Newbie requiring advice for off grid system (Spain) Europe

SystemSystem Posts: 2,511 admin
Hi All

Hope you can help?

We are looking to buy an off grid solar system and . for use in Europe 230v 50Hz (Spain)
This will be our new home in a few years. after leaving the UK.
Building = remote small stone cottage 750 sq ft. for holiday use. max 1 months use in a continious period. total for the year 4 months.
We can be quite frugal with the Electric. As we have been surviving on a 2.2KVa Generator for the last 15 months. Whilst we restored the house. (Oh what fun)...

It seem that the fridge/freezer on this system is the killer according to my estimations 400w @12hrs
Have i got this wrong. I have a feeling I may have?

See attached file for appliance in daily use.

Appliance* Qty Watts(Volts x Amps) Hrs/Day Watt Hrs/Day
1 water pump 1 600 0.5 300
2 boiler 1 600 0.5 300
3 tv crt 1 150 3 450
4 hifi 1 60 2 120
5 fridge freezer 1 400 12 4800 ?????
6 dvd 1 15 2 30
7 lights 6 18 4 432
8 oven 1 2000 0.5 1000
9 toaster 1 900 0.1 90
10 hairdryer 1 1600 0.1 160
11 hair tongs 1 800 0.1 80
12 hair rollers 1 800 0.1 80
13 electric blanket 1 200 0.3 60
14 microwave 1 1100 0.1 110
15 laptop 1 300 0.2 60
16 washing machine 1 2000 0.2 400
17 Satellite receiver 1 25 2 50
18 Gas hob 1 0 0 0

Total Watt Hrs Per Day: 8522
Total KW Hrs Per Mth (30 Days): 255

Plus the very occasional power tool.

According to the manufacturers website: here are the details.
Energy Consumption kwh / year 288.35

water pump details: Jardino 60.202 (600w)
pulling up 3m from tank.

I am looking to install a full system. inc pole mounted array. poss. tracker. Batts & cables & bits and bobs.
We will also have a key start diesel backup generator 8-10 KVa (Probably an old Perkins/ Lister).1500rmp hopefully, (to be intergrated into the system) mainly to be used in event of system failure or to charge batteries as and when required. Autostart facility would be a nice option.

I have been looking at the Xantrex SW units. And from what I understand these seem to be a fairly reliable unit. that is solid and well built and can also handle high surges from inductive loads/ motors.
Is this a good reliable choice or are there better products on the market.

Should we go for a 24v or 48v System?

Is MPPT the way to go? Outback MX60? Others?

What Have I forgot???? Probably lots

Please let me know if you require any other info.
How do I calculate how many panel & batteries Iam going to require?

London, England
L'ampolla, Tarragona, Spain


  • BB.BB. Super Moderators, Administrators Posts: 32,007 admin
    Re: Newbie requiring advice for off grid system (Spain) Europe

    I would re-check the Fridge numbers... In the US, a well rated fridge/freezer is around 1kWhr per day--4.8kWhrs per day should be way too high.

    255 kWHrs per month should be real doable based on your loads listed... My 3 bedroom home with a family of four in California averages around there--or a bit less. With central heat, fridge, freezer, washer/drier, TV, computers, printers, home network, etc. (heat is from natural gas).

    And yes, you will want an MPPT charge controller for that large of system (basically, anything over ~400 watts of solar panels will be much better and a cost a bit less to build and operate with MPPT--more power from same amount of panels, more panel wiring options, higher panel voltages, less current, less copper).

    You bigger sticking point will probably be the cost to generate 8.5 kWhrs of useful power a day... For a small cottage (no A/C, no central heat, etc.), I would be aiming at 100 kWhrs per month maximum--you may never reach it--but the end system will be about 1/2 the size and cost to build/operate.

    And to do this low of power, you would dump all of the optional electric loads that could be maintained by propane/etc. Appliances like toaster, electric kettle, hair drier, etc. that make heat are very costly to operate on solar PV power. For some things, like a microwave--you may wish to have it for the ease of use.

    One suggestion that may help you decide is to cost out your system over twenty years (or whatever is its useful life for you)--including replacement storage batteries and such. Then divide the total costs by the useful power you will get out of it...

    Here in the US where costs (so far) are typically much less than Europe, my estimates are around $1.00 per kWhr of electricity generated by an off grid solar system (this does not include taxes, interest payments, etc.).

    For you, right now, using solar for your new home only 4 months out of the year, reduces useful power gathering to 4/12 months, or increases your costs by 3x for electricity. Now, your solar power will be costing you $3.00 per kWhr--or for 8.5 kWhr, about $25 per day or $765 per month.

    It may, turn out for now, that you may be better off staying with a good, quite and fuel efficient genset until it is occupied most of the year

    Perhaps with some storage batteries + inverter for off-peak loads--nights and non-meal times. This hybrid system will be much quieter and probably more fuel efficient than just a genset chugging away anytime you need power. Add a small solar panel+charge controller to keep the batteries charged during the 8 months of the year you are not there.

    Poster "Nigtomdaw" here has done exactly what you are looking to do (in Spain). And has started a small solar business on the side based on his own experiences in the region. Look up his posts where he describes (with photos) his installation.

    I am sure Nigtomdaw can give you much better guidance on what to do for your new home.

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • mike95490mike95490 Solar Expert Posts: 9,361 ✭✭✭✭✭
    Re: Newbie requiring advice for off grid system (Spain) Europe
    jodal666 wrote: »
    Should we go for a 24v or 48v System?

    48V if you can. Less amps in the wires, and fewer parallel connections.

    reading the other replies, you may be better off, constructing your backup genset and battery bank NOW, and add solar as you get closer to full time occupancy.

    What about security for all your expensive gear ? Are there neighbors, or nobody ? Do kids (yobs) like to go to the area and party and behave badly ?
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    gen: ,

  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Newbie requiring advice for off grid system (Spain) Europe

    looking over your listed items to run you may wish to see if there are ways to cut back on the power slated for each catagory usage by going with better conservation or better energy saving appliances. go with mppt and no doubt with a 48v battery system. this will be a big step in doing this with much to consider in all aspects of it.
    you are another brit going to spain as nigel (on this forum he goes by nigtomdaw) did this as well. maybe the 2 of you could get together as he may be able to advise you on some of which he has done and can expect more readilly than we here in the states may.
  • nigtomdawnigtomdaw Solar Expert Posts: 705 ✭✭
    Re: Newbie requiring advice for off grid system (Spain) Europe

    John , I live about 15 kms of your Spanish Home south of you near Amposta, Ive just posted a few pictures on my system The Solar Cheese Wedge Shed on the current post of
    Where to put the battery room

    Your more than welcome to come over for a chat when your over here. I use Xantrex gear as you can see, Ive installed Outback equipment also and I agree with previous posters go with 48v base system lots of advantages performance and cost savings over a 24 v system like mine.

    The Xantrex SW systems are being discontinued and the New Xantrex XW system for european use 230v 50hz although in development has yet to be launched.They have the added plus factor of Power Factor Corrected (PFC) chargers.

    PS I run a Samsung American Fridge Freezer (just got to have enough solar and batteries). My Refer is rated at 1.52 kwh per day
    From your details on your fridge 288 kwh a year that gives a 288/365 equals out at 0.79 kwh per day IMHO you need 400 watts of PV to cover just this item,

    If your using this as a holiday retreat only 4 months a year Equipment security will be an issue. I would consider a Gas Fridge which cuts out you main energy hog, they are not cheap to buy but will allow you to run a smaller system. Running costs is approximately a Bottle a month 15 euros. In my humble opinion a couple living over here with all mod cons can get 300 free days of energy to run there home on about 1000 watts of PV without a electric refer of 1400-1600 watts with a A+ refer. Providing you balance out the batteries accordingly. But if your intention is to move out permanently then things need planning more carefully.

    Youve come to an excellent forum with excellent knowledgeable members
  • nigtomdawnigtomdaw Solar Expert Posts: 705 ✭✭
    Re: Newbie requiring advice for off grid system (Spain) Europe

    Hi, ru sorted ? Was looking forward o a coffee or cervesa ?
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