Micro CoGen.

For the past five years or so, I've run my small company off the grid using a 6kw light plant. It has a 1 liter, 3 cyl Mitsubishi diesel sipping a little less than half a gallon. My dream has always been to use one of my Changfa-clones (8kw & 12kw) at the house for Cogen. With two thirds of the BTU going out in heat through the coolant and exhaust, it makes sense. I also have some solar hot water collectors (three 3'x7' panels). My idea is to create a reservoir for hot coolant generated by the exhaust, engine coolant and solar panels. Optional would be an oil-fired heater and a wood-fired heater.

I look forward to your developments in hopes of implementing some at my house and shop.

Are y'all talking about the "Great Stuff" type expanding foam? I hadn't thought of that... figuring that it would compromise the cooling. But, as a water cooled engine, I guess not. What about the heavy stuff they put as sound-proofing for cars? Dynamat and Hushmat are two big names in that field. It can be molded to the surface and sticks to metal.

I know soundproofing diesel generators has been bounced around a bit before and I've already learned quite a bit from this forum. I have three "Changfa style" single cylinder water-cooled generators that I want to use in different settings. One will be for emergency power, mounted on a small trailer. Another may end up in a cube van for work. And the other... probably at my shop where I run my small business off the grid.

I understand most of the sound from a diesel is mechanical rather than just the exhaust. Mounted on a trailer, shouldn't that help a lot of the lower level thump sounds? Beyond that, I'm thinking of a plywood box, caulked seams plus some sort of sound deadening material. I can't afford the high end stuff so I'm looking for cheaper alternatives such as "brown board" used for house sheathing. What about leaving a space between the brown board and the exterior wall?

Products like Lizardskin are good for stopping metal to metal sound. I understand that wouldn't do much good. But what about heavy mass material like Dynamat. Again, it isn't attached to a metal floor or body... would it do that much good?

Creative ideas?

My plan is to do sound level readings before, during and after the project, seeing how each treatment cuts a bit more of the sound. Of course, I'll report back as I go.

Along those lines, I've been experimenting with desiccant dehumidification. I live in the South where humidity is a bigger issue than cooling sometimes. It also stands to reason that it would take less energy to cool dry air than wet. A desiccant wheel can dry the inside air and be recharged with heat from the generator (or solar or whatever). My thinking is a systems approach where different things contribute and we can reach the same goal with different means.

I've thought along the same lines, somewhat. Most of the 335,000 miles on my 2002 Ford 7.3 Powerstroke were running on WVO. I run my company off the grid using a 6kw generator usually running on WVO as well. My plan was to use my 8kw Changfa style (with a SERIOUS soundproofing doghouse!) during the winter months to provide power plus heat. Run it lots during the cold season when I don't need much electricity so that I build up a big fat kwh credit with the utility.

In my state (Arkansas) we get a full credit for every kwh we produce including using biomass (veg oil). Not avoided cost. But, I have a strong feeling my utility will only sign off on UL approved hardware. So, why not have some solar and get it hooked up with "approved" hardware. Then, what's the difference as far as they are concerned if I add more PV panels or a generator so long as it goes into an inverter/controller to produce grid-compatible power? Regarding net-metering, when I checked into it a few years ago, they knew it could be done but no one had a clue as to what it would take as for hardware.

I do have the veg oil supply and more than anything, I want to see how energy independent I can become. Someday... a gasifier. Been working with them for six years. Not a question of "if" but just a matter of working out the details. Lots and lots of details.

I have Bill Rogers' book. Man, talk about going over my head! I design chemicals and processes for a living. Reading that book just showed me how much I DON'T know about electricity. That said, I have a feeling that the only way to get our utility provider to sign off on an installation would be to use recognized off-the-shelf hardware from recognized providers in the renewable energy field. UL approval would go a long way.

And yes, I've thought about having a minimal amount of solar at least to get some tax credit. As for running a generator, our net-metering rules are written to accept biomass as a fuel. So long as it ties in to the grid in sync and has the required disconnect relays for when the grid goes down, I'm pretty sure I can get the green light.

In the past, talking to the inverter/controller manufacturers didn't get too far. They are into solar and frankly, the market demand is so small for running generators on renewable energy, I can't blame them for spending a lot of time on it.

Thanks for your suggestions, Mike. I'll check out the hardware you listed. Well, except for the Witte. I'm in oil country and would love to find an old Arrow or similar gas engine from the old days running pumps in the oilfields. I can remember hearing them all through the nights when camping out as a boy in the mid-'60s. Most were scrapped when there was a big push to go electric drives. And of course, a gasifier to run the engine on woodgas. But, that's for another day.

Thanks for your help, guys.

Without a doubt, I want to do it in full compliance. No desire to do otherwise. Few around here understand net-metering with a solar system. Forget thinking about running a generator. The US Forestry Service has a wood gasifier driving a 25kw generator set up for net-metering but that is big enough to do syncing of the power. In talking with Woodward controls, I find anything smaller just can't maintain a constant speed sufficient to stay connected with the grid.

I've considered some of the hybrid systems that allow AC input. Some say I'll need a complete bank of batteries. Some say only one. I understand the idea is to convert to DC and back to AC through a grid-compatible inverter-controller. I have a feeling the controller syncs with the grid and puts out AC that is safe for the grid.

For sure, I'd never think of running a motor backwards or something like that. Above board all the way. As for the SA200, my only thought there was that it would generate a DC current that an inverter-controller could handle.

Something else I've considered is setting up two generators: one creating AC power for use during outages and one generating DC current to make it easier to do net-metering. I have a 7.5kw as well as an 8kw Chinese horizontal diesel generator. Heck, I have even bounced around the idea of using an old Lincoln SA 200 "pipeliner" gasoline driven DC welder to make straight DC power.

My house was built in 1925 (pier and beam, frame house) and currently has a really old natural gas central heating system. The AC portion is likewise pretty old. My plan is to rip out the A-coil from the air conditioning as well as the gas heater chamber and install a liquid to air heat exchanger instead. Hot water/glycol will come from generator coolant, exhaust heat, solar panels and/or a waste oil heater made from Murphy's Machines (long time reader of the infopop.biodiesel forum). I could also install an outdoor wood fired heater.  I have already bought window units to use in lieu of the central AC.

I have Changfa style generators: 7.5kw, 8kw and 12kw.
 
I already have a stainless steel rectanglular open top tank approximately 134 to 150 gallons which I plan on using as a common reservoir. Pumps would be used to circulate coolant through the heat exchangers in the various sources of heat. Another pump would be used to circulate that hot glycol through the exchanger in the central heating system.

Could the existing A-coil from the central air system be adapted to handle hot glycol? I also have a couple of spare automotive radiators if they would help.

I've been told that I'm too far south (only 20 miles from the Louisiana border) to use radiant floor heating. I'd love it and have good access in the crawlspace below. But, I can see our temperature swings could be tough. It may turn off bitterly cold for a few days but then turn around and call for air conditioning a couple of days later. Do any forum members have experience with radiant under-floor heating in the South?

Arkansas has nice net-metering rules. Essentially, any electricity generated by renewable resources can be fed back into the grid at a 1:1 rate. Not avoided cost. KWH out, kwh in. We can generate a credit from month to month. Renewable energy includes biomass and biofuels. I currently run my company off-grid and am working on cogen for process heat. Most of my electricity comes from a diesel generator running on veg-oil based fuels (biodiesel and others). I have also been working with biomass gasification for the past six years.

I want to install a generator at the house, running on used cooking oil and/or biomass gasification. My plan is to run it during the winter, generating more power than needed and creating a credit with the power company. I'll also capture the exhaust and coolant heat for home heat. I also have some solar hot water panels as well. What are some options for connecting to the grid at 7kw to 12kw? Use a rectifier to convert it to DC and then come back through an inverter/controller for grid quality power? Ideally, I want to be able to have power during outages as well.

Any suggestions on the grid intertie options?

I've researched them for a few years and like you, I'm leaning toward Murphy's. I've been cautioned against drip type and even Babington type heaters in that you need to be nearby all the time to monitor the operation. Oils heat up and the viscosity changes. Different types of waste oil will have different viscosities. I want a system that will adapt. It looks like Murphy's design will adapt to variables.

I've followed him on the infopop biodiesel forum for years. He seems like a good guy and a solid fabricator. I trust his design. I have bought his plans. Just waiting on some bigger paychecks to buy a welder and plasma cutter from Eastwood so I can get to fabricating. In the meantime, I'm accumulating enough obtanium to make it happen.

My plan is to use various sources of heat: solar, waste oil, cogen from the radiator and/or exhaust of a generator. Use what is available with not only Plan B but Plan C as well.

Thanks for your reply. I decided to let this one slide. I'm going to wait on a water cooled Lister instead.

I have three Changfa clone Chinese water cooled diesel gensets but have always wanted a slow-revving Lister. Found a two cylinder air cooled that came out of the oil field. Runs good.

Is an air-cooled Lister still a good idea for long term running? Any feel for what size generator it would push? I'd like to get something down in the 850 to 1200rpm range. Slow revving, run it forever.

Any feel for what it's worth? The guy said he wanted $875 but that was his starting point.

A few months ago I asked about adding a "real" oil filter to my Changfa copy engines. Y'all told me about splicing into the oil line that feeds the head. Sounds simple enough... but where do I return the oil after it goes through the filter? One member said to drill and tap a port but where do you suggest adding it?

Also, I don't want to starve the head for oil. Should I add a metering valve to restrict the flow to the filter so as to keep most of it going to the head?

By the way, I'm going to start a sound-deadening project soon. I'll keep y'all posted.

Todd

Tell me about your 12v fridge heater. Off a 12v refrigerator from a motorhome? One of the 12v/propane units?

I'd like to incorporate some cogeneration to use the exhaust heat to provide the heat for the veggie as well as process heat.

How much hassle is it to drain the WVO back out of the tank after each run? How big a tank do you have for heating the veg oil? Does the oil stay hot enough in the stock fuel tank sitting on top of the engine? I was figuring on using the stock tank for the startup/purge diesel.

I'm eager to hear about the engine tear down!