[kris]

 hey  all  bit of an odd one but in need to  know what  other people do in remote areas  and what there power situation is  ill explain

 we currently  run on a diesel generator  and have done for the last 15  years that i know off since i have been involved  with the  family enterprise  we are to far for a grid connection  i have been going over costs with  my dad  and  raised  how much we spent on diesel last year  and wow  we have got to  cut it down  massively  if the diesel price rises then we would have to stop farming anything that uses power any way

 i have found a few  off grid systems  each variety we want to  use solar and some small scale wind  along side the generator

 has anyone else  used this combo  how did you  get on

  currently  we run 25 kwa generator  24 hours a day    the  company we  found  said we could cut our use of the generator  to 3 hours a day  possibly  less with the set up

 is has stored  power of 20kw  18 x 250w solar panles  and  2 x 2kw wind turbines  sounds  alot to me  but   if it does what they say  it would pay for it self in savings in two years surly that cant be right
 does anyone else use  a similar system   or would anyone consider it 

[pgkevet]

That's one of those 'how long is a bit of string' questions. A 25KW genny is a big genny so the need for that implies either lots of heavy farm use or an inability to plan leccy use to be economic. With your setup you can run 4 rings on the cooker as well as the oven, three freezers, 2 fridges, the washing machines, tumble drier, dishwasher, kettle and air con all at the same time I'd guess and even at idle tickover it's a bigger engine than you need.
My OH would expect full power available at any time and refuse to cooperate but turning the genny off late evening and using rechargeable lamps when going to bed would be a simple start. Or even a more sophisticated genny that turns itself off, has a standby battery to supply immediate needs while it fires itself up again on demand....

4.5KW solar panels and 4KW wind power is theory... off grid you'll again need some serious battery storage cos unless you live in 12 hours of daily sunshine and a never ending moderate breeze the reality is you're unlikely to be producing more than 4kw total at any one time and probably a lot less on average. Look at the tessla powerwall as a future option.. http://www.teslamotors.com/en_GB/powerwall

[mab]

hm, yes, a difficult one. Whilst I generate most of my own power from solar/hydro, I'm rather minimalist in terms of my consumption so I don't think my experience is relevant to your situation.

You might try asking on this forum:-
https://www.navitron.org.uk/forum/
as there are several members running full house systems off grid who's experience may be more relevant. Even so I think you would need to come up with some numbers to get any useful answers (like what's your normal daily consumption/ what's you overnight consumption that might be supported by a battery).

only things I could suggest ATM is if you're running the generator overnight for freezers and the odd light then upgrading to modern A+ or better freezers would allow you to shut down the genny for a few hours overnight, and LED lights don't use a lot of power and could be run from a smaller battery system.

Another thought to consider: Someone I know runs his steel barn fabrication workshop off a generator as there's no 3phase in his village for the big welders & plasma cutters; he recently replaced his generator (I didn't think the old one was very old TBH) and the new generator uses less than half the fuel the old one did - apparently the problem with the old generator was that it didn't run efficiently when the load was a fraction of it's full load capability, whereas the new one does. I'm guessing you don't run a full 25KVA all the time so a newer genny might be something to consider.

[kris]

 hi thanks for the messages  i know is how along is apiece of string   been trying to  work it  out  ill explain a little more
 the genny isnt that old its about 4 years old  so its as good as it can be fuel wise  out power is needed mainly during the day  into the early evening .
 we have LED Lighting  already  where we can but we have a lot of poultry  our  power  in the day  for general use is around 10kw for at least 18 hours a day  with out anything else  through the night  the power drops massively  down to  3 kw aprox  i have  turned the power off at night but is causes to many problems the next day with the  timers  of the poultry equipment  and  the heating system  in my house   i have tried some battrey for the house  for lights ect  but  they dont last through the night.  my idea behind the  system  i mentioned was in the day to charge a large battery bank  20 kw in size via solar and cut ind any genny  and only when power requirement is higher  or batteries low  i have room for more solar  evently  but even if the genny  can be switched off for  12 hours  its a start and good enough for me

[mab]

OK, well, my thoughts would still be on reducing useage if possible - though without knowing anything about running a poultry business I don't have a handle on what is possible.


As for timers - well you can get electronic ones with battery backup for central heating at least, which would solve that problem with a.c. shutdown.


But, getting back to the original question of considering the system you have been offered:
Obviously I don't know what the system's going to cost vs running the generator, but one question I would be asking would be regarding the cost & life expectancy of the battery:
Is it a lead acid traction (forklift) battery or a modern Liion?
Is the 20kwh rating refer to 100% nominal depth of discharge (DOD) or to 80%? 50%?. The life of a battery depends on the type and how deeply you discharge it. with lead acid, even 'deep cycle' traction batteries don't like being drained beyond 80%DOD, and even if your stopping at 80%, doing that daily will mean you will be buying a new battery fairly often.
Liion are better at tolerating 80-100% DOD but still last a lot longer if you keep them on shallower cycles, and are a lot more £££ than the lead acid.




As a smaler scale alternative I might think about using the 4kw (or even a bit more) solar via a grid-tie inverter direct to the generator as it would reduce loading during the day, and if it's a GTI which 'backs off' when the ac frequency rises above 50Hz, then in the event that the solar output exceeded consumption, the solar GTI output would automatically reduce once it started to 'push' the generator overspeed (in theory).

[cloddopper]

You say it's diesel ... that will be VAT @ 20 % ... Are you vat registered to be able to claim it back ?


If not , can you get a cheaper fuel oil  such as heating oil ( VAT @ 5 % )  and either run it neat or use it as a diesel paraffin mixture .

If it is a decent genny engine & set up , the handbook for the genny should give you several alternative fuels and & mix ratios as well as different injector pressure settings . If you don't have the hand book then try contacting the manufacturers for the data.