Biogas plant from Omni Heat and Power

mawleymoos

Member
Location
Shropshire
instalation, running costs and reliability are major challenges, with slurry based digesters, as we are working with a relatively large volume of low methane product on dairy farms, that are more comfortable looking after cows as AD plants, compared to industrial sized ones with specialist tech and dedicated labour! if anyone can crack this! and a few have tried and not been able to! there is a fine line, between building too cheap! and it failing! to over spec'ing it and it not being viable! OMNI have built x3 of these and i think ours is probably going the best, although it certainly hasn't been without its challenges! they are still learning no doubt, and thankfully still in business (ours is running nearly 5 years now ) and the way electric price is going, there may be a opportunity for many more if they can overcome these challenges! you mentioned earlier that it is a 50kw engine that your farmer has! so as you say it doesn't leave you much surplus, if you have big pumps! although ours doesn't run for long! is your farmer running on pure cow slurry? or is he adding anything dry? i expect the gas mixer wouldn't do much if too fiberous! am i right in saying you built your own? that would take a bit of doing wouldn't it! and not something we could all do! how is yours going? what are you feeding it? and what output are you getting?what make of engine? are you planning on developing them for others as well? sorry for all the questions! just interested to see success stories as there has been to many failures around!
 

sjt01

Member
Mixed Farmer
Location
North Norfolk
instalation, running costs and reliability are major challenges, with slurry based digesters, as we are working with a relatively large volume of low methane product on dairy farms, that are more comfortable looking after cows as AD plants, compared to industrial sized ones with specialist tech and dedicated labour! if anyone can crack this! and a few have tried and not been able to! there is a fine line, between building too cheap! and it failing! to over spec'ing it and it not being viable! OMNI have built x3 of these and i think ours is probably going the best, although it certainly hasn't been without its challenges! they are still learning no doubt, and thankfully still in business (ours is running nearly 5 years now ) and the way electric price is going, there may be a opportunity for many more if they can overcome these challenges! you mentioned earlier that it is a 50kw engine that your farmer has! so as you say it doesn't leave you much surplus, if you have big pumps! although ours doesn't run for long! is your farmer running on pure cow slurry? or is he adding anything dry? i expect the gas mixer wouldn't do much if too fiberous! am i right in saying you built your own? that would take a bit of doing wouldn't it! and not something we could all do! how is yours going? what are you feeding it? and what output are you getting?what make of engine? are you planning on developing them for others as well? sorry for all the questions! just interested to see success stories as there has been to many failures around!
The installation I am looking at is purely slurry.
Our own digester was originally put in by Greenfinch from Ludlow. Most of their staff went to Marches Biogas when they were bought out by Biogen. I then modified it so it worked reliably on a mixture of strawy slurry, maize silage (the cows have the best out of the clamp), originally chopped beet but now lucerne silage, and whey from our cheesemaking. Apart from the tank and gas holder, I have changed pretty much everything else including the CHP (now a MAN from IET in Austria with 96000 hours on the clock) and the PLC. Hardly a week goes by without some minor improvement to the control system, but the mechanics are pretty much settled now. We have a gas mixing system which is low power and pretty reliable.
If I had not come back to the family farm as a chartered engineer I doubt the system would have worked for more than a year, so if I can help others with my hard earned experience (deep in slurry) then I like to do so.
 

sageb2

Member
Trade
Location
Ireland
I've always been really interested to hear how the omni biogas plants are performing. I'd love to vist one if anyone here has one and doesn't mind me calling and chewing the ear off them for a few hours

I have built a couple of turn-key biogas plants minus the CHP supply. An 80kW plant in Yorkshire running mostly on slurry and a bit of bedding muck back in 2017 and a 250kW plant in Northern Ireland a couple of years ago. The plant in the North runs predominently on slurry and a bit of silage. From my experience slurry only is a doddle. It's when you add solids that things start to get complicated, certainly pushes the capital cost up.

I think I have the slurry only plant design cracked in terms of offering a robust plant for a reasonable price. We're a Permastore Tank and Bauer pump distributor so we get some the main components at a distributors rate so that definitely helps! The CHP is the only thing that i'm struggling to supply competively. I've looked at the Cummins (Chinese) CHP's but haven't seen any in operation. They seem affordable but not sure of the longterm costs.

@mawleymoos would you have a rough cost of running your engine for the past 5 years? Also do you cool the gas and do any desulphurisation?
 

mawleymoos

Member
Location
Shropshire
I've always been really interested to hear how the omni biogas plants are performing. I'd love to vist one if anyone here has one and doesn't mind me calling and chewing the ear off them for a few hours

I have built a couple of turn-key biogas plants minus the CHP supply. An 80kW plant in Yorkshire running mostly on slurry and a bit of bedding muck back in 2017 and a 250kW plant in Northern Ireland a couple of years ago. The plant in the North runs predominently on slurry and a bit of silage. From my experience slurry only is a doddle. It's when you add solids that things start to get complicated, certainly pushes the capital cost up.

I think I have the slurry only plant design cracked in terms of offering a robust plant for a reasonable price. We're a Permastore Tank and Bauer pump distributor so we get some the main components at a distributors rate so that definitely helps! The CHP is the only thing that i'm struggling to supply competively. I've looked at the Cummins (Chinese) CHP's but haven't seen any in operation. They seem affordable but not sure of the longterm costs.

@mawleymoos would you have a rough cost of running your engine for the past 5 years? Also do you cool the gas and do any desulphurisation?
hi sageb2 we are v.pleased with our OMNI plant and glad we didn't go biolectric at the time! we had been looking for a long time, but could never get them to stack up without crops! until we seen the biolectric plants! however they were basically for smaller herds or underutilising slurry! we have ended up with a 80kw OMNI plant and a 1000m3 acconsult concrete tank, probably running at 55/60kwh through the summer when a lot of cattle are out and a bit more in winter! the chinese cummins CHP has been good (giving the stick it gets) and the first engine done 24000 hours i think! before we re-conditioned it! (about 10k) there is a carbon/desulphurisation tank but no gas cooler! one of the bigger issues has been getting parts! although OMNI has managed to get most, they can take a while! (thus we bought plenty of spares and even a complete engine, so as to reduce down time)but other than that, just the usual tear and wear! (altinators, turbo's, water pumps etc etc)
 

Slowcow

Member
hi sageb2 we are v.pleased with our OMNI plant and glad we didn't go biolectric at the time! we had been looking for a long time, but could never get them to stack up without crops! until we seen the biolectric plants! however they were basically for smaller herds or underutilising slurry! we have ended up with a 80kw OMNI plant and a 1000m3 acconsult concrete tank, probably running at 55/60kwh through the summer when a lot of cattle are out and a bit more in winter! the chinese cummins CHP has been good (giving the stick it gets) and the first engine done 24000 hours i think! before we re-conditioned it! (about 10k) there is a carbon/desulphurisation tank but no gas cooler! one of the bigger issues has been getting parts! although OMNI has managed to get most, they can take a while! (thus we bought plenty of spares and even a complete engine, so as to reduce down time)but other than that, just the usual tear and wear! (altinators, turbo's, water pumps etc etc)
How many cows are feeding that?
Thanks
 

mawleymoos

Member
Location
Shropshire
Yes heat is on top of that, and we have approximately 290 cows ayr milking/ predominantly housed /loafing paddocks in the summer! With another 120 dries/youngstock on cubicles in the winter! Retention is probably closer to 30 days in winter and 40-50 in summer! Hence not as big a reduction as expected!
 

Slowcow

Member
Thanks, v interesting, I keep thinking we ought to look into something similar, we're grazing though and try to keep winter as short as possible.
Is it feasible to shut down in the summer or just keep it ticking over with shed muck/bit of grass?
I know it takes a lot of energy to get them up to heat in the first place and have a feeling this could be where it falls down for us!
 

mawleymoos

Member
Location
Shropshire
Thanks, v interesting, I keep thinking we ought to look into something similar, we're grazing though and try to keep winter as short as possible.
Is it feasible to shut down in the summer or just keep it ticking over with shed muck/bit of grass?
I know it takes a lot of energy to get them up to heat in the first place and have a feeling this could be where it falls down for us!
i would expect that slurry only ones wouldn't be viable unless you can harvest enough slurry from cows being in overnight (as we do) to keep it fresh and running! if you have to invest in a macherator pump/dry feeding system plus increase your mixing load! then i doubt you would be able to make it stack up! although others might disagree (especially at current electric costs)
i would love to know if it is viable! it would be good to run at maximum output all year!
 

sjt01

Member
Mixed Farmer
Location
North Norfolk
Update: After badgering Omni for about 3 weeks I have a quote for a new throttle actuator for the CHP. It appears that they are willing to support the farmer, but their response times are terrible, and far too slow if you are running an AD plant, as by the time you have your answer the digester will be dead.
My impression is that they have taken on more work than they have senior staff for, and everyone is stretched to the limit.
 

Exfarmer

Member
Location
Bury St Edmunds
Update: After badgering Omni for about 3 weeks I have a quote for a new throttle actuator for the CHP. It appears that they are willing to support the farmer, but their response times are terrible, and far too slow if you are running an AD plant, as by the time you have your answer the digester will be dead.
My impression is that they have taken on more work than they have senior staff for, and everyone is stretched to the limit.
Problem right across the renewable sector a complete lack of people able to do any form of maintenance
 

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