Montrose CHP - up and running

[jotec]

The amount generated yesterday according to the inverter readouts was 18kwh. And no I did read it from both drums as it is done by measurement from the top. I will do it again when I next fill up and do it by refilling with a known quantity. I am still well pleased though. Yes £30 worth of power and the ROCs reclaimed plus the heat and may be RHI next year?

Regarding freezers I was not thinking of running from a genny rather direct drive from the diesel. If as you say the initial load is large then start on mains and turn the motor off and run direct from a diesel/ Would need clutches and one way drives but could be possible, you would then have the motors as backup in event the diesel stops.
Dick

[knighty]

ahh, I get you now..... problem is, the motors and compressors are all one unit, sealed up and air tight !


as soon as this guy get back to me with a quote for the magic box of tricks I should be able to move pretty fast !
sent him an email to chase it up, he said it would take a week.... but it's looking more like 2 weeks now...


I could (apparently) buy a grid tie ready generator from china for about 8k, but from what I can see, they're all 3000rpm units, and I don't know what they'd be like on veg

if he doesn't hurry up I might look at buying some grid tie inverters... something like 3 x these (for the 3 phase power)

3 would do to start with, but would really need to add more later on...

now I think about it....  if I used inverters, and run them from DC rectified from the generated 3 phase.... I could use something like Alans power controller thing to control the solenoid connected to the fuel rack to control the rpm of the engine..... so the engine could rev up/down depending on how much power is being used ?   revs/volts/frequency won't matter when it's being rectified to DC anyway (as long as it's within spec for the inverters)


that was kind of what my very first plans were.... but inverters were a lot more expensive then.... looks like they've come down in price a bit now ?

[knighty]

p.s. I was thinking about your system today, and separate rads vs heat exchanger connected into existing rads

and.... you could always do both ?

have your separate CHP rads and tie into your existing system with a heat exchanger....

no heat will be lost to the existing system unless your central heating pump is running..... so you could then add a thermostat on the pipe for the water going back towards the chp system to power on the central heating pump when the returning water gets hot enough ?

would be a pretty cunning way of regulating the chp temperature... too hot and the extra rads kick in.... cools off and they shut off so all the heat goes back to your chp only rads :-)

[jotec]

I like the idea of the FPHE in the house system. When the CHP is PLC controlled it would be easy to use that as a heat sink. Pity it would be no use in the summer when I heed to dump heat.

Inverters seem to be coming down, my idea of using the cheap windsaves was to have them for as long as they last and for experimentation (£150 fried is not as painfull at £1500) then get a good one later then the prices have stabilised.

The max you can put on 3 g83 is 11.5kw so 3 of those would work fine with a little bit of spare for another later.

Re 3000 rpm -  it is a lot to ask a diesel to run at that continually. I think I would look for something slower.

Re load control - how about a variable speed drive  (variamatic- rob a Daff if you can find one.). The diesel could then run at the best speed but the DC could be regulated up and down by the alternator speed.

"something like Alans power controller thing" can you point me to this post I may have missed it.

Keep thinking
ATB
Dick

[knighty]

http://www.navitron.org.uk/forum/index.php/topic,11700.0.html

that post (and the one linked in the second post of it)

not really what it's made for, but could work ?

for me, that would be something to be added later on, 11.5kw probably wouldn't cover the freezers running, so i could leave it running at that 24/7 and not worry too much...

it all depends on if the DNO want me to add extra meters etc..... I've got the old ones and I'm pretty sure they'll go backwards if I grid feed through them... of that works out (or they take there time adding the meters etc..) then I would be better off just back feeding !

[jotec]

Yes I  had read  that and forgotten about it I will have another look.

Interesting about your meters running backwards - if they do will you have to tell the supplier or is that their problem? If they are happy with it it is a much netter rate than the 3p export rate.

[knighty]

I don't really know about the meters going backwards thing.... my plan is to inform them of the install and then leave the ball in there court.... when I talked to a guy at the dno they said they probably wouldn't bother with meters because I'd be using so much more than I could produce

11.5kw 24/7 would only cover about half of my usage anyway, so it's not like I'll be exporting a lot!



EDIT/update
still waiting for the quote to come back, but I've found 3 phase inverters are much cheaper £/kw.... found a 17.6kw sunny boy one for 4k+vat,  so just short of 6kw per phase and I can get the VAT back anyway :-)    I'll email navitron before I buy one and see if they can source one, I'd rather give them the money when I find there forum so useful !

[billythesquid]

Hey buddy i found you

thanks for the tip

Tony