The Baxi Ecogen micro-CHP boiler

edited 30 November -1 at 1:00AM in LPG, Heating Oil, Solid & Other Fuels
78 replies 87.7K views
j2011j2011 Forumite
238 Posts
Has anyone installed a Baxi Ecogen micro-CHP boiler and are they as efficient as reported?

Also how more expensive are they than normal boilers to buy?


  • PincherPincher
    6.6K Posts
    I have been waiting for pricing as well.
    British Gas is doing them now.
    The problem is, you can't buy it and install it using any RGI. It has to be put in by an MCS certified engineer.

    Generation Tariff 10p per kWh

    [*]: These tariffs are index-linked for inflation. The Energy Regulator Ofgem will publish the updated tariff levels.
    [**]: This tariff is available only for 30,000 micro-CHP

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

    So, assuming the CHP is on for 12 hours a day for 120 cold days, and one hour a day for hot water for 245 days. 12 x 120 + 245 = 1,685 hours. At 10p per kWh, that's £168.50 a year from Feed-In-Tariff.

    So, you get 1,685 kWh of electricity for free, and then you get £168.50 Feed-In-Tariff, reducing over 10 years. Assuming £300 a year for ten years, the benefit is worth £3,000.

    I had to swap the old boiler in March 2010, due to the deadline for the Boiler Scrappage Scheme. I was reading about the CHP, but it wasn't really available. The maximum heat output from the Baxi is 24kW, which is borderline for my house.

    If it's £3,000+VAT, including installation by an MCS, and it qualified for the £400 Boiler Scrappage voucher.
    It would have been like getting a new boiler for free.

    Damn, damn, damn.
  • ollskiollski Forumite
    943 Posts
    Have the exclusive rights to Bg now ended on this one?, I also thought it was mighty expensive??
  • PincherPincher
    6.6K Posts
    I didn't know it was BG exclusive.

    It says £3,000 "Incremental capital cost", whatever that means, on page 19.

    This says Coming Soon, check BHL for availability

    It's just as well it's not available, or ridiculously expensive, because I can't rip out a brand new boiler to swap it in.

    I was keen on it for a blackout scenario, but it probably doesn't work that way. What I want is a CHP that can startup without mains electricity, possibly using a battery backup or a manual ignition.

    During a blackout, I would disconnect the main consumer unit, to isolate the house from the grid. Start the CHP, and run essentials like lights and heating (gas). 1kW should be enough to run the zone valves and circulation pump.
  • edited 12 February 2011 at 7:19PM
    GrahamEGrahamE Forumite
    6 Posts
    edited 12 February 2011 at 7:19PM
    I have just installed a Baxi Ecogen 24 on 2 February. Total installation cost was £5,977. This compares to the quoted cost of installing a standard SEDBUK A condensing boiler of £2900. Part of the higher cost is the Ecogen unit itself which is priced at £3,743 and the cost of electrical installation that you don't have with a standard boiler. So the "incremental capital cost" is the difference between installing a standard condensing boiler and a mCHP unit.

    Based on the results of the 9 days of operation it has generated an average of 8kWh/day of power and reduced normal electricity consumption by 4kWh/day. Based on my marginal electricity costs and the FIT rate of 10p/kWh for generation and 3p/kWh for export (which is assumed to be 50% of the quantity of electricity generated) I'm currently forecasting a total economic benefit of around £35 per month during the winter months. Gas usage is about 10% lower than the previous boiler but that was SEDBUK D rated, and of course is complicated by the external temperatures being different, i.e. warmer weather means lower gas usage.

    So from an economic perspective, and assuming just 6 months of substantial use in winter, that means income/savings of around £210/year, which divided by the incremental capital cost of about £3000, gives a simple yield of 7%. Whether this justifies the investment depends on what your cost of capital is. Taken over the 10 years of the FIT period and assuming a) that energy costs rise by around 10% per year on average, and b) the boiler lasts that long I calculate the nominal Internal Rate of Return at about 2%. Not great, but I'm betting on energy costs rising substantially more than 10% per year over the period.

    As the data improve with time I'll re-post with an update.

    Some other background information : The Ecogen design was developed by British Gas who then sold it to Baxi - part of the condition of sale being that only BG is authorised to install the Ecogen for Baxi. So you get slightly higher installation costs because it's BG rather than your average local heating and plumbing company. However, to get the FIT payment the installer needs to be MCS authorised, and most local companies aren't.
  • gas4yougas4you Forumite
    2.6K Posts
    Hmmm. Jury still out on these.
  • I have been quoted over 8K fully installed. A lot of extra cash over standard condensing boiler for a small saving in electric bill??:(
  • ollskiollski Forumite
    943 Posts
    I know of two which have been removed and replaced by standard condensers as well due to noise.
  • macmanmacman Forumite
    48.7K Posts
    Part of the Furniture 10,000 Posts Name Dropper
    And do you have to get only BG in to service them? For me that would be a big minus point.
    No free lunch, and no free laptop ;)
  • ollskiollski Forumite
    943 Posts
    macman wrote: »
    And do you have to get only BG in to service them? For me that would be a big minus point.

    No there's nothing to service on the stirling engine side.
  • PincherPincher
    6.6K Posts
    The new boiler is a year old, but my plumber says condensing boilers last about ten years, so just in time for when CHP gets to £2,000 per installation. Cross my fingers.
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