Would anyone think it's possible to generate a few kW/h for yourself cheaply

euser1984

Just for myself, to power some equipment. I worked it out roughly to be about 1 euro a kW with green diesel as opposed to the ESB's 17c or so and half price at night.

Thanks.

Red Alert

The only thing I would say is if you are going to try this then don't try and connect it to your house wiring, seriously!

heinbloed

...1 euro a kW....

Not sure if that's per kWh or per kW potential - but

any installer will be happy to sort you out.

Contact an energy advisor.

Bruthal

heinbloed wrote: »

Not sure if that's per kWh or per kW potential - but

any installer will be happy to sort you out.

Contact an energy advisor.

Well it cant really be per kw anyway. Thats not a quantity.

deandean

It's something i certainly looked at allright.

I got an Owl energy monitor a while back and I noticed that there's a 'base load' of about 0.5kW in my house for freezer, etc etc. That's about 700 Euro per anum in ESB cost, or about 1/2 my entire ESB bill!

Now if I had a little generator here that just covered that 'base load', it might be a runner. E.G. micro gas turbine or IC engine Powered off natural gas at 6c per kWH and allow 60% efficiency should give me about 10c per kwH, saving 300 Euro per anum.

To do it right I would need to make the unit a CHP system, so it'd heat water too.

And of course it'd need to be synchronous with the ESB, which costs a bit.

{sigh} so many ideas, so little time:rolleyes:

Red Alert

It wouldn't necessarily need to be synchronous with the ESB. You could have it as an auto-changeover system on specific circuits.

Bruthal

A change over would be more suitable for a backup generator.

For a continous supply to power the `base load` from a small output device, then a grid tie invertor might be the best setup for that. The power supplying device will need to be either DC, or converted to DC with a rectifier first.

dowtcha

deandean wrote: »

It's something i certainly looked at allright.


{sigh} so many ideas, so little time:rolleyes:

I doubt whether its cheaper to generate domestic electricity than mains supplied, in terms of fuel and operating costs / kWhour of electricity generated. End of.
I think any CHP efficiency needs to be looked at interms of electrical and overall efficiency, from additional heat recovery. I amn't aware of any CHP engine with an electrical generating efficiency of over 30%. If heat recovery is maximised then the overall efficiency can rise to 80-85%.
Renewable electrical generation have no input fuel costs, however the likes of wind and solar PV have in common with CHP plants, payback times are subject to economies of scale, and at a domestic scale mains electicity is still cheapest

Micro gas CHP engines do exist, but are expensive, and paybacks are long, and you need a use for heat all year round. Similarly with domestic wind turbines/solar PV panels, paybacks are long even with feed in tariff supports. The proof: how many of these installations do you see around the country. Of course if you are convinced of the economics and wish to be an early adopter, don't let me put you off, but as the saying goes, check twice and cut once, not the other way round

Bruthal

dowtcha wrote: »

I doubt whether its cheaper to generate domestic electricity than mains supplied, in terms of fuel and operating costs / kWhour of electricity generated. End of.

There is something funny in an ironic way about the first 2 and last 2 words in that sentence:pac:

dowtcha

robbie7730 wrote: »

There is something funny in an ironic way about the first 2 and last 2 words in that sentence:pac:

Glad my assertion is proving a source of ironic amusement for you, I am of course, convinced of what I saying, but not so arrogent to believe there may be some Boards member who is in a position to convince me otherwise - over to you mr irony

2011

dowtcha wrote: »

I doubt whether its cheaper to generate domestic electricity than mains supplied, in terms of fuel and operating costs / kWhour of electricity generated. End of.
I think any CHP efficiency needs to be looked at interms of electrical and overall efficiency, from additional heat recovery. I amn't aware of any CHP engine with an electrical generating efficiency of over 30%. If heat recovery is maximised then the overall efficiency can rise to 80-85%.
Renewable electrical generation have no input fuel costs, however the likes of wind and solar PV have in common with CHP plants, payback times are subject to economies of scale, and at a domestic scale mains electicity is still cheapest

Micro gas CHP engines do exist, but are expensive, and paybacks are long, and you need a use for heat all year round. Similarly with domestic wind turbines/solar PV panels, paybacks are long even with feed in tariff supports. The proof: how many of these installations do you see around the country. Of course if you are convinced of the economics and wish to be an early adopter, don't let me put you off, but as the saying goes, check twice and cut once, not the other way round

Good post.

I think deandean (and possibly the OP) needs to look at to being more energy efficient. I think that they will find that this will provide a quicker return on an capital investment than trying to generate electricity.

This can be achieved in a number of ways including better insulation, "smarter" heating controls, more energy efficient appliances and lighting.

LLU

dowtcha wrote: »

Glad my assertion is proving a source of ironic amusement for you, I am of course, convinced of what I saying, but not so arrogent to believe there may be some Boards member who is in a position to convince me otherwise - over to you mr irony

well if you're going to go around using phrases like 'End of.', what do you expect!

same goes for 'As soon as'.

Bruthal

dowtcha wrote: »

Glad my assertion is proving a source of ironic amusement for you, I am of course, convinced of what I saying, but not so arrogent to believe there may be some Boards member who is in a position to convince me otherwise - over to you mr irony

It was a joke, sorry about that, wont happen again.

2011

robbie7730 wrote: »

It was a joke, sorry about that, wont happen again.

Funny guy huh?

I do the jokes around here, OK :D

Bruthal

2011 wrote: »

Funny guy huh?

I do the jokes around here, OK :D

Shut up, we already know your phone cable twisting standards here:D:D:D

deandean

Meanwhile, back at the ranch.... Found It!

I knew I'd seen an affordable, commercially available domestic CHP unit somewhere with a stated payback time of 8-9 years. So not 'end of' dowtcha

Baxi micro ecogen, provides about 11kW heat and 1kW elicktrickery using a Stirling cycle engine. The cost seems to be in the region of 3K Stg.
Shame I bought a new gas boiler last year; otherwise I would get one of these units.

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

Bruthal

A come back 2011, i really was jokin this time:D:D

2011

robbie7730 wrote: »

A come back 2011, i really was jokin this time:D:D

:D

dowtcha

Sorry deandean to rain on your parade, but not so fast. I think your payback times may be pulled from within a UK setting, where there are tariffs for both a) micro generation of every kWh of electricity produced and b) export/spillover of microgenerated electricity via an export meter
Back here at the Irish "ranch" I'm afraid for micro gas CHP generation there is NO payments for either. Also I would be very interested to hear from any RGII contractor to even see if the installation of such a unit is allowed in Ireland? After the RGII, getting the installation cleared by ESB Networks for allowing the Baxi unit to export to the mains, would have to be cleared

Buried deep within the Baxi literature is a key figure : max 1kW of electricity is produced , alongside 6kW of additional heat - A really poor electrical efficiency, something between 10 and 15% !
Have you thought how many hours of the year you can use 6kW of continuous heat generation? I see the heat output can be turned down , but then so does the electrical output

My humble opinion is in an Irish context, the payback would be stretching to 20 plus years, considering the amount of time the heat output could be used across the year - assuming this rules out blasting CHP heat out your rads in the height of summer or when the house is unnoccupied / everyone is asleep ??

Economics aren't everything, but caveat emptor and so on

dowtcha

Just in case ye'all think I'm biased, have a look at the comments on this link, seems like the Baxi micro CHP isn't being welcomed with open arms in the UK

http://www.yougen.co.uk/blog-entry/1464/Long+awaited+Baxi+Ecogen+Micro-CHP+unit+launched/

STG cost of unit seems to vary a bit too ?

dowtcha

Hey, where have all the comedians gone....???

Have been having a scout around boards postings on micro CHP, nothing overly positive to report, however I am wiser, it seems there are 3 micro CHP installations registered in Ireland, and furthermore this link suggests that micro CHP is being backed, I think promoted would be overdoing it, by some of the major gas suppliers

http://www.calorgas.ie/wp-content/uploads/2011/01/EcoGen_A4.pdf

However going back to the OP, micro CHP won't "cheaply" generate a few kWh as things stand

Bruthal

dowtcha wrote: »

Hey, where have all the comedians gone....???

They are gone off to have their sense of humour removed:pac:

dowtcha

robbie7730 wrote: »

They are gone off to have their sense of humour removed:pac:

Shouldn't take long so

Bruthal

Anyway OP, for powering what is likely your computers, there wont be anything easy that can cheaply power them compared to the utility suppliers without a large initial outlay.

A dual tariff meter would reduce the running cost of them anyway, if you have standard tarrif at present, but whether its viable to do this would depend on what the rest of your usage is like, and can some of it be used during the night instead of the day, as daytime units are just over 1 cent dearer, and the standing charge is 13 cent a day more.

Because your computers will be running 24 hours a day, and was it 5kw load?, then it seems likely a dual tariff would be of benefit.

@deandean
If i was in an open area i would look into a small wind turbine option myself for powering the base load as you nicely put it. Id have an interest in doing that myself if i was on an open area.

But any current options have long payback times. Nothing new or complex in that concept. Its all been said before.

LLU

grammatical differences aside, I think dowtcha is on the mark here. unless you're lucky enough to have a millrace in your back garden you're not going to get electricity any cheaper than the grid.

dowtcha

Is it a case of "if it was easy everyone would be at it" , producing a few kWhr of electricity that is ??

Two factors which don't work in favour of microgeneration are a) economies of scale - you hear a lot of talk about microgeneration being more efficient by virtue of eliminating line power losses and generating power where it is going to be used, but any microgeneration installation payback has a lot of ground to make up vs. a conventional power station and b) the same safeguards need to be present for microgeneration vs. a large scale wind turbine, say for example, so for any form of microgeneration it would the case that the invertor with anti islanding controls and one which is G10 compliant will constitute a far greater % of capital costs than the same grid connection controls for a 3MW wind turbine

Bruthal

LLU wrote: »

grammatical differences aside, I think dowtcha is on the mark here. unless you're lucky enough to have a millrace in your back garden you're not going to get electricity any cheaper than the grid.

I dont think it comes as that big a surprise to most, that its more expensive in the short to medium term to generate your own electricity, than to buy from a utility company.

dowtcha obviously thinks he has to convince us of the above, almost common sense fact. But he has provided evidence in his first post that in fact, everyone does know this

dowtcha wrote: »

The proof: how many of these installations do you see around the country.

dowtcha

Anyone interested in reading a bit more on microgenration, there is some intersting posts on this

http://www.boards.ie/vbulletin/showthread.php?p=73907294

Bruthal

dowtcha wrote: »

Is it a case of "if it was easy everyone would be at it" , producing a few kWhr of electricity that is ??

Two factors which don't work in favour of microgeneration are a) economies of scale - you hear a lot of talk about microgeneration being more efficient by virtue of eliminating line power losses and generating power where it is going to be used, but any microgeneration installation payback has a lot of ground to make up vs. a conventional power station and b) the same safeguards need to be present for microgeneration vs. a large scale wind turbine, say for example, so for any form of microgeneration it would the case that the invertor with anti islanding controls and one which is G10 compliant will constitute a far greater % of capital costs than the same grid connection controls for a 3MW wind turbine

The only real factor that works against them is the actual capital outlay, and possibly the suitability of the site.

The fact the invertor in a small setup will be a bigger percentage of the capital cost has little to do with it really, apart from it being part of the cost. If a microgenerator setup was easily affordable for everyone, it wouldnt matter if the invertor was 50% of the cost.

dowtcha

Robbie you are of course correct in saying that if they were affordable then it wouldn't matter if the invertor was 50% of the cost.

However I humbly suggest to you this is a bit like saying "if my auntie had balls then...", so I'm not sure you are making much of a point there

I am merely saying that one of the reasons why microgenration is currently unaffordable is the current cost of invertors and the large % of total installation cost they represent

Bruthal

dowtcha wrote: »

Robbie you are of course correct in saying that if they were affordable then it wouldn't matter if the invertor was 50% of the cost.

However I humbly suggest to you this is a bit like saying "if my auntie had balls then...", so I'm not sure yout making much of a point there

Im surprised the "end of" phrase wasnt used there. Id say the phrase "by your logic" will be along soon:)

I am merely saying that one of the reasons why microgenration is currently unaffordable is the current cost of invertors and the large % of total installation cost they represent

I can see what your thinking, but comparing the individual componets of a 3mw generator in terms of their percentage of total capital, to the same criteria in a generator 1000 times or 3000 times smaller is hardly of much relevance. And even less relevance to your uncle sally there.

dowtcha

Wouldn't say we're going anywhere fast here Robbie, fact is most microgenration is unaffordable in the context of having long paybacks for Ireland at any rate, at the risk of stating the "obvious"