offgrid power

[dannyp]

seems quite a few people on here have played with offgrid power solutions, and a friend current has some quite big offgrid issues. there isn't much avalible in the way of £'s but there is some, and whatever clutter i have hanging about can be thrown into the mix.


got 4x 12v 200HA telecom batterys to potential play with. i have got a few 235w solar pannels that can be chucked into the mix to help top things up but i dought they'll be enough. so it'll be rocking a genorator.

after recomendations for inverters and chargers ect and ideas in general to tryed and tested soultions that can be inplimented on a budget. unfortunatly batterys look like they are going to be a nessary PITA.

got a few small enignes, genorators and marine alternators kicking about that may be of use.


an idea thats kicking about atm

use a UPS type inverter linked into batterys setup as 400 AH @ 24v , feed it on a passthrough with a high ish output petrol genorator ( it's a chonda altho it works well i no longer have any use for it ) to run the relativly high power stuff ( tho this stuff chould proably go stand allone on that genny genny )

4 solar pannels > budget charge controller > batterys

problem with batterys seems to be you need to charge them at relativly low power for a long time, so i thought i chould pull the alternator off that old AC1 ive got and stuff a 24v alternator on it to charge the batterys.

any sugestions on how i'd go about charging gel or AGM batterys with a 24 marine alternator without knackering the lot, but if i can do this i chould easly make the AC1 quite quiet so it chould run though a lare chunk of the day steadly cargeing the batterys

 

[the snooper]

why pull the alternator off it ? you should be able to add an alternator to the ac1 somehow, so as it charges the batteries you can also use the mains power, genny by day batteries by night

 

[dannyp]

it's not me going off grid fortunatly. problem is there is no grid connection nor can there be economicly iirc the quote was in the region of £80,000. thats more than the deposit on a house that is on grid.

the batterys aren't old they are near as dammit new. ( manufacture date 11/15 ) they've been stored fully charged and i can get more of them can they supply the power needed in theory im thinking yes but i don't know hence why i'm asking. what sort of capicity is needed to be practical.

WVO - no thanks buying end of run rapeseed oil in IBC's is cheeper ( even before the hasstel ) but red is cheeper still atm so is heating oil. i was thinking about pulling the alternator off the ac as i'd drop the rpm if just driveing an alternator save a bit of fuel

 

[normspanners]

When my mate had his ac1 running it was relatively cheap to run but best of all was the old pug 205 diesel, we modded the cooling system so that it ran heat exchangers instead of its cooling rad, that then heated his dhw washing bath water and the central heating, ok it was a caravan but it ran a couple of rads, no problems.
the alternator we modded from 12 to 24 by changing the reg the 12v stator/rotor can handle 24v ok most of the lights he converted to led 24v dc and just left the car at a fast idle, it was quiet, key start so his missus could start it and he found it a LOT cheaper than any genny to do the same work, it charged his batteries for the night and he ran any 240 stuff off an inverter, we could have gone further and put a h/exch in the exhaust down pipe to take more heat out, but he found it nearly half the running cost, of anything he tried, took about 1.5 hrs to heat tank full of bathwater and run rads !!
we did think about straping 240v ac genny to it to run washing machine but he now has moved out of the forest into a village.
After all they recon an average car heater is about 8kw !! and that is just the heater matrix nevermind what is being thrown out of the main rad.
With any genny most of the fuel is spent heating the cyl head that is then wasted to free air cooling the thing. So most of you fuel goes to heat the world not you.
At the mo our c/h has gone t's/up waiting for a thermocouple and we are running a 3kw fan heater centrally in the house all night and its keeping it all ok, that along with the log burner at night for 4-5 hrs.

 

[HughF]

you absolutely will have to adjust your lifestyle to suit, unless you have very very deep pockets.

I would suggest the following setup:

500-900ah at 48v (we have 200ah at 48v and are looking to add more)
3kw inverter/charger (we use outback, Sma are very good as are victron and xantrex)
As many solar panels as you can afford
Hardware to mount this lot on a roof (we built a system for a couple of hundred quids worth of unitstrut)
A decent mppt charge controller for the solar panels (midnite solar classic is probably the best on the market right now)
Associated hardware to mount and wire all this lot (a pre-wired e-panel from midnite solar is my recommendation)
A diesel genset, big enough to run all your workshop loads, 1500rpm, water cooled. 12kw lister or similar.

free/cheap but good batteries will save you thousands on the above costs, they are the dominant costs In a system like this.

We have:

Outback vfx3048e
Outback mx60
12 panels giving us 2400w peak
200ah at 48v
Lister sr2 6kw

Average daily use is between 1.5-2.5kw/hr, nearest electrical connection is over 1 mile away and they wanted 80k or something to get us connected.

The UPS idea is a good one, we did this for a number of years. We used APC units as they will power up without an AC input. The built in chargers are low output though. You need a separate charger. I would suggest doing this on the DC side with an mppt solar controller running off a DC genset.

 

[KemppiFrog]

I had several periods off grid. First we had a a Honda genset for any mains powertools or music and oïl lights. Running deliveries every day (flower farm) we kept a couple of 100amp hour batteries in the van and charged them daily. Pumps etc were petrol parrafin and the borehole a Lister diesel turning a shaft drive pump some 50mtrs down the hole. It did 75 cu mtrs/hr and hand starting meant turning the whole system as there was no clutch. Def a two Wheatabix job.

Bit later I bought a house that shared a Lister SRI with the neighbour. Running a washing machine required a note to the neighbour to make sure they didn't do the same. Gas fridge/freezer and gas cooking. Heating by wood stove. Diesel was fairly cheap ( 1/2 the price of petrol) We didn't bother with any other source of lecky as the TV ( one channel in B&W) would run off a 12v lead from the car.

We split up and I gave her the house, bought some land to build, but then had probs with the planners. So built a wooden house that did not require permission, but could not be connected to services. Back to a generator and batteries. I had a little Japanese tractor, so bolted a 3kw 230v alternator to that and parked it a bit away as the single cylinder diesel was a touch intrusive. Gas fridge again and cooking. Gas hot water with a small instant unit. All worked quite well and was simple. My workshop was in town, so I kept the washing machine there along with the phone. No mobile phones then, or 'net.
Then met the wife and we pooled resources and bought a nice house by the coast (on grid). Coincidently, the municipality were desparate to buy my bit of land as part of a new football stadium, so that worked out....

Hi Hugh
Very good up to date system. As you say, lifestyle and expectations have to be adjusted.

At the same time as the above, I looked after the interests of a German shipping co. They had a big house on 8 hectares by the sea and ran their generators 24/7. I used to order diesel by the tanker load. They had very deep pockets.

 

[HughF]

We had a gas fridge, they were extortionate to buy and not very efficient. We now use an off-the-shelf Bosch fridge freezer, a+ rated, it's excellent...

 

[KemppiFrog]

We had a gas fridge, they were extortionate to buy and not very efficient. We now use an off-the-shelf Bosch fridge freezer, a+ rated, it's excellent...

The three gas fridges we had were excellent. Expensive, yes, but when the grid arrived in the second case, people were lining up to buy the 10yr old one. We sold it for more than the new electric one cost. The last one, in the wooden house, I swopped with a friend going off grid for a very good sewing machine. Both happy.

 

[Kent]

One of our neighbours is fully off grid
They have a bank of submstine batteries

I recon you go all out for non electric in the home as regards heating lighting etc them put your own solar in with. Wind if you can afford to buy ( unless you can make)

I don't really envy you our power often fails and we have back up plans but it's not easy

If I was choosing to be off grid I should want it very much off grid so I get the other benefits personally

 

[normspanners]

i was thinking about pulling the alternator off the ac as i'd drop the rpm

as said the ac1 doesnt like running any slower than 1500 and even at 1500 get clogged up.
My view is any genny should be liquid cooled, then you can reap the benefits of the heat produced which far outweighs the electric power it produces (which can turn out to be a byproduct in fact) if you are going to burn fuel get the max out of it, by heating a heatstore at the very least, why burn gas when diesel is cheaper and you get the batteries charged for free, this was proved by swapping from genny to car engine. 4 times the size of engine but much more than twice the efficiency.
I did tests on a genny we acquired as scrap it had done 150hrs total from british aerospace, I think was 700 kva and it ran our granulation plant with rough total 300hp of motors etc, I ran it for one hr and it used 18 -20gal of diesel and produced ample power to run the whole yd, and in that time coz I didnt have a rad, it heated a 600 gal tank of water from 10 deg to 95, it also had a separate turbo cooling section that I cooled with a total loss, mains 15mm water hose through it, and the water was running about 50c
I could'nt measure the heat loss through the turbo cooling but say that was 200gals so in total that was 800gal, raised by 85 degs but it would take almost that amount of diesel to heat that amount of water.
therefore if you can utilize the heat produced it can be efficient, if not it is a waste.
WE didnt endup using it because the leccy company had put a premium on the tariff on the new sub station they had fitted for us and if we didnt use their power the charge per kwhr went up dramatically.

 

[gaz1]

heres mine that im aware of

 

[dannyp]

atm my workshop is near as dammit off grid anyway so no need to worry about that, i have a good for nothing 16A supply there, that's on a meter and charged at proper ouchy rate.
the supply voltage starts at 238v and drops to 170v at 16amps. so it's all wired through a changeover switch through to a 80kw genset. ( it had done much lower hours and was cheeper than the 10kw i was meaning to buy ) so it takes over all the singel phase stuff and prvides 3 phase as well. it's a bit drinky whne your not working it but is supriseingly good when your useing a good chunk of it's output,

 

[dannyp]

so chargeing batterys, for the offgrind location watercooled gensets are going to have to wait sadly the only one ive got would be to big it lives at the workshop and i need it there.

so the littel AC1 with a 24v alternator on it running through an MPPT would be an efective battert charger , then at some point the 24V alt can be moved over to somethign watercooled

heat recovery is a nice idea, when i find a watercooled motor it'll be done, hadent thought about useing a whole car tho, this chould be a proper cheep way fo doing things. literaly grab a car, bodger an extra alterantor on it. chuck batterys n the boot ect and sort out some heat recovery , i like that idea.

 

[the snooper]

so chargeing batterys, for the offgrind location watercooled gensets are going to have to wait sadly the only one ive got would be to big it lives at the workshop and i need it there.

so the littel AC1 with a 24v alternator on it running through an MPPT would be an efective battert charger , then at some point the 24V alt can be moved over to somethign watercooled

heat recovery is a nice idea, when i find a watercooled motor it'll be done, hadent thought about useing a whole car tho, this chould be a proper cheep way fo doing things. literaly grab a car, bodger an extra alterantor on it. chuck batterys n the boot ect and sort out some heat recovery , i like that idea.

using a car engine is going to be expensive fuel wise, ideally you want to match the HP of the engine to what is being driven by it,

 

[GW8IZR]

using a car engine is going to be expensive fuel wise, ideally you want to match the HP of the engine to what is being driven by it,

And you can only transmit a fairly small amount of power on a normal v belt drive to a second alternator so an alternate transmission would be better.. flat belt / multiple v belts etc..

A trailer mounted lighting tower as used on the numerous road works would probably be a better source of power - I had my eyes on a 7Kw electric start unit for a while but my plans changed

 

[rtbcomp]

You could always run a petrol engine on LPG, a diesel on red or perhaps heating oil.

 

[the snooper]

if I was going off grid I would be looking at a lister CS

 

[GW8IZR]

if I was going off grid I would be looking at a lister CS

Father in law used to power the entire farm of one of them with an auto start / stop.. it was very good but then again the load requirement wasnt what we expect today.

That and a Lucas freelight in the lambing shed ..

I did design a solar setup for lambing this winter but her brother decided to stick the ram in a month later and its light enough now with the help of a head torch from time to time.

 

[the snooper]

Father in law used to power the entire farm of one of them with an auto start / stop.. it was very good but then again the load requirement wasnt what we expect today.

That and a Lucas freelight in the lambing shed ..

I did design a solar setup for lambing this winter but her brother decided to stick the ram in a month later and its light enough now with the help of a head torch from time to time.

nice slow plodders, and water cooled

 

[dannyp]

using a car engine is going to be expensive fuel wise, ideally you want to match the HP of the engine to what is being driven by it,

When my mate had his ac1 running it was relatively cheap to run but best of all was the old pug 205 diesel, we modded the cooling system so that it ran heat exchangers instead of its cooling rad, that then heated his dhw washing bath water and the central heating, ok it was a caravan but it ran a couple of rads, no problems.
the alternator we modded from 12 to 24 by changing the reg the 12v stator/rotor can handle 24v ok most of the lights he converted to led 24v dc and just left the car at a fast idle, it was quiet, key start so his missus could start it and he found it a LOT cheaper than any genny to do the same work

contradiction but it wouldn't suprise me if a car engine is more efficent than a singe pot chug chug.