Author Topic: Uk Grid-Tie >> Anyone done it?  (Read 4778 times)


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Uk Grid-Tie >> Anyone done it?
« on: October 17, 2006, 01:43:26 PM »
New here, hello everyone.

Apologies for the 'pop quiz' question - but has anyone managed to grid tie an instalation in the UK yet?

Using the national grid as my battery looks sound, and I was offered a buy back rate of 7.5p a unit last year.
I figure a 10/1 or 12/1 Listeroid running a 5KW genhead on WVO for as many hours in the day as is possible
could make some money and provide me with an interesting hobby.
Or have I just got this plain wrong?



  • grazy dutch in Greece
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Re: Uk Grid-Tie >> Anyone done it?
« Reply #1 on: November 04, 2006, 08:15:37 AM »
I think the silence speaks here. ;)

For running on the grid you need to stay on the 50 Hz perfectly. and there is your problem using a lister.
The listers are to slow in respons to be a grid slave setup.

If you want to sale consider to use a battery charger and grid inverter to do this.
One telephone to your elec. supplier and you will know about the approved models for this.

But this is not a simple setup and unless you are recovering the heat to heat the house and sale your elec. production it will be a expensive hobby.

Greetings from a very wet and cold Greece. >:(
lovson 6/1 DI backup for my new house using solar heating and power plus a 1000W wind generator.


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Re: Uk Grid-Tie >> Anyone done it?
« Reply #2 on: November 04, 2006, 01:08:25 PM »
If you have all the legal and technical hurdles over come, the main item becomes money. What is it going to cost you on fuel and engine service/repair to feed to the grid. I dont know anyone doing it with an engine. But others are doing it with solar and wind. The fuel is free and even that that, payback (if payback interests you) is many many years out.

The cost per kw/h the utility co will pay you is well under the retail price. There is no money to be made unless your big.

Keep you money in your pocket until you are 100% sure.



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Re: Uk Grid-Tie >> Anyone done it?
« Reply #3 on: November 05, 2006, 03:33:38 AM »
in 99.999% of all installations done by individuals the payback just will never come.

even if you have free fuel, the costs of installation, maintenance, labor etc will be doing good to break even within the lifecycle of the equipment.
this is for any scheme that anticipates making a dime in profit.

that being said, a careful setup a case might be made for using the grid as the battery albeit likely an expensive battery.

considering that most batteries are only ~80% efficient average over their lifespan, this provides a bit of offset in favor of the grid battery scheme.

i have done the math many times over the last 10 years and i have come to the following conclusions

1.i would not produce i watt for sale, each watt generated has far more value to me than anyone or any utility would ever pay me for it.

2. incorporate cogeneration into your plan, this is quite frankly the only way you can produce power anywhere near what you will pay a utility for it.

3. conserve, conserve, conserve,,, each watt you can cut out is a watt you do not have to generate, if you do an analisys you will find that it pays huge to conserve

4. schedule your loads, power those heavy loads you can schedule during run time of your system, each watt you can use directly and not convert and store is a large step in the right direction.  scheduling loads can make considerable cuts in the system size requirements. for instance if you do not want to schedule, conserve or plan, you might find you need a 28/2 lister, a huge battery bank, 15kwatt gen head etc just to get by as opposed to a 6/1 or 8/1 smaller battery bank and gen head.

i and others could go on and on, regarding this topic.

if you sit down and do the math, develop the system, and work out the kinks on paper, i think you will find that it will become a very exciting and fun hobby that pays instead of costing you money, unlike most hobbies :)

10 years ago when i started in earnest to lay out and begin my plan i thought i might need 25kwatt generating capacity, after some careful thought, research, planning and conservation, scheduling etc i find i can do as well with well under 5 kwatt of generating capacity. this process of education, research and planning has become quite an exciting hobby all unto it own.

bob g
otherpower.com, microcogen.info, practicalmachinist.com
(useful forums), utterpower.com for all sorts of diy info


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Re: Uk Grid-Tie >> Anyone done it?
« Reply #4 on: November 10, 2006, 02:08:02 PM »
Thanks for the responses guys - much appreciated.

Yes Peterako, I had all but given up on the post and assumed I was way off-track.  Ignoring this possibility I will go on and explain something of what my febrile mind has been working at…..

The background to this was a QED moment I had.  I looked at wind turbines up to 5KW, but they are all very well.  Firstly you need planning permission for your mast, and then you need a certified system of connection primarily a decent inverter.... then you need the wind to blow - and not stop ever!

My logic went like this.... take the electrics (and DC generator) direct from a wind turbine - and strap it to a Lister running mostly WVO.  Connect the DC output to an SMA Windy-Boy inverter and sell power to my util company at 7.9 pence a unit (KWh). [I also get to cancel out most of the power I have to buy at retail price - was £40 last month].

Here are some estimated costs.....v.rough!
SMA WindyBoy Inverter £2000
Listeroid £1250
Engine Shed £500
Electrics £250
Generator £500 [4-5KW]
.....TOTAL £4500+

To recoup this cost on free fuel alone (!!?) I would have to run the genset 24/7 for about 525 days!  Although I have not included money saved on electric bills in this calc.  I had also planned to use the excess heat to run a hot-tub [perhaps this is wasteful  :-\ ]

For the time being I will have to go with you Mobile Bob, I'm going to order some more insulation for the house and get some more low energy light bulbs!!

« Last Edit: November 10, 2006, 02:14:56 PM by oily_rag »


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Re: Uk Grid-Tie >> Anyone done it?
« Reply #5 on: November 10, 2006, 04:19:30 PM »
Hmmm, I was blogging about this very subject last week.

Where I am in the SW UK we have the most expensive mains power.

10.55 pence per kWh is the cheapest I can buy it.

I have a original working start-o-matic, it will burn a gallon every 4 to 5 hours at full load, eg 2.5 kW

4.5 hours per gallon (imperial) = 1 hour per litre.

so litre price of fuel / 2.5 = cost per kWh in fuel alone.

BTW, I am not going anywhere near the 24/7 availability of grid power vs genny power.

pump diesel is 90 pence per litre, so 90 / 2.5 = 36 pence per kWh

red diesel is 45 p a litre, so brings it down to 18 pence per kWh, in line with most electricity retailers tariff for the first 10 kWh etc

10.55 pence (inc VAT) that I pay per kWh x 2.5 = 26.375, so unless my fuel is less than 25 p per litre, even leaving out genny maintenance, I'm losing money.

If you think you can turn even free chip oil into decent fuel for less than 20p a litre you are lying and not including the cost of collecting it, your labour, consumable, energy used, etc etc etc.


Wanna know where it really falls down?

This numbers above are based on running the genny at peak efficiency, I use about 13 kWh per day here, so that means running at peak efficiency and 100% output for 6 hours and charging battery banks and inverters which then provide me with 24/7 power.

Minimum £1500 for decent battery bank and inverter and charger, more like £2500 to do it properly so I use house power exactly as I do now, like I can turn on anything I want when I want for as long as I want.

Even if my fuel is totally free, my genny miraculously never needs any maintenance, I still need 5 to 6 years to show an ROI on capital costs of the battery bank and inverter alone, add genny, battery maintenance, etc make it 8 to 10 years.


Wanna know wny else it ain't even a dream?

I can buy economy 7 power from the same company for 4.5 pence per kWh, and charge my battery bank that way, that leaves 12 pence for every litre of fuel used, to cover fuel, making fuel, maintenance and materials, my time and labour, etc etc etc.

Can't be done.



IF you can get 7.9 pence per kWh from the grid, and you can buy at 4.5 pence per kWh, then you have a margin of 3.4 pence per kWh, call it 1.4 by the time you lose efficiency in the charge / discharge cycle, so you have 1.4 pence per kWh left to repay the capital investment, say £2,500, and show a profit, so you have a max of about 30 kWh per day available to you, so 30 x 1.4 pence = 42 pence per day,  150 pounds a year, 16 and a bit years to show a profit, just about in time to replace all your capital equipment.


Oh, but I am cogenerating so I get all that HEAT argument comes next.

I'll be generous, for every 10 kWh or usable elecricity you generate, you can reclaim another 10 kWh of useful heat, and I am being really, really, really generous, and not going anywhere near mentioning that the equipment to do this just quadruples the capital cost and ongoing maintenance of your genset.

I use 13 kWh per day of electric, so lets say I can also get 13 kWh per day or useful heat energy.

Like I said, LOTS of capital intensive ancilliary equipment and ongoing maintenance to do that, and at 2.5 pence inc VAT which is what I buy mains gas for I'm saving a whopping 2.5 x 13 = 32.5 pence per day, or 120 quid a year.


shoot the messenger if you like, but run the math, there is absolutely no way to gen/cogen/trigen and do it for less per kWh than the grid, less capital than the grid, less maintenance than the grid, less time than the grid, less enviornmental impact than the grid.

as long as you have a hole in your ass you will not beat the grid on cost or enviornmental issues, simply because of economies of scale.

if you wanna do it because you live 30 miles from the nearest pylon great

if you wanna do it because you just wanna do it for kicks great

Original Lister CS 6/1 Start-o-matic 2.5 Kw (radiator conversion)
3Kw 130 VDC Dynamo to be added. (compressor + hyd pump)
Original Lister D, megasquirt multifuel project, compressor and truck alternator.
Current status - project / standby, Fuel, good old pump diesel.


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Re: Uk Grid-Tie >> Anyone done it?
« Reply #6 on: November 10, 2006, 05:57:12 PM »
I bought a SOM and have 100 gallons of reserve fuel - free used hydrulic fluid - and 20 gallons of Diesel

I am ready for the next 1 day outage - happens a lot in the Ottawa area in the wnter - and the next 23 day outage from an ice storm - happends every 5 -6 years.

The SOM is about 75% back together and ready to work when called.
There is plenty of room for all of Gods creatures... right next to the mashed potatoes...


  • grazy dutch in Greece
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Re: Uk Grid-Tie >> Anyone done it?
« Reply #7 on: November 10, 2006, 07:28:13 PM »
Or you stop buying your power.  ;D

I am building my new house on the moment here in Greece. In order to have power i need 22 wooden pilars a 500 euro. that is 11.000 plus a 2000 for the application athother 500 for the drawings. that is a 13.500 euro to have power at home expensive and a ferry bad one.

So i am using a 1000W windgenerator 200 watt solar panels 2000 AH 48V ( 24 x 2V ) solar battery one 8 KW inverter battery charger.
And if i need to  charge extra i use the lister 6/1, but my battery setup is for 5 days normal house use.

a and this setup cost me 14.650 euro so for a 1150 euro i have power for my house free heat in the winter a and the motor oil and hydr. oil is free.

But oke that counts for me.
lovson 6/1 DI backup for my new house using solar heating and power plus a 1000W wind generator.