are there drains on my plot?

[Jeremy Harris]

1 minute ago, Amateur bob said:

so its £10/m for cabling? if i dig the trench ill just have to pay for cost of cabling and them connecting it then?

 

 

That's for 11 kV overhead, I think.  230 VAC underground will likely be around £45 to £50/m just for the cable.  Duct would be needed as well.

[Amateur bob]

Just now, JSHarris said:

 

 

That's for 11 kV overhead, I think.  230 VAC underground will likely be around £45 to £50/m just for the cable.  Duct would be needed as well.

ouch, how much is the duct likely to cost?

[Jeremy Harris]

2 minutes ago, Amateur bob said:

ouch, how much is the duct likely to cost?

 

 

Probably around £2/m roughly, depends on the size and type specified by the DNO though.

[PeterW]

1 hour ago, JSHarris said:

 

 

That's for 11 kV overhead, I think.  230 VAC underground will likely be around £45 to £50/m just for the cable.  Duct would be needed as well.

 

Yep - that’s what Western Power said to me for pure budget purposes. Wavecon is about the £40-60/m mark depending on the size needed. Over about 100m you may perversely be better asking for 3 phase as it’s cheaper. 

[Amateur bob]

On 11/10/2019 at 19:24, PeterW said:

 

Yep - that’s what Western Power said to me for pure budget purposes. Wavecon is about the £40-60/m mark depending on the size needed. Over about 100m you may perversely be better asking for 3 phase as it’s cheaper. 

so its 230 VAC underground cable i would need? can i source this myself or do electric company supply it? i have a farm steading with 3 phase next to the plot could i just run a cable from meter to the plot myself(with use of electrician) and burry it? ive a high voltage cable already that runs to my grain dryer, surely this will use far more power than a house?

[Amateur bob]

On 11/10/2019 at 18:26, JSHarris said:

 

 

Probably around £2/m roughly, depends on the size and type specified by the DNO though.

so its 230 VAC underground cable i would need? can i source this myself or do electric company supply it? i have a farm steading with 3 phase next to the plot could i just run a cable from meter to the plot myself(with use of electrician) and burry it? ive a high voltage cable already that runs to my grain dryer, surely this will use far more power than a house?

[Jeremy Harris]

Just now, Amateur bob said:

so its 230 VAC underground cable i would need? can i source this myself or do electric company supply it? i have a farm steading with 3 phase next to the plot could i just run a cable from meter to the plot myself(with use of electrician) and burry it? ive a high voltage cable already that runs to my grain dryer, surely this will use far more power than a house?

 

 

The DNO will supply it, as they have to specify it, plus they are allowed to use cable types underground that mere mortals aren't supposed to.

 

You cannot normally piggy back off an existing supply for a new dwelling as a DIY job, the DNO have to be involved.

[PeterW]

So if you have 3 phase, where does that come to in relation to your build ..? Is it overhead to the farm or underground ..??

 

can you draw a sketch ..? 

[Amateur bob]

2 minutes ago, PeterW said:

So if you have 3 phase, where does that come to in relation to your build ..? Is it overhead to the farm or underground ..??

 

can you draw a sketch ..? 

it runs on an overhead line through the steading and down one poll then goes underground to the neighbours house and steading, the plot im looking at using is about 130m away to the north west of it

[Amateur bob]

7 minutes ago, JSHarris said:

 

 

The DNO will supply it, as they have to specify it, plus they are allowed to use cable types underground that mere mortals aren't supposed to.

 

You cannot normally piggy back off an existing supply for a new dwelling as a DIY job, the DNO have to be involved.

it would be a lot cheaper as i could use a much cheaper cable, is this sort of thing illegal?

[ProDave]

As a rough costing, a local self build had to have 2 poles worth of 11KV line undergrounded.  That cost him £10K with him digging the trenches and laying the duct.  So if you have 10 poles worth that's going to be something like £40K!!! though I guess it won't scale linear.

 

You really just need to get the DNO to come and talk to you and discuss options and give a quote or 2.

 

Extending a low voltage line from your barn is going to be expensive once you work out just how massive and expensive the cable will need to be, to prevent excessive voltage drop.

[Amateur bob]

4 minutes ago, ProDave said:

As a rough costing, a local self build had to have 2 poles worth of 11KV line undergrounded.  That cost him £10K with him digging the trenches and laying the duct.  So if you have 10 poles worth that's going to be something like £40K!!! though I guess it won't scale linear.

 

You really just need to get the DNO to come and talk to you and discuss options and give a quote or 2.

 

Extending a low voltage line from your barn is going to be expensive once you work out just how massive and expensive the cable will need to be, to prevent excessive voltage drop.

how many metres of distance was that 10k? whats excessive voltage drop?

[Jeremy Harris]

9 minutes ago, Amateur bob said:

it would be a lot cheaper as i could use a much cheaper cable, is this sort of thing illegal?

 

I doubt it would be any cheaper, TBH.  The price of cable doesn't vary much, and the chances are that the DNO can supply cable for less than you can buy it.  Looking at the broken down cost for our works it looks like I paid more per m for the 25mm² three core SWA I ran from the meter box to the house than the DNO charged for their 35mm² run of concentric to the meter box.

 

The legality depends how you do things.  If you take a supply from the consumer side of the farm supply, then no, it's not illegal, although you would need to work out a way of being billed from the farm (not hard, just do what landlords do and fit a private meter).  Not a good option, though, as the cable needed will be hefty, for the reasons that @ProDave has given, and the chances are it would be a fair bit of hassle for little or no gain in the long run.  It also ties the house to the farm, which may be OK now, but may well present a problem in years to come.  The farm supply also has to have enough spare capacity to be able to tolerate a ~100 A supply being pulled from one of the phases.

[Amateur bob]

4 minutes ago, JSHarris said:

 

I doubt it would be any cheaper, TBH.  The price of cable doesn't vary much, and the chances are that the DNO can supply cable for less than you can buy it.  Looking at the broken down cost for our works it looks like I paid more per m for the 25mm² three core SWA I ran from the meter box to the house than the DNO charged for their 35mm² run of concentric to the meter box.

 

The legality depends how you do things.  If you take a supply from the consumer side of the farm supply, then no, it's not illegal, although you would need to work out a way of being billed from the farm (not hard, just do what landlords do and fit a private meter).  Not a good option, though, as the cable needed will be hefty, for the reasons that @ProDave has given, and the chances are it would be a fair bit of hassle for little or no gain in the long run.  It also ties the house to the farm, which may be OK now, but may well present a problem in years to come.  The farm supply also has to have enough spare capacity to be able to tolerate a ~100 A supply being pulled from one of the phases.

im sure it would have capacity as the grain dryer runs off it for a few weeks in september, interestingly the farmhouse at my parents farm had the line burried by elect company a few years back and a bit of the cable running down the wall to ground says on it 1000V, this seems high?

[Jeremy Harris]

1 minute ago, Amateur bob said:

im sure it would have capacity as the grain dryer runs off it for a few weeks in september, interestingly the farmhouse at my parents farm had the line burried by elect company a few years back and a bit of the cable running down the wall to ground says on it 1000V, this seems high?

 

The snag is that the supply might be sized to run the grain dryer, so have spare capacity for 11 months of the year, but what's the house going to do for power when the grain dryer is running?

 

The 1000V marking is the cable maximum voltage rating I suspect, not the actual voltage that it's carrying.

[ProDave]

8 hours ago, Amateur bob said:

 whats excessive voltage drop?

You supply is a nominal 230V  Wiring regs dictate that an installation must be designed for a maximum volt drop on lighting circuits of 3%.  So broadly speaking you are allowed to lose 6.9 volts.  Any more than that and it starts to become a nuisance that lights dim when you turn on a big load in the house, and in extreme cases too much voltage drop will render protective devices like circuit breakers ineffective as the fault current won't be high enough to make them trip quickly.

 

So with a long run of cable, you end up having to fit cable that is far larger than what you might think you need just looking at maximum current ratings.

 

This is why the DNO only route relatively short runs at 230V.  Longer distribution runs are at 11KV where voltage drop is very much less of a problem.

[Ed Davies]

In theory, LED lights (other than the “filament” type) ought to be a lot less affected by voltage fluctuations. Is that actually true?

 

Houses with battery/inverter systems in them (Powerwall, etc) should also be less affected. I wonder if a saving in cable cost could ever tip the balance in their favour, economically.

[ProDave]

Yes but the regs still say 3% for lighting, 5% for everything else, but only 1% for solar pv.

 

Even if you take the 5% figure I bet the cable size is going to be quite large.

[Amateur bob]

out of interest how does it work out going "off grid"? i could put solar panels on the roof linked to a battery to store the electric? or does my plot need electric services for planning?

[Alex C]

You would need a battery big enough to last you about 5 months. Solar pv generates half of bugger all over the winter.

[Jeremy Harris]

26 minutes ago, Amateur bob said:

out of interest how does it work out going "off grid"? i could put solar panels on the roof linked to a battery to store the electric? or does my plot need electric services for planning?

 

 

Not normally a problem as far as planning is concerned, as it's not normally a planning issue, other than if there is concern over things like the appearance of solar panels.  The erection of a wind turbine would need planning consent, and without one it wouldn't be that easy to go off-grid without a generator.  A friend who lives near where we used to live went off-grid a few years ago, using a combination of solar panels, a fairly large battery bank and a big single cylinder Lister generator that he converted to run on waste vegetable oil.  The Lister also provide heat for some radiators when it's running.  He runs his Landrover on the same waste vegetable oil, and has an arrangement with a few local restaurants and chip shops to collect their waste oil and process it.  Can always tell when his Landrover drives past, as the exhaust smells like a chip shop.

 

It does normally mean making a fair few lifestyle changes to live off-grid, and the capital cost of the kit needed may well be as high as that of getting a mains electricity supply, so it's really something for either situations where there's no possibility of getting power, or if you have a strong desire to just live off-grid.

[Amateur bob]

12 minutes ago, JSHarris said:

 

 

Not normally a problem as far as planning is concerned, as it's not normally a planning issue, other than if there is concern over things like the appearance of solar panels.  The erection of a wind turbine would need planning consent, and without one it wouldn't be that easy to go off-grid without a generator.  A friend who lives near where we used to live went off-grid a few years ago, using a combination of solar panels, a fairly large battery bank and a big single cylinder Lister generator that he converted to run on waste vegetable oil.  The Lister also provide heat for some radiators when it's running.  He runs his Landrover on the same waste vegetable oil, and has an arrangement with a few local restaurants and chip shops to collect their waste oil and process it.  Can always tell when his Landrover drives past, as the exhaust smells like a chip shop.

 

It does normally mean making a fair few lifestyle changes to live off-grid, and the capital cost of the kit needed may well be as high as that of getting a mains electricity supply, so it's really something for either situations where there's no possibility of getting power, or if you have a strong desire to just live off-grid.

ive mabye underestimated the cost of panels the way i was looking at it say it cost me 10k for them, id have no electric bills to pay once its up and running plus i could use electric to heat the house, or an air source heat pump?

[Jeremy Harris]

6 minutes ago, Amateur bob said:

ive mabye underestimated the cost of panels the way i was looking at it say it cost me 10k for them, id have no electric bills to pay once its up and running plus i could use electric to heat the house, or an air source heat pump?

 

Solar panels only work well when you don't need heating, and don't need much lighting.  Generation from them pretty much falls off a cliff in October, with very little being generated over the winter months, and doesn't pick up again until the Spring.  As most people use more energy in the winter than they do in summer, this leaves a gap of several months of the year where there will be an energy shortfall, which means using something else if off-grid, like a generator, wind power or hydro power.

[Amateur bob]

14 minutes ago, JSHarris said:

 

Solar panels only work well when you don't need heating, and don't need much lighting.  Generation from them pretty much falls off a cliff in October, with very little being generated over the winter months, and doesn't pick up again until the Spring.  As most people use more energy in the winter than they do in summer, this leaves a gap of several months of the year where there will be an energy shortfall, which means using something else if off-grid, like a generator, wind power or hydro power.

i didnt think of this, is a generator a viable idea? we have one on farm but it runs on diesel and sounds like a tractor when running

[Jeremy Harris]

1 minute ago, Amateur bob said:

i didnt think of this, is a generator a viable idea? we have one on farm but it runs on diesel and sounds like a tractor when running

 

Generators are viable, but they do need attention, they cost a fair bit to run and maintain, and they can be noisy.  There are some very reliable units around, like the big, heavy, single cylinder Lister ones.  They can be silenced fairly well.  The friend who runs one has it in a block built shed, with a water jacket around the exhaust and a 50 gallon drum, cast into concrete underground, as the silencer, with a flue pipe leading up from that through the roof of the shed.  You can hear it running when outside, but not from inside his house.  The big advantage of these heavy Lister engines is that they last decades, and just need a bit of oil, decoking every now and again and their fuel system looked after.  There are several Indian companies still making these Listers, so spares are easy to obtain.

 

Not something to be entered into lightly, though, as you need to be prepared to look after the thing, service it, etc, as you will be relying on it for power through much of the winter.  There's a chap up the top of Raasay that has been living off grid for many years now, and who has a good blog on his off-grid adventures and life in general, Paul Camelli.  His blog is here: https://lifeattheendoftheroad.wordpress.com/  Worth reading and digging out his stuff on generators, wind power, solar, batteries, hydro power etc, as he's learned a lot through experience and recorded most of it over the years.  He's off-grid because there's no possibility of getting power up to his remote corner of the island, but has managed to build a new home recently that works well, with all mod cons, despite the lack of mains power.