece)

    I can't find official details but check these sites, although the latest announcements/changes seem to be missing ...

    http://www.pv-tech.org/tariff_watch/france
    http://en.wikipedia.org/wiki/Feed-in_tariff#France

    ... As for generation, facing South with no shade you'd probably be safe assuming somewhere around 1000kWh per year for each kWp installed in northern France, but it would be better to calculate estimated generation for the actual location using PVGIS (http://re.jrc.ec.europa.eu/pvgis/apps4/pvest.php) ...


    HTH
    Z
    "We are what we repeatedly do, excellence then is not an act, but a habit. " ...... Aristotle
    B)
  • WigWig Forumite
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    Thanks,

    What's a kWp and how are 250W Sanyo panels converted to kWp?

    Good to know there is a FiT in France. and annoying that it is half the amount for ground installs. But in one sense I don't care what the FiT is all I want to do is generate enough for my own use.

    I assume that doing it off grid is more expensive than connecting to the grid?

    You see, if the FiT is 10c per kwh for ground installs and leccy costs say 15c per kwh from the grid, if I consume 4,000Kwh per year and I feed the grid 4,000kwh I will have to pay 200 Euro per year, so I'd only be saving 400 Euro a year, whereas if I was off-grid I would save 600 Euro a year. Unless my assumptions of how feeding the grid works are all wrong.
  • edited 6 October 2012 at 8:08PM
    Kernel_SandersKernel_Sanders Forumite
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    edited 6 October 2012 at 8:08PM
    Kilowatt peak. It's the total of the maximum number of watts that each string of the inverter can generate

    You could increase the production dramatically by having a steerable array, but unless somebody is at home all day to keep moving it, the costs of a motorized system might outway any extra FiT benefits from the meagre French scheme.

    Even if you are in all day, you won't be able to use much more than half that generation unless you have an auxiliary system for diverting power to the immersion heater. As for storage, I believe that the battery that can store more than its own value in electricity (over its lifetime) has yet to be invented.
  • Martyn1981Martyn1981 Forumite
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    Wig wrote: »
    This will be for North France, France has no FIT for PV
    Beginner's questions:
    A Sanyo 250W panel costs £370
    http://www.swithenbanks.co.uk/shop.php?action=full&id=11293

    If I did something like this - with 24 Sanyo panels
    300px-Solar_panels_in_Ogiinuur.jpg
    in the garden (Facing South) very similar weather to South West UK.

    How many kwh would be generated on average per year?

    Hiya Wig, first thing I'd do is stop looking at the Sanyo @ £300 plus VAT and look instead at the cheaper 'normal' panels such as the Suntech's or YingLi's which are half the price.

    Normally you'd only choose the Sanyo/Panasonic's when space is really tight, as they are physically smaller, so you could squeeze more of them on than a similar 250W panel.

    But if ground mounted, then you might as well go for slightly larger, but also 250W (or more) panels at half the price.

    Mart.
    Mart. Cardiff. 5.58 kWp PV systems (3.58 ESE & 2.0 WNW)

    For general PV advice please see the PV FAQ thread on the Green & Ethical Board.
  • WigWig Forumite
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    I still need to understand the relationship between the no. of panels (in Watts), the kWp of the inverter and the amount of kwh generated per year? The location is Brittany France.

    I also need to know, when you are on the grid, do you use the electricity that you produce and any left over goes to the grid? Or do you feed the whole lot to the grid and take back from the grid all that your house uses?

    Also If most inverters are not putting out good sinewaves, when it goes into the grid does that not "infect" the grid power in anyway?
  • edited 7 October 2012 at 6:55PM
    zeupaterzeupater Forumite
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    edited 7 October 2012 at 6:55PM
    Wig wrote: »
    I still need to understand the relationship between the no. of panels (in Watts), the kWp of the inverter and the amount of kwh generated per year? The location is Brittany France.

    I also need to know, when you are on the grid, do you use the electricity that you produce and any left over goes to the grid? Or do you feed the whole lot to the grid and take back from the grid all that your house uses?

    Also If most inverters are not putting out good sinewaves, when it goes into the grid does that not "infect" the grid power in anyway?
    Hi

    A 250W panel will produce 250W in peak sunlight test conditions (1000W/sqm) at a particular rated panel temperature (25C) ... four 250W panels will therefore produce 1kW under the same peak sunlight conditions ... 1kW of panels is therefore referred to as 1kWp (p=peak)....

    The 24 250W panels you are looking at will form an array rated at 6kWp, but it will be rare for the system to generate at this level for extended periods, even if in bright sunlight. As the panels warm their efficiency drops, therefore a 6kWp system facing south in sunlight at midday will typically produce between 4.75 and 5.25kW ... in bright cloud probably 1.5kW and in heavy cloud/rainy conditions probably around 150W to 300W, if you're lucky.

    As previously mentioned, you could expect to generate somewhere around 1000kWh/year in northern France for each kWp of installed capacity, according to PVGIS (link given before) some coastal areas could be 15% above this ... try the PVGIS tool and see what it estimates the generation capacity is for your own exact location .....

    When grid connected, if you are generating less than you are using you will be importing the difference, if you are generating more than you are consuming you will be exporting the difference .... ie you will be importing at night and with a 6kWp system, if your consumption is not atypical, you'll likely export in the region of 80% of your average annual generation ....

    A decent inverter should have the ability to almost perfectly replicate the grid conditions and have no effect on the local grid, subject to the local grid being able to cope with the aggregated generating capacity in the surrounding area ... the inverter will need to be specifically certified for use in the country in which it is installed .... this will probably be a pre-condition for connection to the grid and for payment of the FiT ...

    HTH
    Z
    "We are what we repeatedly do, excellence then is not an act, but a habit. " ...... Aristotle
    B)
  • edited 11 October 2012 at 12:18PM
    jimjamesjimjames Forumite
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    edited 11 October 2012 at 12:18PM
    I would be worth checking the FIT eligibility in France. My understanding is that the scheme ceased for new installations.

    As a guide we have 3kWp panels (14 x 215W panels) in SE England and are on target to generate just over 3000 kWh of electricity this year.

    You can see a breakdown on a month by month basis of actual generation here

    http://solar-panels-review.321web.co.uk/monthly-pv-solar-panel-generation.php

    August was a big drop due to a fault in the inverter that was only picked up when we returned from holiday.

    Based on the output we get from our panels and assuming exactly the same setup etc you would expect to get over 6000 kWh of electricity for the first year.
    Remember the saying: if it looks too good to be true it almost certainly is.
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