13 replies to this topic

[saffire]

Hello All

Just trying to set up utilities to connect to my 'mobile home' and am having a bit of a nightmare - no mains sewer or electricity available.
I Think I have a solution to the sewer issue which just leaves power...
The options as I see are this -

1. PV solar panels - On the plus side no planning seems to be needed if attached to the roof of my home. On the minus side - very expensive (£12k for 2kw) and unproven technology. The official blurb offers attractive incentives but having looked at the actual power produced I dont think they will provide enough energy - and or course they dont work very well in the winter or at night!

2. 3 kw wind turbine - plus side my site is quite windy. attractive gov incentives. Minus side - planning required - giving the officers the opportunity to poke their nose in and interfere. Also quite expensive (£13k) possible noise and flicker. danger to birds.

So now I am looking at a Generator plus batteries. costs less at around £6-8K.(10-12kwh). Modern ones operate relatively quietly. LPG seems to be cheaper to run than petrol or diesel.
The plan would be to run generator while at home using appliances and to charge batteries. then switch off during night and when away from home to allow fridge to run off battery store.

Does anyone out there have any experience of off-mains energy ? I would welcome any thoughts advice or comments.

Thanks
saffire

[Groundhog]

Hi Saffire its really down to your demand for power,or need for it.You can put together a wind turbine,solar,battery bank,inverter and genie for around 3k.Wind turbines are great if you have a good site with clean wind,get your hands on a little aeronometer and wander around where you think you want to site it see what readings you get a 24v or 48v 1kw turbine and a decent enough battery bank backed up with a 180w solar panel could keep you going and as you say run the genie at peak load times this will charge your battery bank through the invertor at the same time.Dont forget the cost of running the genie tho !! Look into grid tie in you can get paid at the moment for every kw you produce even if you are not linked to the grid think they pay you 47p a unit and it only costs 17p to buy in(dont quote me on that).An ideal site wind power in the winter solar in the summer genie as back up.

[happymanoftheworld]

Hi Derek O
Did you really mean turbine, solar, battery bank, inverter and generator for £3k? ---- I would have thought quite a bit more expensive. Curious. Have a great day!

[happymanoftheworld]

OOPS! Meant to add - I have used an internal portaloo - about £70 and ORGANIC chemical solution £9.95 - last a long time - and find it great..... especially as I don't pay sewage rates nor septic cleaning. That has been the situation for 6 years now. And no smell --- honest.

[Groundhog]

Only talking about supplying a mobile,you could spend as much as your budget allows ,turbine controler,dump load £1500,diesel 5kv genie £500,batteries £500, solar and controler £500 demand is the key factor and battery bank amp hours,you can have one solar panel to trickle your battery bank and another to work power a smaller battery to work a 12v lighting system or 12v fridge,loads of combinations.Had a conversation with a guy who was living in 2 mobiles with his family both his kids had separate panels a battery and small invertor along with a charge controler that showed how much power was left in the battery,it was then up to them how they used their own power,be it playstation or stereo etc

[happymanoftheworld]

Ha! I get it now ------ you use quite low power generationof your own but if you are using say 2 fires and cooker .... 5kw. You use the mains but repay some of it back at a profit.... the monetary ratio being about 3 to 1 so if I use the 5kw for 2 hours then 10 hours of my supplying 1 kw would break even. I think I get it?????

[Hobbit]

Can I make a few recommendations based on my personal experience?

Firstly, I strongly recommend the use of traction batteries such as those found in forklifts etc. Most so-called deep cell batteries are pretty short lived affairs whilst the traction batteries are designed for heavy discharge and fast recharge, with a lifespan of 10 - 15 years. Normal batteries will give you between 100 - 150 recharges under those sort of conditions, with performance drops all the way. Traction batteries aren't cheap when new but I bought 450amphours worth of cells for £350 from ebay, far less than the price for equivalent capacity 'leisure batteries'. Mine were 5 years old and with proper maintenance should give me years of use. I run a 4kw inverter from them and can even run a washing machine aswell as all the normal household appliances.

Secondly, with regard to charging, I simply rigged up two 150amp car alternators to run off an old Lister D stationary engine. Engine was £85, alternators were £75 each, plus a couple of hours knocking up some bracketry. No need for any regulating gear, charger-inverters, dump loads etc. The alternator's internal regulator does everything and runs most efficiently at 2000rpm, so simply set the pulley gearing accordingly. My Lister runs at 750rpm, with it's large pulley wheel spinning the alternators at about 2500rpm. It only takes an hour and a quarter to fully charge the batteries, and costs about £1 in fuel. Sounds much nicer than a modern fast-revving generator! Of course the vintage engine isn't mandatory, it's just my personal preference. Any stationary engine will do, or even a car engine. Using an engine with a starter motor will also allow you fit an autostart box which will sense when charging is required and automatically start up your generator setup.

Hope this is useful to someone.

[Groundhog]

Hi Hobbit
Good idea about the alternators,you would have to run my genie for 10 to 12 hours to recharge battery bank,not efficient as I am effectively running a large genie to power a battery charger.
Another good source for the batteries are ones they have used in telephone exchanges as back ups.Have been told you are better off having lots of medium sized solar panels instead of a larger capacity one because if the big one fails you have lost all your eggs so to speak and they cost more to replace.You can purchase water flow generators but I seem to remember you need a reasonable flow rate per minute,but if you had land close to a water course am sure with somesort of header tank and reducing pipes energy could be produced to power up another bank
HMOTW sorry didnt explain myself very well, just meant to supply ones own electric and be self sufficient so you have to be prudent on how you use it.The Genie hopefully is used the least but when you do use it it would be of an evening when your lights are on,tele,do you washing and drying at the same time and also by having it running you are charging your bank and not drawing from it.Then during the day your bank trickles supply to your fridge etc.The grid tie in is a bonus thing it just means that if you are to far away from the grid every kw you pruduce from your energy set up is recorded on a meter and you get paid for this,even tho no one takes it you are producing power that they could have its not your fault they cant get.I would be interested to hear from anyone who better info on this,from what I have read it sounds expensive because at the moment it is companies trying to sell you all the equipment and installation that are pushing scheme,whereas I think that in theory even if your set up only produces 45kw you get paid per kw. I stand to be shot down in flames over this one !! Can anyone enlight ?

[treebloke]

I have read all of the posts above but dont really have a clue what sort of electricity systyem to have and how much power I will need. I will be living in a static caravan, so lights, fridge, water heater and computer will need to be on electricity. I am hoping to install a wood burner for heat but ill leave that for another thread. No washing machine as that will be done off-site.

So based on the above how do i work out how much power i will need and therefore if my budget will allow for a large enough solar / wind power system?

I guess if I use wind / solar power I will need a generator for back up?

Over a two year period will it be cheaper to invest in a solar / wind powered system or use the standard gas system in the static for the fridge and water heater with everything else on a generator?

[saffire]

Hello Treebloke

If you are still having problems sorting out what you need and need to talk through a few ideas etc send me an email.
I have been in same situation as you. There is so much information avaiable that it seems impossible to make any sense of it.
I have made quite a few mistakes along the way but have now reached a point where I think I have got it sussed.

Good luck
Saffire

[saffire]

P.S.

If at all possible do not try to heat water usung batteries/inverter. It will use so much power drain your batteries and may even trip the inverter out.
You mentioned using a wood burner - try to get one that has a back boiler which will heat your water for free - or install solar water heating panels.

Regards
Saffire

[treebloke]

Hi Saffire,

Thanks for the info / tips. ill pm you.

If anyone else has anything they can add that is also much appreciated. The more info the better:)

[bramblebasher]

Hi,

I have a 7kw perkins diesel generator which is converted to run on veg oil, or veg oil diesel mix. 1500rpm, extremely quiet, extremely rugged. The electricity is used to heat a large body of water to 35 degrees celcius, this body of water is then used in under bed heating systems in the polytunnel, it also runs a victron inverter/charger to power 1000 amp hours of batteries in 24v configuration. The exhaust heat is captured through an exhaust gas heat exchanger and heats the domesic hot water tank to 65 degrees celcius, any surplus heat from the EGHE is then bypassed to the thermal store in the polytunnel. The engine heat (it's radiator liquid cooled same as a car) is ducted straight into the polytunnel for helping winter salad production.

That works pretty good and is costing about £2 a day to run as the majority of the calories are free from pub! The rest of the calories are red diesel. It is on for around four hours a day and that provides an awful lot of heat and power.

Lpg will cost you more than red diesel, but an lpg engine is quieter and cleaner, still go 1500rpm though IMO.

It's not everyones cup of tea to go to this extent for a bit of power!

Good luck.

Brambles.

[treebloke]

Hi Brambledasher,

That seem like a lot of hard work, I think I need something a bit simpler to start off with but thanks for the input, its something to bear in mind for the future.