Hello All,
I get asked this weekly by some friend, neigbor or family member. The most recent was this week when talking to a forum member on the telephone about my "Turning wood into electricity" project. So I'll dump out some of seven months collected research sources that led me here to being a Listeriod owner.
Short answer: more efficient of my fuel and labor time. Here's why.
(Wife wants me to clean up my accumulated stack of info on welders/welding, AC gen heads, Permanet Magnet Generators, engines, mountings gasifiers ect., ect. and the Stirling and steam stuff is on the bottom of the pile at the beginning of this quest.)
I wont bore you too much with whats already been posted on this forum by adhall, Doug, Skeeter, Shipchief, and many other members here under other threads. Look in Advanced Search. I did.
Stirling engines: simple, light and compact, clean and quiet, ulitmate multifuel capable and modern sexy! !
You can Wikipedia history and general development. Here's where I found what's available Today in our power ranges:
http://www.infiniacorp.com   They currently make and sell a 1kWe Stirling engine with encluded/enclosed AC linear alternator. This is for sale and being used by:
www.gocpc.com   in a small compact BioMax 1.8kWt portable mobile gasifier plant. CPC shows an actual picture if you dig through their web site. Note the auger style chip/pellet fuel dribble feed into the top of the gasifier assembly.Next:Â
http://www.sunpower.com/index.php?pg=25This will put you on their Power Generations Publications page. You can see a development work from 1969 to 2005. Open up Micro Scale Biomass Power and you will see their 1.1kWe Stirling BioWatt engine being used. You can buy this engine too. It comes also with an enclosed AC linear alternator Free with the engine.
Yeah, 1kw aint much. But both are NASA speced with a 40,000 hour life cycle. Both companies show development of larger 3 and 5kw units but none in useage yet. Sunpower site from the home page and in some of the papers gives good numbers on thermal efficiency: improvement of 16-17% to now 21-23%.
For a bigger more useable Stirling engine go to:
http://www.stirlingengine.com/ecommerce/category-browse.tcl?category_id=2Â Â Â They sell a book showing how you too can make a 5hp/3.7kw engine. Doesn't look to be using any high tech, just lots and lots of fabrication on a one off unproven design.
The current Stirling engine long answer is: too small, too expensive in $$ or labor for no better efficiency.
Steam: good old iron and steel, proven engineering, also ultimate multifuel and slow, slow style romantic! !
For the very best article of todays what, how and why of steam engines read this article by a true steamer named Skip Goebel at:
http://www.backwoodshome.com/articles/goebel43.html   This is an article I think adhall refered to in the past. It in very well written with the math to back up to back up Mr goebels statments. He says it's cheaper, less labor to buy a diesel genset and fuel. Want to burn wood? Gasify and run in an IC engine. Still want to steam? Through his company Tiny Steam he'll build you a sealed bearing modern engine.
For a real steam treat look here:
http://www.pioneertelephonecoop.com/~carlich/RSE/RSEengines.html    the web site of Reliable Steam Engine Co. Current production engine kits from 4 to 200hp. Boilers too.
Wow! Makes me want too build his 5hp turbine kit with his Roberts bulk wood wood boiler.
Problem is: using Skip Goebels math it would eat up 30-40% More wood than gasifing through a Listeriod. My wood may be "free" but it still takes a lot of labor(mine) to get into a useable form.
The current steam engine long answer is: too labor intensive, still can't match IC engine efficiency and still a space (with the boiler, condenser,ect) and water hog.
So thats why I'm here with you all in Lister/iod land. I like it here.
Enjoy
SteveU.
O K links finally fixed now. I think. Sorry. SU