Have you stopped to really Cosider Micro Co-Gen

[Lloyd]

4. Conclusion

Micro-cogeneration for the decentralised production of electricity and heat is already
technically viable, with several types of systems available in the market. It is now
economically viable, with the possible exception of systems that use PV conversion. An
analysis of different available systems, in different European countries, showed payback
times generally between 3 and 8 years,

http://www.google.com/url?sa=t&source=web&ct=res&cd=38&ved=0CBsQFjAHOB4&url=http%3A%2F%2Fwww.kosecc.org%2Fxe%2F%3Fmodule%3Dfile%26act%3DprocFileDownload%26file_srl%3D281%26sid%3Dc1721b0670e6edeaaf031bdb32273e8a&ei=go2cS9S9E5D-sgOyot2_Aw&usg=AFQjCNEZjXUy15E6Oy3GUX3kiymreva4WQ


Comparing the pay back of PV systems of 25 year average...and a true Co-Gen system of three to eight years. The answer on the base system seems to be a no brainier....has anyone here done a comparative analysis between PV & Co-gen. What are your results.

I'm thinking PV is a good additive, but the base is a CO-gen, with just the right amount of PV.

What are the your kw needs per 24 hr period?

Lets all get together and create a matrix, and determine the investment and payback of both systems, 1. base sys=Co-Gen and 2. base sys= Solar PV

I'll help build the data base/spredsheet.

Any takers?

Lloyd

[highwater]

I have my electric consumption and $ spent, as well as the NG consuption and $ spent for the last 10 years, in Excel.
I am just starting to gather components for a standby-cogen system, so I would be playing catch up with most on that part.
But would participate.

Randall

[Jedon]

I've considered it but am not convinced it's the right thing for me. I'm off grid wirh 780W of PV, a Lister SR2 and a Metro 6/1. Next power project is some hydro which should take care of the remainder of our power needs. I heat with wood and don't have AC. Water is heated with a on demand 192K BTU which I would like to suppliment with some solar thermal. My generator shed is 150ft from the house, 220 by pipe, seems pretty far for hot water? This time of year when the sun is out I run the SR2 from 6 to 11pm. I guess if I were to try and scavenge some heat I would use a heat exchanger in the shed to bump some liquid up to higher temps for transmission to a radiative heater or hot water tank?

[mobile_bob]

have i ever stopped to consider cogen?

interesting question 

my journey of rediscovery started in '98 when i started to read everything i could find on the subject.

then came the separation and eventual divorce, during which time i ran my "walden pond" experiment
in living small, i lived in an apartment that was just under 235 sq/ft for about 2.5 years.

from that i determined that as a single guy i could live comfortably on about 2.5kwatt/hrs of power per day
and cogeneration to provide for that power and also harvest the heat for domestic hot water would make for
a very efficient and self sustained installation.

i next figured on a system that would provide twice that so as to cover any other unforeseen issues, then the inevitable
happened,, i met a wonderful gal and got remarried,, so...

the size of the planned extreme efficiency house powered by cogen doubled in size, which by modern standards is still quite small
at under 1000 sq/ft (i tell her 1000 sq/ft, and i am targeting for 800 sq/ft)

the s195 is just about a perfect match for the needs of the planned home, so that the heat balance is sufficiently high enough to keep
overall efficiency very high, high enough to compare favorably with grid power after factoring in all the extra fee's they tack on the base kw/hr
charge.

there is no way i would consider running any engine for the generation of electricity only, the cost of that power is such that solar, or wind would
be a much better and less expensive route for me to take.

in my opinion, and good cogen probably will have to incorporate batteries, and inverter, large thermal storage, and also in my case
a means of providing refrigeration from the excess heat in months that i don't have a better use for the heat (ie summer months)

my plan calls for 2 - one hour runs per day, one hour in the early am to recharge batteries and my hot water tank, and another hour
in the late afternoon to recharge batteries and recharge the hot water tank, during each run time all the heavy loads will also be provided for, such as clothes washing and drying (wash a load in the am, dry it in the pm)

one unknown to me at this point is how much solar power will play into my plan, i have a few kwatts of panels now, and they likely will dramatically reduce my engine run times a good portion of the year and on days that i don't have heavy loads to contend with.

the other unknown to me is the site i have has an east west ridge that is perpendicular to the predominate winds of summer and winter
the average windspeed up there is in the 12-15mph windspeed regime and could provide for all the power i likely would need over about 11 months of the year, (august is the doldum month), the problem is my bad physical condition and fear of heights, would limit me to smaller units that
were mounted on tiltup towers.

the cogen or in my case the trigenerator is my first line of power production, and must be as bullet proof as i can make it, this allows me some
peace of mind when it comes to solar and hail storms and allows me time to work out a reasonable windgenerator system that fits my needs.

so the short answer? yes

i have considered cogen, but as a part of a larger system

bob g

[Chris]

Bob,

What I have, which is a stop gap system right now (Off Grid), is a propane refidgerator. It's a bit small but OK and works well.
Propane water heater
Propane dryer
8 golf cart batteries
1.5KW inverter.
I used to have a Trace SW2512 inverter/charger. It went KAPUT. Not worth fixing.
2 Auto garage type 12volt chargers. One up to 40 amps the other 60 amps. I only use one on the golf cart batteries. The other is a spare. The charger is on when ever the gen is on.
2 generators. one 4.25KW lister VA (Aircooled lister 8/1)
the other John Deer 19 KW used mostly in the summer for A/C or when I am not around to start the Lister. This unit is too big. Long storey about that. This unit WAS with an electronic control panel that went KAPUT. I cobbled up a new controller using auto type 12v relays. I will draw this up some time soon before I forget what I did and post it under "Controllers etc".
200 watts solar panels.
Sun Frost Refridgerator 120 volts on when gen is on. Use it for canned or bottled stuff. Beer, Rum, cokes etc that can get warm if gen is off too long.

120 volt pressure pump to pump water up to my house. About 40 foot head to the house. A 12volt pressure pump for when the gen is off pumping from a holding tank at the house.
Wish list
One KW solar panels may be more
Outback 3624 inverter/charger
8 6 volt Rolls batteries
other stuff, charge controllers etc.
Solar water heater

Regards,

Chris

[BruceM]

I'm not able to take advantage of co-gen hot water, as MS brain rot has affected my hearing such that typical generator noise is very bothersome.  Thus my interest in the Listeroids.  I had already placed the generator shed over the hill from my homesite hollow; with the Listeroid 6/1 at 650 rpm, that means that in most cases it is completely inaudible, in some cases, with no wind and no bugs, it's chug, chug is barely audible (and not at all bothersome for me). The sound of a fly within 20 feet will drown it out.  

I like my fairly large Diamond brand propane refrigerator for it's quietness and modest fuel use, it has 3 cubic feet of freezer space.  That leaves only lighting and computer use for my 120V battery bank and 800 watts of PV.  Lighting is direct 120VDC incandescent as I don't tolerate CFLs and am waiting on LED panels and tubes to come down in price. (I'll have to modify them for 120VDC direct use, with no switching supply.)

I have an excellent site  on top of a hill for a tilt up windmill near my pump house/battery bank, and hope to add that someday.  All AC is provided by the Listeroid, there is no inverter.  Water is gravity fed, from a 2000 gallon storage tank at 12psi, which works fine as the pipes were oversized and flow restrictors are just removed from faucets.  Even on an outside hydrant (1 1/2" PVC to the hydrant), the low pressure is only a problem when you extend a typical garden hose beyond 50ft. (Bigger ID hose solves the problem.)  The house is heated by a small propane hot water heater, via 10 watt circ pump and in floor radiant heat.  I hope to add solar hot water but will defer that for now.  A separate 100AH AGM battery on 65W PV in the shop serves the circ pump and other minor 12V use in shop an house.

[Fat Charlie]

If you're burning something to create electricity, you have to consider co-gen if only to realize just how much energy you're missing out on.  I have no intention of capturing exhaust heat, but I've considered it.  It's too much hassle with too little payoff- for my situation.  Capturing coolant heat doesn't make sense for others' situations- but you have to at least consider it before deciding against it.  I've glanced at solar water and air heaters and decided not to do anything about them for the time being, but once the genset is sorted out that's going to get a lot higher on my list of things to figure out.  It's free heat in my yard that I haven't bothered to harness.  There's no law saying I've got to turn it into electricity first.

Co-gen is why I'm here.  All I really wanted was a backup generator, but nothing at Lowe's Depot has the kind of efficiency needed to make it worth the money- and how much gasoline am I supposed to store, anyway?  The best idea I could come up with involved a bank of a few car batteries to keep the furnace going, because I'm not going to burn gas all night just to keep the heat on.  Then last fall an off grid friend showed me the 6/1 that backs up his solar, and I knew I'd found what I needed.

It just makes sense.  I'm already burning oil for heat.  Next winter I'm going to do it in a way that creates a very useful byproduct- electricity!  It's a slow project, because I'm not going to screw around with tapping into my heating system until summer, when I don't need it.  I'm curious to see what kind of heating I'll get from it and how oil usage compares.  Considering that I'm going to be comparing oil usage to oil usage plus electric bills, I expect the CHP system to look pretty good- for half of the year.  When I don't need heat, I don't expect to have this system running. 

The "cost" of my co-gen system is going to be vague.  Do the welder, engine hoist and other tools count against it?  How do the free exhaust parts get factored in?  I'm also not counting my time, either spent working on it or researching/shopping.  Payback?  That's going to happen with the first power outage.  Any possible cost savings from co-gen vs. grid power plus oil heat are going to be icing on the cake.  I'm looking forward to seeing what my numbers are, and I'll pass them along.

[Lloyd]

Don't have time today....

But I wanted to give this link to everyone.....it should be in all our tool boxes.

http://www.supergen-hdps.org/special/ottawa

There's a lot of info...to collect if you take the time to read.

Lloyd