Mains or generator

[warksfarmer]

I can't find a recent thread where this was discussed? but what's going to be cheaper long term?

Mains into a shed at a cost of £5,000 for 200amps, 3 phase and then ongoing billing which we think will be around £300/month average.

Or a purchased generator 200amps or equivalent in kva running off red derv. This would mean buying a fuel tank for it and then building a small construction to securely house the generator and fuel tank as security could be an issue.

 

[TheTallGuy]

If you can get 200A 3ph for 5k, then go that route unless you only have occasional need for power - a 100kVA long run genny will cost quite a bit more to buy and run, plus all the maintenance side of things & security.

 

[upnortheast]

200 A 3 phase for £5000 is a bargain. Knock their hands off before they reprice it

Ongoing costs are cheaper for mains than running a genny

3 years ago ours was £27000 for 160A per phase

 

[Pheasant Surprise]

The genset is only economic if the 3-phase mains costs are astronomical AND your only doing small hours (or using a very small 3-phase set). I'd say your 3-phase costs connection costs are pretty good actually.

A 200A 3-phase set will be around about 150 kVa or 120 kW give or take. Table snuck from the Internet gives a brief view of fuel consumption (I think its a bit optimistic).

On the basis that diesel is rapidly approaching 50p per litre and electricity is about 11p/kWh. Allowing £1 per run hour maintenance on the set the cost difference (at full chat) is around £4 per hour, in favour of mains.

You then need to factor in your purchase or rental price of the set and work out the capital difference against your £5000 mains connection costs too work back to your break even point.

 

[upnortheast]

When we ran the bottling plant on a genny our 30kw unit used about 1 gall an hour which agrees with the table above.
When we got 3ph, diesel use dropped by about 700 litres / month & leccy bill went up by £150 ish

 

[warksfarmer]

When we ran the bottling plant on a genny our 30kw unit used about 1 gall an hour which agrees with the table above.
When we got 3ph, diesel use dropped by about 700 litres / month & leccy bill went up by £150 ish

So fuel use down by £300 ish per month but electricity was about £150 per month leaving a net gain of about £150/month before the elec install cost was accounted for.

 

[TheTallGuy]

So fuel use down by £300 ish per month but electricity was about £150 per month leaving a net gain of about £150/month before the elec install cost was accounted for.

Then factor in maintenance and depreciation on the genny...

 

[upnortheast]

and it`s a hell of a lot easier just pressing the switch, against fueling & servicing the genny.
If the mains go off you have the genny as back up, If the genny goes off you are fooked

 

[Pheasant Surprise]

and it`s a hell of a lot easier just pressing the switch, against fueling & servicing the genny.
If the mains go off you have the genny as back up, If the genny goes off you are fooked

I probably need to recheck my maths, as I recall the last time I did the costing exercise against mains, mains was way cheaper.

There's a reason why there aren't millions of diesel sets chugging away everywhere (where mains is cheaply available). They are an expensive way to generate power.

 

[Exfarmer]

It can make a huge difference to the calculation depending on the use of the power.
At the time I priced pumping with diesel opposed to putting in a mains feed and we believed that diesel pumping was cheaper than electric without inputting the cost of supply. However the convenience of having a simple switch on off with virtually no maintenance made it a fine line

 

[Pheasant Surprise]

I think the points been made, but £5k is pretty good really for a 200A supply. The capex for a decent equivalent set would be easily double or triple that, plus the maintenance, housing, fueling etc. cost.

If the connection cost was up around £20k, then personally I'd be looking at a big set but not for the capex quoted. It's a no brainer.

 

[warksfarmer]

Just bringing this thread back to life. We put 3 phase into said shed but now wondering if a generator stacks up better?

basically Red diesel at £1/litre versus current elec prices.

 

[Stuart J]

Just bringing this thread back to life. We put 3 phase into said shed but now wondering if a generator stacks up better?

basically Red diesel at £1/litre versus current elec prices.

Was wondering this too. How efficient is a generator? How many units of electric do you get per litre burned?

 

[warksfarmer]

Was wondering this too. How efficient is a generator? How many units of electric do you get per litre burned?

Not sure where I read it but ……. I’ve seen a quote that says at 72p for Red diesel it works out at 27p/kwh so multiple that up a bit to a £1/litre and it’s still cheaper than 60p/kwh.

 

[Exfarmer]

A decent diesel generator should give a return i energy terms of 30% of the power put in
So one litre will produce about 3.3 Kwh
But don’t blame me if you cannot get this figure.
You will need a generator aimed at the use. So if you have a 20kw 3 phase generator running 2 light bulbs you can expect a notvery efficient conversion

 

[Hilly]

I sometimes run the place on generator due to power cuts , often have measured fuel and fuel alone , no depriciation no service cost no repair cost no inconvenience, its makes the mains look veey cheap and very convenient.

 

[Doing it for the kids]

I’m running 3 x20-40 Kva at the moment, it’s a pain and v expensive.

The power output isn’t very clean and IT kit doesn’t like it. depends what you are using it for but prices can’t stay this high for too long else the country will go bust big time.

All this talk of batteries and panic buying Pv is all well and good and will give a quicker pay back but when prices come back down the quick pay back will be out the window.

We just have to dig in and do our best to use less power this winter I think

 

[jon9000]

Not sure where I read it but ……. I’ve seen a quote that says at 72p for Red diesel it works out at 27p/kwh so multiple that up a bit to a £1/litre and it’s still cheaper than 60p/kwh.

Lee.... you only live once..... do you really want a generator with all the extra hassle compared to mains.....

 

[Fraserb]

We have a big diesel generator that's capable of running the whole farm, it's only used for power cuts as too expensive other wise.

 

[GeoffandLizzy]

Any mileage using a generator to top up batteries. As solar does not add much in the winter months. Could it be combined with wind?