Anyone got a flow boiler or similar

evomatt

http://www.theguardian.com/money/2015/jan/17/new-boiler-generates-electricity

Sounds a great idea does anyone have any experience with these?

zeupater

evomatt wrote: »

http://www.theguardian.com/money/2015/jan/17/new-boiler-generates-electricity

Sounds a great idea does anyone have any experience with these?

Hi

So, if you use considerably more energy than average (~66%), pay £1200 up front (replacement standard boiler should be available for ~£2k installed), receive nothing for 5 years, then get your original £1200 back over the next 5 you might just about break even within the lifespan of the unit, add in any repairs on the new technology (homeowner out of pocket responsibility after warranty up to year 5, then from their 50% share of FiT income after that) and you'll just push the B/E point out further.... change any of the variables in an unfavourable way and it looks to be a pretty poor deal (as described in the article) ...

I've not looked at the technology of this particular offering too deeply, but it looks like heat is used to run a scroll shaped 'propeller' which runs a small generator, effectively a refrigeration scroll compressor in reverse - as such it's probably a better design concept than a typical 'sterling engine' design utilising boiler heat for generation but there's still a considerable mechanical aspect to the offering, with all of the wear & tear associated with moving components ...

My thoughts? .... the scheme operators and finance company seem to be loading all of the benefits in their favour and offloading a disproportionate level of risk onto the homeowner - as such it's a pretty similar concept to many of the high cost, package financed deals on solar pv which have been reported on various threads recently ....

HTH
Z

Sterlingtimes

zeupater wrote: »

My thoughts? .... the scheme operators and finance company seem to be loading all of the benefits in their favour and offloading a disproportionate level of risk onto the home owner - as such it's a pretty similar concept to many of the high cost, package financed deals on solar pv which have been reported on various threads recently ....
Z

I almost agree. You have just missed out the fact in the comparison that the purchaser of the alternative system has made an outlay investment of £2,000. Consequently, after 10 years all being well the Flow purchaser could be £2,000 better off. But I firmly agree that it is a huge risk relative to the return: the purchaser could be left with heavy repair costs or if the venture fails a boiler that is totally unserviceable. The front-end incentives are not sufficient. I might bite if Flow should provide a 10 year on demand bank bond (to cover boiler replacement) as an expression of their confidence in the system.

What will be the FIT payment next year for Flow boilers? Do they disappear like solar?

zeupater

Sterlingtimes wrote: »

I almost agree. You have just missed out the fact in the comparison that the purchaser of the alternative system has made an outlay investment of £2,000. Consequently, after 10 years all being well the Flow purchaser could be £2,000 better off. But I firmly agree that it is a huge risk relative to the return: the purchaser could be left with heavy repair costs or if the venture fails a boiler that is totally unserviceable. The front-end incentives are not sufficient. I might bite if Flow should provide a 10 year on demand bank bond (to cover boiler replacement) as an expression of their confidence in the system.

What will be the FIT payment next year for Flow boilers? Do they disappear like solar?

Hi

The main issue is that the figures gave an initial distortion ... £2000 is way over average for dual fuel supply in the UK. If you were in a high heat requirement property the figures stack-up better, but then again it would simply be better to insulate, insulate, insulate - then insulate more ....

What really needs to be taken into account is that the unit generates electricity at a maximum of 1000W (http://www.flowenergy.uk.com/flow-boiler-tech-zone/tech-spec/) so assuming straight line generation to modulation you'd expect ~400W(7/18), subtract self consumption and you get 200W (400-200) useable, therefore earning £500/year (from FiTs) would need the boiler to generate 3776kWh/year(500/0.1324) which at modulated generation would take 18880 hours (3776/0.2), that's somewhere around 51 hours/day (18880/365) ... see the potential problem yet ? .... now, to run the boiler at minimum modulated output (~7kW) all year in order to maximise FiT income you'll need to be meeting a household heat demand of around 61000kWh/year (7x24x365) ... at 4p/kWh for the gas that would cost around £2650 (61000*0.04/0.92) which is way more than what has been claimed .... the technical issue here is what you would be doing with 168kWh/day (7x24) of heat, costing around £7.30 (168*0.04/0.92), in the summer months in order to generate 4.8kWh (0.2*24) of electricity, earning around 63p (4.8*0.1324) in FiTs ...

Odd, the arithmetic seems to be a little shaky somewhere - earning £500/year? ... split 50:50 after year 5 ? ... on a dual fuel spend of £2000/year ? - now, exactly how does that work then when running the unit 24Hrs/day all year at 200W generates a maximum of 1752kWh (24*365*0.2) valued at £232 (1752*0.1324) in FiT and, being extremely generous and assuming absolutely no export and a really good energy deal, saving around £245 (1752*0.14) in electricity - so £477 (232+245) total income/saving ...

It just doesn't make sense to spend pound on gas in the summer just to save pennies on electricity imports and provide a FiT income of a few pennies more, but without doing this you can't get anywhere near the mentioned £500/year .... the details and claims of the article/offering completely fails the test of logical scrutiny ....

Cough ....

HTH
Z

popgoestheweasel

Well there is a lot of mis-information on here, but I believe some chuches may still be open. This is a British company which changes the game on energy perception. The A rated system boiler has been fully tested in the factory and in test homes. You cannot go and just buy one of these - you have to be selected (you need to have a past usage of approximately 18000 kwh a year, if you do not - forget this Flow boiler they will not sell you one - whoever you are.. Once you have qualified, it does not matter what you usage gas or electricity is over the five years. Flow will contractually guarantee you an £80 a month rebate on your energy bill for five years amounting to £4800 - you can see it as a credit on your energy bill ,and REPEAT: your usage does not factor in at all. You can buy the boiler outright or on finance. Outright it costs you £3675 + fitting £1800 (guide could be £1200 if simple adaptation) = £5475. Now if you deduct your received credit of £4800 over five years, the cost to you after that five years is £675. You state the new technology (the scroll generator) is not guaranteed but it is for the first five years and if you continue your energy contract for a further five years you get a 10 year guarantee. If you continue your energy provision with Flow you will share the FITS payments with them and halve the profit of the freely created electricity -50/50 with Flow. The second five year income from half the FITS payments and profit from half the electricity production could potentially be as high as £2400, but could be somewhat less or quite a lot less - it will depend on your general usage and how you use 1/2 the free electricity saving/income you get.The electricity created is best used at the time - you will save (current rate under 11p a unit ) If you export it to the grid you will receive a little over 4p a unit. With the introduction of smart meters we can expect the grids to pay more for exported electricity at peak times and the Flow boiler which is smart - will make use of this for your extra profit. I am going for it, for one property I own, but obviously I will have to qualify. I am also interested in the combi version coming out the first quarter of 2017. I think the deal stacks up - but that is the guts of it. The ordinary functioning boiler (minus scroll) is guaranteed for two years only - but with all the savings plus the fact I have faith in the company, just a relative risk to me. It is only the second five years where your usage influences the profit you make(I have stated that 3 times .

Smart meters are planned to be fully installed by 2020 so the government tells us, and I think exporting profits will very likely increase when this happens.The boiler's launch is planned to take place before the end of this year, so anyone wanting one will have to wait.

All in my honest opinion and it is a little complex, but once understood simple, and I hope that helps you to make an informed choice.

zeupater

How relevant .... read this on BBC teletext last night ...

"Adults who lack basic science and maths skills risk being "bamboozled" and making bad decisions, according to a leading scientist. "

( http://www.bbc.co.uk/news/education-34144310 )

zeupater

Hey, don't get me wrong ... I think that the system's great for what it does .... but that's the thing, what does it do ??

Right, unless there's been a major scientific breakthrough which rewrites all accepted theories in conservation of energy, the electricity generated is actually consuming power from somewhere. There are essentially two ways of looking at this, firstly the unit is a standard GCH boiler with a parasitic-load generator. or a low efficiency generator with efficient heat recovery - whichever doesn't matter as long as it's accepted that it's a combined heat & power unit. There's the crux, it's CHP which effectively means that you only get power when the boiler is providing heat moreover, unless the heat can be utilised the system is unbelievably inefficient, costing much more in gas to generate than the added value of the electricity provides.

I think that the above post sums it up completely ... "The second five year income from half the FITS payments and profit from half the electricity production could potentially be as high as £2400, but could be somewhat less or quite a lot less - it will depend on your general usage and how you use 1/2 the free electricity saving/income you get" ... what does that mean in the real world ... well, in a nutshell, if your heat demand is high enough to run the boiler 24x7x365 in a fully modulated mode then maybe, just maybe it's possible .... however, who does that ?

Okay, so real world .... it's a <18kW boiler, so not particularly suited for medium to large properties where ~30kW+ units are required to meet standard heating patterns/provisions. Small properties are unlikely to have a heat requirement sufficient to warrant running the boiler continuously for long periods, even in the winter - if it is then there's a strong case for insulation as previously raised. So, what does this mean ? ... well, it looks like under-sizing the boiler is a deliberate ploy to encourage longer daily heat-provision periods to make use of the generating capacity .... right, that changes the way that most would plan to use their heating (short blast in the morning and a few hours in the evening), but that's not too bad, as long as the customer knows - we've all seen reports from members of this forum trying to use heat-pumps as they would GCH ...

Okay, you have to be selected and have a heat demand of >18000kWh/year .... so, let's take summer DHW away (say 750kWh?) and say that the heating season is ~183 days, so that gives a daily winter demand of 94kWh((18000-750)/183) which, if fully modulated that's 13hours of use (94/7) and at full power, just over 5Hrs (94/18) .... in the summer the DHW demand is satisfied in about 1/2Hr (750/183/7) or less, therefore very little generation unless energy (heat) is deliberately wasted ....

Heating in the early evening on dark winter months, the system probably fits well with the normal peak electricity times, but that's not what's being pushed ....

HTH
Z

topicalcat

Interesting stuff from popgoestheweasel and zeupater. As with solar PV the benefit of the feed in tarriff and also being able to reduce home energy consumption are very important. The fear of progress and not understanding science (or finance) costs people dear. So far, after 4 years I have earned over £6,000 in FITs and saved over a £1,000 on my electricity bill, substantially paying off the initial cost. But there are millions of people too scared to commit to even that simple technology and the financial alchemy which makes it work. I understand then why it will only be the brave and those who do their research who will take up this new technology.
Some facts, Flow Energy entered the top ten list of best energy suppliers from nowhere in this years Which energy survey. If you stick with them for 10 years energy supply you get a ten year warranty on the clever bit. So IF the basic boiler is of good quality and reliable then this will work. Particularly since the government are still failing to build enough new power stations to see us through the forthcoming winters. OK each flow boiler will not produce 1kw all the time so lets go with the 400 - 500w average when modulating, that is still enough to power all the lights in my house plus the TV and computer Unlike solar, a Mchp boiler will tend to be generating more electricity during cold periods when we are at home during the winter when we ramp up the heating. This could reduce the very real possibility of the lights going out when peak winter electricity generation falls short of demand. I look forward to the actual launch of the boiler though my gas consumption will probably not be enough - I have a wood burning stove with backboiler. But a combi boiler version next year might fit the bill for me. By then the product will be out there and working so that realworld evulations can be made as to whether the boiler can turn in a payback period of less than 10 years. In my books if it can do that it is worth buying. I did once consider the Baxi Ecogen but the pay back period was going to be 15 years! Ie longer than the lifespan of the boiler and longer than the 10 year period for FITS. So i wish Flow well, I really like the idea. They are certainly a good company to deal with as my energy supplier

zeupater

topicalcat wrote: »

Interesting stuff from popgoestheweasel and zeupater. As with solar PV the benefit of the feed in tarriff and also being able to reduce home energy consumption are very important. The fear of progress and not understanding science (or finance) costs people dear. So far, after 4 years I have earned over £6,000 in FITs and saved over a £1,000 on my electricity bill, substantially paying off the initial cost. But there are millions of people too scared to commit to even that simple technology and the financial alchemy which makes it work. I understand then why it will only be the brave and those who do their research who will take up this new technology.
Some facts, Flow Energy entered the top ten list of best energy suppliers from nowhere in this years Which energy survey. If you stick with them for 10 years energy supply you get a ten year warranty on the clever bit. So IF the basic boiler is of good quality and reliable then this will work. Particularly since the government are still failing to build enough new power stations to see us through the forthcoming winters. OK each flow boiler will not produce 1kw all the time so lets go with the 400 - 500w average when modulating, that is still enough to power all the lights in my house plus the TV and computer Unlike solar, a Mchp boiler will tend to be generating more electricity during cold periods when we are at home during the winter when we ramp up the heating. This could reduce the very real possibility of the lights going out when peak winter electricity generation falls short of demand. I look forward to the actual launch of the boiler though my gas consumption will probably not be enough - I have a wood burning stove with backboiler. But a combi boiler version next year might fit the bill for me. By then the product will be out there and working so that realworld evulations can be made as to whether the boiler can turn in a payback period of less than 10 years. In my books if it can do that it is worth buying. I did once consider the Baxi Ecogen but the pay back period was going to be 15 years! Ie longer than the lifespan of the boiler and longer than the 10 year period for FITS. So i wish Flow well, I really like the idea. They are certainly a good company to deal with as my energy supplier

Hi

I'm extremely sceptical about any claims made for new technologies with so little supporting data. The majority of our own heat provision is also from log-burning, DHW being mainly from solar thermal and whatever heat is provided, it's kept in as long as possible through masses of insulation (far above building regs) ... consequentially the GCH gets very little use, but when it is used, after reaching operating temperatures, the boiler spends most of it's operation time fully modulated ... stir in solar gain, low-energy everything and pv and you'll appreciate that we're not anti-renewables in any way, as such my concerns are more related to the claims and package offerings than the technology itself ... oh, then there's the ticket price, which for a standard £600 boiler with a few hundred pounds (?) worth bolt-on parts borrowed from the refrigeration sector does seem to be a little ... (cough) ... steep.

What is really needed is access to a published technical data reference showing generating performance curves related to boiler modulated output, without that I'd be very reticent to believe that generation has anything other than a basic straight-line correlation to modulated output and would have a net benefit for the majority of operating time of more than 200W ... from the available description I don't even know whether the boiler is of standard or system design, so maybe the published 200W unit load doesn't even include ~100W for the CH pump which raises further questions ....

Too many questions arising from too many claims based on so little information - does this really fill anyone with a warm glow of confidence? ..... From experience, an offering which looks to be over-complicated must have reason for having been made that way, the golden rule should be KISS so, if not, why not ? ...

HTH
Z

topicalcat

Forums like this are designed for healthy sceptiscism, it is no bad thing. When the boiler is launched and there are independant reviews on it we will know for a start how well it is built and whether it does what is claimed on the tin. The £600 you quote for a boiler would only buy a bottom of the range model, i get the impresion that this is better than that. I would prefer therefore to see what this new boiler should be benchmarked against. If it is a Volvo quality boiler it should not be compared against a Fiat Punto. It will be more complicated than an ordinary boiler because it will do more. If that works out then fine. We would still be driving around in Morris Minors if we really wanted to keep cars simple. I for one enjoy a heater, servo , disc brakes, a radio ad infinitum. So whilst I appreciate the logic of KISS sometimes we need to push the boat out a bit.

It a fact that good as solar PV is and I love it, it is no use when it gets dark or during the short days of winter. Therefore a boiler which can generate electricity in the depths of winter when it is working hardest must makes sense. For me this is an accounting exercise, if it can be demonstrated that it will cost me less over 10 years than a conventional boiler I will have one. I need a new CH boiler and will make a decision when it is launched and we get independant research from the likes of Which magazine and others who have no axe to grind, or from reliable people in the trade who fit them.
Nothing new would ever get to market if we are all overly sceptical. Healthy sceptisism combined with a little vision to the future is called for here. I dare say that once launched a lot of the technical stuff will be available. Some of this will be confidential pre launch.

ed110220

topicalcat wrote: »

Forums like this are designed for healthy sceptiscism, it is no bad thing. When the boiler is launched and there are independant reviews on it we will know for a start how well it is built and whether it does what is claimed on the tin. The £600 you quote for a boiler would only buy a bottom of the range model, i get the impresion that this is better than that. I would prefer therefore to see what this new boiler should be benchmarked against. If it is a Volvo quality boiler it should not be compared against a Fiat Punto. It will be more complicated than an ordinary boiler because it will do more. If that works out then fine. We would still be driving around in Morris Minors if we really wanted to keep cars simple. I for one enjoy a heater, servo , disc brakes, a radio ad infinitum. So whilst I appreciate the logic of KISS sometimes we need to push the boat out a bit.

It a fact that good as solar PV is and I love it, it is no use when it gets dark or during the short days of winter. Therefore a boiler which can generate electricity in the depths of winter when it is working hardest must makes sense. For me this is an accounting exercise, if it can be demonstrated that it will cost me less over 10 years than a conventional boiler I will have one. I need a new CH boiler and will make a decision when it is launched and we get independant research from the likes of Which magazine and others who have no axe to grind, or from reliable people in the trade who fit them.
Nothing new would ever get to market if we are all overly sceptical. Healthy sceptisism combined with a little vision to the future is called for here. I dare say that once launched a lot of the technical stuff will be available. Some of this will be confidential pre launch.

But I think Zeupater has convincingly shown that in order to generate reasonable amounts of electricity you'd have to burn vast quantities of gas and therefore have an unusually high heating demand, something more like a small industrial process than a domestic heating system. If your house was such a thermal disaster zone, it would probably be better from an economic and environmental point of view to upgrade its insulation.

For comparison our part upgraded 3 bedroom semi gets through less than 9000 kWh of gas for space heating per year.

Ed