The Baxi Ecogen micro-CHP boiler

jonewer

http://www.baxi.co.uk/products/2137.htm

The Baxi Ecogen micro-CHP boiler produces up to 1kWh of electricity

It produces up to 1kWh? What happens when its produced it? Does it asplode? Does it pack its bags and head off to the costas? Do I have to buy a new one?

Doesnt really fill me with confidence when a company whose business is heating doesnt know what a kWh is!

grumpyoldsteve

jonewer wrote: »

It produces up to 1kWh? What happens when its produced it? Does it asplode? Does it pack its bags and head off to the costas? Do I have to buy a new one?

Doesnt really fill me with confidence when a company whose business is heating doesnt know what a kWh is!

I'm no expert, but to me it obviously depends on what the heat demand of your heating system is at any given time, :think: as electricity is produced as a by product of the primary boiler function to provide hot water, so therefore electricity production will fluctuate accordingly up to the maximum that the Sterling engine can produce i.e. 1kWh, which is presumably when the primary burner is at it's maximum output of 6kWh of hot water heating capacity.
....when I say I'm no expert, I have studied the operation, installation and specification documents available online at Baxi's website, just so I have some idea what British Gas will be quoting me for

GrahamE

I'm responding to several points here:

kW versus kWh on the Baxi website - I guess everyone can make a typo mistake. Send them a note to let them know and they might correct it.

Sterling engine output: the primary burner only runs at 6kW i.e. its maximum output - this produces 1kW of electricity from the Sterling engine. Further heat output comes from the secondary burner (maximum output of 18kW) and this does seem to modulate depending on demand.

Where it can be installed: The unit weighs something like 100kg+, so in order to fit it the installers use a small trolley with a wind-up raising platform, which means they need to have clear access to the wall - so if there are any floor mounted kitchen units these will be in the way.

House size: My house is 5 bedrooms, but that isn't really the relevant figure. What matters is what the heat demand of your house is. When I was researching this back in December 2010 I calculated my heat demand on a room by room basis and came up with a figure of 19kW. The British Gas salesman used a whole house dimensions method and came up with a figure of 18kW. [If you want to do a quick calculation check the sizes and heat outputs of all your radiators and add them together - assuming that they heat the house adequately now it will give a you a reasonable figure for your heat demand]. You should then add on 10% to allow for colder than normal weather and 3kW for heating your hot water.

Noise: There is a slight hum which I don't notice unless I actually listen for it - and it's a lot quieter than the previous boiler. This will really depend on how sensitive you are to background noise.

Solar PV: In July 2011 I installed a roof mounted Solar PV array. My main concern at the time was whether the two sources of electrical power would interfere with each other - they don't. Both work fine together, and are connected into the same mcb on the main distribution board. My rationale for putting in both mCHP and PV was that in summer there's plenty of sunshine but I'm not going to be using the central heating much and in winter there's not much sunshine and I will be using the central heating. Therefore they shouldn't 'cannibalise' output.

Hope this helps.

jonewer

GrahamE wrote: »

kW versus kWh on the Baxi website - I guess everyone can make a typo mistake. Send them a note to let them know and they might correct it.

Pretty major typo. I guess they're lucky that the vast majority of their customer base are scientifically illiterate.

I have no intention of correcting them. I'm not paid to proof read their website.

grumpyoldsteve

jonewer wrote: »

Pretty major typo. I guess they're lucky that the vast majority of their customer base are scientifically illiterate.

lol, I think re-reading my last post I could have been one of those as I am getting confused with it all myself...on the other hand I doubt very much that I will become one of their customers.

Mortgage debt £0...it's all mine :j

Orffyreus

Personally I think that CHP boilers at current prices plus there "incremental costs" are a complete waste of money. Even given the fact that they qualify for the FIT tariff of around 10p per Kwh (index linked of course) does not make them cost effective or advantageous (the reason most people are currently installing this type of technology)
New technology always comes at a price but when MCS installers are quoting £1500-£2000 per installation/day for very simple electrical installations take up and advances of technology will always be slow.
I opted for a new boiler fitted with a flue mounted energy catcher 97% efficient (£1500.00 installed) 5KW log burner Defra approved (£1480.00 installed) 2.45Kw PV system (£7400,00 installed) on 43p tariff. Total £10380 minus a return of minimum £25k so it looks like a winner to me plus I get to save my bit of the planet too.

@ GrahamE

Due respects for your green efforts in adopting all available technology but how on earth do you manage to use 4265kw of electricity a year! Our household comprises of 2 adult, 2 kids, aged 10 and 12 and I work from home during winter and only used 2500kw a year before the panels were fitted!

I think its about time that we all realized (people and government together) that the problem is not the amount of pollution created but the amount of energy consumed.

grumpyoldsteve

Orffyreus wrote: »

I opted for a new boiler fitted with a flue mounted energy catcher 97% efficient (£1500.00 installed)

Presumably you mean a condensing boiler. Can I ask which make/model range you went for and if you got intelligent controls and weather compensation to go with it (up to 12% extra saving on gas when fitted to a condensing boiler)?
Getting my first quote tomorrow and have made have pretty much decided which boiler/control system options I prefer based on research I have done of the various manufacturers offerings (which doesn't now include the Baxi Ecogen) and I reckon I will save at least as much on gas alone than the Baxi would save on gas and electricity - mainly because I don't think our house is suitable, so would not get the best out of the Baxi (which needs to happen to justify it's huge cost).

Re your electricity consumption, are you sure part of your supply is connected to your neighbours house? I sometimes wonder if our neighbors are tapping into our supply with our consumption:( 4 adults, multiple TV/Sky installation, Xbox, computers, dishwasher, washing machine, 2 fridges, freezer etc = lots)

Assuming you have an optimally orientated solar PV installation a good location, then the ridiculously high return on investment from this is one reason why the government are now running around like headless chickens and possibly destroying the solar industry in the process! Fair play to you for getting a low priced installation on the higher FiT.

Orffyreus

Hi Steve, The boiler is indeed a condensing boiler but the energy catcher is basically a heat exchanger that sits on top and preheats the boiler inlet water, there is also a combi store option with a 14 litre hot water storage tank. See ravenheat.co.uk for details.

The CSI 150 model that I purchased comes with a 3 year warranty too, if installed and maintained in accordance with manufacturers guidlines etc. I did get my system at a good price but that is because I have the time to shop around and find the best deal so be prepared to pay up to £2000. I have a wireless digital thermometer and TRV valves on most rads and because I have a log burner to supply most of my heating I expect gas usage to go down from 3 units a day to 3 a week! This will be zero during the summer as I will use the electric shower and take advantage of my free/subsidized electricity.

I have spent quite a lot of money on LED bulbs and use down lighters to illuminate work surfaces. Experience has taught me that the 12volt MR16 led bulbs are much better and brighter than the 240volt GU10 unless you want to spend £30.00 plus on EACH Phillips GU10 bulb, other energy saving come from not leaving chargers plugged in, some will cost you around £10 a year to run! How many do you have that you don't even think about??

Solar installation is not optimal at 135 degrees with 27 degree tilt. Initially we asked a couple of the "fit em free" companies but they said it would not be worth their while because of the orientation so decided to do it ourselves. I agree that the FIT was too high but most people do not realise that the MAIN reason for any Government incentive is to stimulate the economy through sales and job creation, reaching the green energy targets is secondary for them. If the powers that be, pardon the pun, were really interested in renewable energy they could insist that all new builds had a south facing roof and had a mixture of solar PV and solar thermal technology installed.

Unfortunately because of the lack of coherent leadership with regard to renewables we will end up with around 12 nuclear power stations on our little island. At what cost I wonder?

grumpyoldsteve

Thanks Orffyreus for your very informative response. I am happy to say that I am not in a position to need to rush into replacing the boiler, so can shop around too, but hope to have a new one at the latest by next winter so I can start saving (currently I have an old 28 year old original fit boiler which still works fine - but efficient it is not).
I had never seen Ravenheat before, but it seem they only do combi's which may be no good for our situation (or maybe I need to look again at their combistore).

Sounds like you have done your homework on the Electricity energy saving front, and since having solar panels installed myself back in September (also a 2.45 kWp system at the 43p tariff but paid a lot more than you to have it installed - don't ask!! - it is South facing though and performing well, so am pleased with the system), I have become much more energy conscious and am currently going around with one of those plug in monitors as well as the overall energy monitor to establish where the power vampires are. I will be doing a new kitchen in the near future so I will take on board your tips about lighting and also get the remaining old appliances updated to A rated ones.

Orffyreus

Your welcome Steve. Obviously getting a combi will depend on the size of your house, number of radiators, that said there are probably some on the market with much higher outputs and it may be possible to fit the energy catcher to those as it is not just restricted to Ravenheat and I do believe that they have licensed it to other manufacturers, again I would check manufacturers guidelines etc.
You could say that I have done a little bit of homework on energy saving, I am probably bordering on the obsessive side! I am currently turning an old freezer into an air source heat pump for the conservatory and then it will be onto rainwater harvesting as water is now the biggest monthly utility bill.
If you are having a new kitchen you should consider an induction hob as they are very efficient too and you can get a Beko 4 zone hob from BHS direct, delivered for £190. Fit down lighters under kitchen cupboards to illuminate work tops as you will need fewer of them.
Also noticed you had posted about your meter going backwards since having solar installed, mine does too. In fact on one sunny day with 2 computers, the TV and 2 rings of the hob on half power the meter was still going backwards. I suspect it will not be too long before the energy companies will prioritize, those with solar, for replacement meters.