ECN Forum Forums General Topics of the Trade Non-US Electrical Systems & Trades New supply -- Awkward location

I agree with Trumpy's call. I've seen a similar situation here become expensive simply because the other property owner didn't want to grant an easement; with that road there, that's not an issue with the poultry farm.
Though....being thoughtfull here... snce 3~ is available, run wires for it at that time. Having 3~ available can only help his property values!

Thanks for the ideas guys. I thought the rough sketch might help you visualize the situation a little better, although as I said, I didn't get the scale quite right so the 3-ph xfmr feeding thr farm is somewhat farther away than the drawing makes it appear.

Bringing power along the road frontage would undoubtedly be the best in many ways, but unfortunately that's the original option which was quoted as "Somewhere in the region of £20,000," which is why we were looking at the other possibilities.


It's not actually a motorhome, but a "caravan" (US = trailer) like the type you find on holiday sites here, although that's of little consequence as far as the power is concerned.

Your idea is roughly what I had in mind, though with the meter at the far end and a sub-feed up to a weatherprrof distribution enclosure. There are already some barns and other outbuildings up near the road as well, so I envisaged small sub-feeds to each of of those, plus a feeder to the existing mobile home until the house is built.

Anyway, the owner's plans are on the back burner for a little while now while he decides what to do, so there's nothing else I can do for the moment.

Finally went back to this place again. All plans for laying in a mains supply have been abandoned.

Running power from the 3-ph xfmr is out of the question due to cost. Getting power from the the xfmr behind the pond is out, as the owner of the land on which that pole stands won't budge in his stance (yet he's been complaining about the noise from the generator again ).

The plan now is to just replace/upgrade the existing battery/inverter setup.

It seems he's been using three or four old car batteries, and running a 5kVA diesel generator to charge them via a small trickle charger. Hardly surprising then that he's running the genset for 6 hours per day!

The "installation" is really nothing more than a lashup, with alligator clip battery connections, undersized wires draped everywhere, and even the ground connection for the inverter is just a large alligator clip on the rod (I suppose I should be grateful that it has even that much!).

I've figure that we should install about 350 to 400Ah capacity of deep-cycle batteries along with a good heavy-duty charger so that the genset needs to be run for a much shorter time. He also has a much smaller 1500VA generator which should be more than adequate.

The existing small wind turbine is only about 10 feet above ground level, so I reckon that by raising that and installing a couple of PV panels we could also gain some useful trickle charge from those as well.

Ideally, I would have liked to change from a 12V system to 24 or 48V, but that would entail replacements for the inverter and turbine/regulator, so we're going to be stuck with 12V.

I reckon a charger which will deliver 30 or 40A into the battery bank should allow the genset to be run for a much more reasonable length of time.

Any recommendations for a heavy-duty charger with appropriate regulator?

Why not a diesel generator with a bit of ooomph?
Example. Honda 10KW, electic start, 230/115v automatic operation, 65dba @ 7m 20hp engine, c.£8000+vat [+ Possible heating operation from the cooling system].
Business use cuts the VAT!
'Red' diesel at £0.30p litre = 3p/kwh gross = 7.5p/kwh assuming normal diesel efficiency, plus the capital depreciation and servicing costs.
Say he got 500,000 kwh over 10 years, and annual sevices cost £100, that would make his electricity about 9.5p/kwh all in. If he nursed the genny for 15 years, he'd do even better. Assumes zero value at end of period.
With no standing charge, and a bit of free heating, that would come out better than the poco! There are cheaper gen-sets on the market. Batteries? in 2-3 years he'd be buying a new set.


Alan

ps. Or a Honda 4kw model, £4250+ vat, same spec as above. A bit small, but with his present lifestyle it might serve.

Paul,
What sort of budget is this guy talking about to do this?.
If you were looking for a charger with that sort of output, you'd probably have to get something like an Industrial Charger, like is used for Charging Forklift and Pallet lifter batteries.
Bear in mind, one of these won't be cheap.
I think the 12V system idea is a good one.
A friend of mine almost has his house running independently of the Grid here in town.
He uses his fire (which has a wet-back) to heat his water and the only thing the Mains supplies is his fridge, freezer and the kitchen stove (which seldom get's used).
All of the lighting is Compact Fluorescent.
Mind you, he has quite a large PV system on the roof of his house that feeds into a couple of HUGE Cells.
Even on an overcast day he has plenty of capacity to run everything he needs to.

I know these 48/24/12v solar/wind systems work fine but the drawback is 2.5-20 times the amperage of a poco supply = heavier wiring. Receptacles, switches, fuses and light fittings etc. hard to source, (witness several threads on this subject recently), and IMO an increased fire risk.
Household machines limited choice. 120/230v ac kit needs an inverter.
Folks get seduced by the 'free power', but the overall cost per kwh soars once you depreciate the generator/ panels/ charger/ batteries over their useful life- particularly the batteries which are the achilles heel.
Given this guy's track record, I'd give his batteries 2 years, tops! I can see them now, with chickens perched on them pecking at the crocodile clips!

Alan

Alan,
I think that you may have the wrong end of the stick here.
I think that what is being proposed is a Battery Bank feeding a Permanently installed Inverter, which would provide the same 230V supply as the PoCo Mains.
Provided that the capacity is there in the Battery bank and in the Inverter(s), I really can't see why this couldn't work.
I've worked with LOTS of 12 and 24V installations in my time and to have a bit in reserve is always good.
With the rising price of fuel in general, I would sort of think that getting away from Petroleum-based generation would be a good option.
The thing is, the place would be wired for 240V as per normal and fused the same but it would be fed from an Inverter.
And before anyone starts to rubbish Inverters as to thier size, you can get them in sizes, up to 150kVA, fully Sine-Wave Compensated, which means you can run a Microwave oven on them properly.

I sure hope so!

The thing is that he's not actually using that much electrical power at the moment. Heating and cooking is done on LP gas, as is water heating. It's really down to just a refrigerator, lights, and a few other intermittent minimal loads, e.g. TV, radio, chargers for cellphone, tools, etc.

Yet he's cranking up a 5kVA diesel generator just to run a trickle charger for the batteries. That's why it's costing him a fortune in fuel. He does transfer some 240V loads direct to the genset when it's running, but I doubt whether the load on it ever exceeds about an amp!

The present inverter is a Swiss-made Domino model, true sinewave output, about 1000VA (I had to replace the eight power transistors in it when they burned out a year or so ago).

I can't see that running a generator all the time could even get near to a sensible cost per unit in this application. I reckon that with an improved installation he should be able to get enough power for a lot of his needs, then just use a genset to boost the batteries if needed.

Oh yeah, he says that the drainage culvert running down the side of the field is pretty fast-flowing and full in winter. I now have the notion of constructing some sort of waterwheel to add to the generating power.


[This message has been edited by pauluk (edited 08-09-2005).]

Paul,
I saw an interesting method of feeding a generator on TV some time ago and would work well, depending on the amount of fall you had to work with.
It meant "collecting" some of the water at the top of the system and feeding it into a length of alkathene pipe (of about 2" dia),running the pipe downhill and then feeding it into and old pump turbine and connecting the armature shaft of the generator to that.

A water turbine to run a generator? Let's try some math to quantify requirements!
Let the average power required be 2.0kw, drawn from an inverter and battery storage charged by a generator and turbine. Let the additive efficiencies of all the above devices = 50%
Then 4.0kw continuous water potential power is required.
4000W = 5.36HP = 176944ft.lb/minute = 2950ft.lb/second

Using a hill to create a head of water for the machine, say a hill 6ft high.( Modest, but this is Norfolk after all!)
176944/6ft = 29491 lb water/minute needed.
= 2950 Imperial gallons per minute= 4,250,000 gallons per day net.
Sufficient energy must remain in the water for it to flow out of the machine, say a gross water requirement of 6 million imp. gallons per day.

Or, try using the kinetic energy contained in the flow of the culvert. Let water velocity = 3mph, (modest walking speed), = 4.4 ft/ second.

KE = 0.5mv2/g ; the mass of water required
= 2x32.2x49/4.4x4.4 = 163lb water/ second.

16.3 imp. gallons per second= 58,680 imp. gallons per hour. Again, additional water is required to drive exhaust stream, say 75,000imp. gallons per hour, 1,8 million imp. gallons per day.

This would dimension the culvert at only 1ft wide by 7.4" deep, with water travelling at 3mph! In practice a combination of its existing kinetic energy plus as high a fall as practical for the turbine feed pipe would be aimed at.

nb. An undershot wheel shoved directly in the culvert will be nowhere near as efficient as a turbine.

Alan