Navitron Renewable Energy and Sustainability Forum

CHP (combined heat and power) => External Combustion (Stirling engines / hot air engines / steam engines) => Topic started by: Rhodrons on July 20, 2012, 09:35:23 PM



Title: Baxi ECOGEN - How many of us have them?
Post by: Rhodrons on July 20, 2012, 09:35:23 PM
I recently posted a query about the efficiency of my Baxi Ecogen boiler. Although the post has been viewed many times, nobody actual posted a reply. This set me wondering how many of us have actually taken the plunge and installed one of these beasts. Looking around on the web I can find references to Housing Associations and Local Authorities "spending other people's money" to install these units while upgrading properties as part of green initiatives but I do not see many posts or reports from individuals who have them. I suppose that the incremental costs of the Baxi Ecogen compared to other high efficiency boilers will put most people off but those of us who have them will each have our own reasons for buying them. I'll post my reason and then sit back and wait to see if anyone else shares their reasons - or I am the only owner!

My 25 year old Baxi boiler was like a member of the family. The beauty of its G-rated efficiency meant that it kept my kitchen warm and also dried sports gear, rugby boots and washing quickly. We are just about to refit our 20 year old kitchen and the kids are now flying the nest so I thought it a good time to move to an A-rated boiler. I have followed the Whispergen boiler story over the last few years and being a mechanical engineer involved in R+D at work felt it would be "fun" to try an mCHP boiler. The Baxi ECOGEN ticked all the boxes except for the cost but I run an old car and don't have many nasty expensive habits so this was my indulgence!


Title: Re: Baxi ECOGEN - How many of us have them?
Post by: Other-Power on July 20, 2012, 10:17:00 PM
In all my poking around working with micro generation, what for eight years now, I have only had one customer who had one, his is on LPG and was the first one installed in a private residentail property.

To be honest, he has to much money and he would by de-hidrated water if it was 'in'

He does see a bit back from the FIT but not that much.

I think these things are good but the price is putting people off.

without a heat meter one will never know how damn these things are in real life.

Cheers

Jon


Title: Re: Baxi ECOGEN - How many of us have them?
Post by: martin on July 20, 2012, 10:18:52 PM
Perhaps you're the only person to have actually tracked down a fabled unicorn and installed it! There's been lots of trumpetings about the things for years, I'm reserving judgement on them, but am somewhat doubtful of their "green" credentials..... whistle


Title: Re: Baxi ECOGEN - How many of us have them?
Post by: Ivan on July 21, 2012, 01:49:12 AM
I think they have about 20% efficiency, but the engine is only ~1kW - so you really want to use the boiler at low output for long periods of time, rather than at a normal sort out output level. Bear in mind you have to wait 3minutes after the voltage has risen before you can legitimately connect to the grid and start using/exporting that power. If your boiler cycles every 10minutes, you'll lose 30% of your potential electricity. If it cycles every 5minutes, it's 60% loss, and every 3minutes....I'll leave you to work out that one. The secret to these boilers is to install them correctly - and I wonder how often they are.

Have you checked how often your boiler cycles? Probably the best way to install these is with a large (c. 2000litre) heatstore tank, but that takes up a lot of room in an average house.

Are we allowed to know what the installed cost was?


Title: Re: Baxi ECOGEN - How many of us have them?
Post by: BruceB on July 21, 2012, 08:29:44 AM
Bear in mind you have to wait 3minutes after the voltage has risen before you can legitimately connect to the grid and start using/exporting that power.

I do not believe that is right.  The 3 minutes applies under after there has been a grid failure.  I do not believe there is a limit when the generator starts up with a satisfactory grid voltage in place.  When you switch an inverter dc on, it does not wait 3 minutes, the relays normally start clicking within seconds after it has been through its self test regime.


Title: Re: Baxi ECOGEN - How many of us have them?
Post by: Rhodrons on July 22, 2012, 12:23:34 PM
After a power cut or turning the Ecogen on at the isolator, the boiler goes through a series of self-diagnosis and health checks before it even lights up. The last of these is a "de-aeration function" which takes several minutes and seems to use the pumps to vent any air in the boiler system prior to start up of the burners. Once the primary (6kW) burner fires then there is a 30 second pause befor ethe Stirling engine hot end gets up to generating temperature. This series of checks and start-up functions mean that the 3-minute rule is accomodated by default after a power cut ends.


Title: Re: Baxi ECOGEN - How many of us have them?
Post by: Ivan on July 25, 2012, 01:03:28 AM
Almost all renewable generation equipment goes into sleep mode when no power is being generated. This is to reduce parasitic losses. Indeed, if the generator continues to monitor the grid permanmently, then it can reconnect at any time, but the energy cost of doing so would make quite a significant reduction in the net generated output - which is why systems normally go into sleep mode. As I haven't got a Baxi stirling engined boiler, I haven't checked, but I'd be surprised if it did monitor the grid 24/7, 365days - in which case it may well have a net negative benefit!


Title: Re: Baxi ECOGEN - How many of us have them?
Post by: Other-Power on August 04, 2012, 10:16:20 PM
Almost all renewable generation equipment goes into sleep mode when no power is being generated. This is to reduce parasitic losses. Indeed, if the generator continues to monitor the grid permanmently, then it can reconnect at any time, but the energy cost of doing so would make quite a significant reduction in the net generated output - which is why systems normally go into sleep mode. As I haven't got a Baxi stirling engined boiler, I haven't checked, but I'd be surprised if it did monitor the grid 24/7, 365days - in which case it may well have a net negative benefit!

Thats not the case, a well designed inverter can be connected without delivering power or how else would wind turbine grid tie inverters stay connected as the wind comes in and out at cut in wind speeds?

The Eco Gen I saw, connected and staied connected.

I may look to make a video of this thing starting up and running.

Cheers

Jon


Title: Re: Baxi ECOGEN - How many of us have them?
Post by: baker on August 05, 2012, 12:21:08 PM

Hi most grid tie inverters will go to sleep in  3 minutes
under the upv start voltage power one < 50V
SMA   2500 <   200 vdc
and uk grid guard reconnection time out   is 180 sec /3 minutes
to reconnect
baker


Title: Re: Baxi ECOGEN - How many of us have them?
Post by: Other-Power on August 14, 2012, 04:28:24 PM

Hi most grid tie inverters will go to sleep in  3 minutes


This is ajustable on the SMA with a grid gaurd code, from what I remeber, it dosnt change the settings to G83(trimmed) ie outside of standard G83.

Cheers

Jon


Title: Re: Baxi ECOGEN - How many of us have them?
Post by: Stochengberge on August 14, 2012, 08:56:44 PM
Rhodrons,

As is often the way with Forums, your initial question has been lost whilst in a debate about the minutia somewhere.

It seems that since you started this thread nearly a month ago, there has only been one person who has direct experience of them. The trouble is that it appears to only be Housing Associations and the like installing them (and probably only to boost their "green credentials"). Without wishing to sound rude, the end users generally won't be the sort of people who will be partaking in a Renewables Forum.

I was looking into the Bluegen system for my brother, but the maths just didn't stack up.

Good luck,

Dave.


Title: Re: Baxi ECOGEN - How many of us have them?
Post by: Roger111 on January 19, 2013, 12:12:47 AM
I to have a Baxi Ecogen, cost around 5500 installed, done 18months ago, getting an income around 100 first year and by manipulating on off times hope to achieve 50% increase. If you add in savings from boiler and reduced electric bill might be worth 350 a year total at best. So if 25 year life it would pay for itself, but then home care costs run out at 200 a year so not such a good deal
 wackoold


Title: Re: Baxi ECOGEN - How many of us have them?
Post by: charlieb on January 23, 2013, 10:57:27 AM
Worth it for the satisfaction though Roger111??  (Solar heated baths, for example, make evacuated tubes 100% worthwhile imo. I'm not that bothered by the economics).

(I couldn't resist looking at the economics though!   5500 is maybe 3500 additional cost compared to a heat-only boiler.  So if you do get 350 income/saving per year it looks like a 10 year simple payback, not 25.   Admitted, including maintenance stimies that, but you would have some maintenance costs on a heat only boiler).


Title: Re: Baxi ECOGEN - How many of us have them?
Post by: Clive1471 on November 01, 2018, 06:52:32 PM
We have one in Oxfordshire - alas Baxi have pulled support for if after the government decided to waste shed loads of our cash on an idiot atomic power station project rather than support this marvellous invention. We run ours nearly all the time in winter. As support is ending, check out my Baxi Ecogen support group on Facebook :) 7


Title: Re: Baxi ECOGEN - How many of us have them?
Post by: linesrg on November 02, 2018, 10:57:37 AM
Good Morning All,

As I understand it the Baxi Ecogen doesn't qualify for any RHI payments? Savings gained from installing would be determined by any increased efficiency over the device it was replacing coupled with any electrickery generated?

I suspect such a 'complicated' device might have increased maintenance costs over its life time?

I recall I did look at the device briefly when considering a replacement for our old LPG condensing boiler but ultimately dismissed it as not being an optimal solution for our location.

Regards

Richard


Title: Re: Baxi ECOGEN - How many of us have them?
Post by: dan_b on November 02, 2018, 11:08:06 AM
Then of course there was the Flow mCHP Boiler which was developed, soft-launched, and then died a death due to increased manufacturing cost after the pound crashed, and at the same time Govt slashed FiT rates for mCHP AND the VAT rate was increased from 5 to 20%.   I was very close to getting one but ended up needing to spend the money elsewhere and then it was gone.