Steam Power for off grid electricity & heat

Hi All; Been off grid now for over 30 years. Started out with solar and after moving a few miles I was able to develop a micro hydro setup that produces 120+ watts 24/7. Between the solar (if the sun shines) and the hydro I get most of the power we need. I do have a remote start generator that we use for high draw appliances and of course the inverter is recharging the battery's at the same time that the genny is running everything else. Two years ago I discovered rocket mass heaters ! We have a greenhouse/ artist studio that we heat all winter long and with the rmh its amazing how much less wood we use... Recently I came across a web site about steam engines (http://www.mikebrownsolutions.com/mbsteam.htm) Certainly not for everybody,cost is very much a factor but the possibility,s are fascinating.
Steam Engine with Alternator DC Electricity Off Grid Brass Oiler Boiler
( 261709676254 ) I found this unit on ebay it has no boiler and its not cheap but.... if I can locate a surplus engine... and buy a boiler... I can build this. I'm thinking that in place of running the gas generator I can run a steam engine and the exhaust can be plumbed into the greenhouse while the engine spins a genny to recharge in the house. Heat and electricity! When they stop delivering gas & diesel to the local store I can still pick up dead sticks to burn in the steam genny and the RMH ! How bout that.. power and heat ! Now before I get responses warning about the (boom squish & burn) possibility of working with steam I will mention that I have several friends in the boilermakers union who will guide my every step and I have one other friend who is a certified boiler operator... Certainly not for the average person to jump into but for the right person with the necessary skill,s or friends , this is chock full of possibility!

I'm thinking of doing something similar, Thomas. Have you seen the green steam engine. Com website? They sell Steam engine and boiler kits that are much less expensive than the mike brown engine you mentioned. My understanding is that a tube boiler is quite safe without the explosion risk of a conventional boiler, and it also lends itself well to integrating into an rmh (you've just got to put a copper coil in there somewhere). A proper pressure release valve and you're good. I want to build an rmh with tube boiler in my greenhouse to heat the gh and my home and power a 10hp green Stream engine. The boiler will also provide a source of steam (Steam sauna, anyone?) And distilled water. If the exhaust from the rmh is as clean as they say it is (this would need to be field proven), I could feed the exhaust into the climate battery of the greenhouse, making the rmh truly 100% efficient with the added bonus of dumping all that co2 into the gh for the plants. Like I say this would require proofing with a gas analyzer for sure, but incredible possibilities for an off grid greenhouse/home with some old/low tech!

Steam is awesome, but comes with strings attached.

You seem to have a good grasp of the strings already, but I will list a few for those who don't know.

Steam engine/boiler systems require (pretty much) constant monitoring to prevent very bad things from happening.

The steam coming out of your tea kettle is almost nothing like live, pressurized saturated steam.

At real operating pressures, a gallon of live steam has about the same energy content as a stick of dynamite.

Steam boiler explosions are typically far more energetic than say, gasoline explosions.

If you do it really well, the steam system will have 1/3 of the efficiency of a decent internal combustion engine (offset somewhat if you can efficiently use the "waste" heat from the external combustion and the exhaust steam.)

Expensive.

Requires several skills the most people don't have, in terms of maintenance, running, adjustments, repairs.


Mike Brown is the go to guy for this size system. Of course, you can run them on anything that burns. And they are absolutely fascinating and are low tech enough you could fix and repair them for decades with the right skill set.


The Green steam engines have received a lot of criticism from the hobby steam people. Here's one example.

http://kimmelsteam.com/green-robertengine.html

And here, they go into some detail. The "plans" don't contain any drawings or dimensions or a very specific parts list...

http://www.homemodelenginemachinist.com/showthread.php?s=17c3a71b6c993f2fe90dd85b57562ef0&t=2223&page=2

Troy,

Thanks for the counterpoints, I hadn't seen anything critical of the green steam engine. After checking out all the criticism, I almost wrote that option off. But there is one guy on YouTube (https://www.youtube.com/channel/UCNwdzF4vPS-nNnDbMcaSwiw) who has built a steam engine and monotube boiler, and he's put about 50 videos up detailing the build. He's got the thing built and currently runs on compressed air. Looks like he'll have the thing running and making power on steam in the next few months. I'll watch and wait to see how it performs.

Jeff

Which steam engine you run is much less significant than which boiler, in terms of safety.

There are a few steam forums, I would double check your plans against the forums, and really, a boiler engineer, just to make sure you're not making any life and death mistakes.


Pretty interesting video on his home brew monotube design. Every boiler design has pros and cons of course. The big restriction with the monotube design is that they don't throttle up or down very well. They're fine for a steady load, but not so fine if the load goes up and down.

I'm not convinced his design is robust enough. I'm about eighty miles away from being a boiler engineer, but I see issues like pretty much guaranteed galvanic corrosion problems because he mixes and matches several materials that don't play well together in the presence of heat and moisture. Hidden corrosion and pitting are a definite failure mode in boilers. Monotube boilers aren't so explody compared to some other designs, but still nothing to trifle with. He does have a pressure relief valve, but I'd bet you a dollar it's rated for water, not steam.

My first order guess suggests that he will be lucky to get 300 watts out of it. Maybe that's all he wants, I haven't watched all the other videos.



The steam boat and steam train people have proven designs that are quite accessible.

The Harris book on boilers and boilermaking is really worthwhile and not so expensive:

http://www.amazon.com/Model-Boilers-Boilermaking-K-HARRIS/dp/085344109X

When I saw him securing copper tubing with galvanized steel pipe strapping to the riser, that was my first thought too - galvanic corrosion. I'm very curious how much power he can get this to put out - the inventor claims this will put out 10hp, I guess you could say I'm a little skeptical.

Jeff Thorpe wrote:When I saw him securing copper tubing with galvanized steel pipe strapping to the riser, that was my first thought too - galvanic corrosion. I'm very curious how much power he can get this to put out - the inventor claims this will put out 10hp, I guess you could say I'm a little skeptical.

A horsepower is just over 700 watts.

If he gets 7,000+ watts out of it, I'll buy you a steak dinner. Let's assume 90% efficient conversion of shaft horsepower to electricity, .9 x 7,000 = 6,300 watts of useable electricity. If he even hits 6,000 watts, I'll buy you a steak dinner.

I think some people who posted here that are interested in generating electricity by burning wood, creating steam with a Combined Heat and Energy system may want to check out my work.  I have made some videos showing my system design.  I just increased my steel water tube boiler pressure vessel to 3 cubic feet from 2.3 cubic feet, the videos were made with the smaller volume boiler.  I recently built and tested a piston steam engine I designed hooking it up to the boiler I built in 2009:
 [youtube]https://www.youtube.com/watch?v=9EatcjRgnd4[/youtube]   I estimate this boiler and piston steam engine has put out 1200 watts but it is not yet reliable.  I had previously built several turbines and tested them and also piped the exhaust from the turbine into my garage and heat the garage that way and also have a low/no pressure radiator loop system to heat when I am not generating electricity:  [youtube]https://www.youtube.com/watch?v=bTjikSKJUH0&t[/youtube]   The turbine has been in service for two years now and seems reliable and easy to operate compared to the piston set up but has only put out about 650 watts on the same boiler as the more efficient piston engine. I have studied code and law of my state and several other states and found this system to be legal in many states. I would like to actually go into business building and installing the complete system and supplying parts of the system to people who build some of the equipment themselves.  Please let me know what you think. Thanks Ken Driessen