Steam turbine engines?

[Scott Graham]

Hey craftwebbers,
Long time reader first time poster. The other day I was talking with a friend who wants to move to the dessert and use solar panels to create electricity for his house. He hopes to create enough electricity to sell back to the electric company. The solar panels have copper pipe filled with water run through them to create steam that runs a turbine engine, creating electricity. Okay. So my thought is that if you can efficiently create electricity using heat from the sun. How difficult would it be to set up a system using waste heat from the hot shop. Can this be done? Has this been done? I have just started to research on this and thought that I would share my new research project. Any thoughts? Is there a way to subsidise our hot shops? Thanks for any thoughts or info. -----Scott-----

[Jordan Kube]

I've been thinking about this one for years

http://www.youtube.com/watch?v=fUrB7KRvxUk

http://www.youtube.com/watch?v=vCleMqdGqug

http://www.youtube.com/watch?v=PBNoD-q2ERA&feature=user

[Scott Graham]

So more thoughts. Once again still researching this. I was thinking the easiest way to se this up would be to contact one of the solar companies and see if it is possible to buy thier kit minus the solar lenses. So basically just buy thier engine setup with all of the info and connectors to the power grid. Instead of using solar lens a tank could be used instead. Questions? What are the temp ranges for this system? Woud you have to step down the temp or maybe run more engines?

[Glenn Randle]

I used to wonder about the same thing. So I asked at an engineering forum and it was quickly pointed out how small our excess energy really is.

For example, if your furnace consumes 1 gallon of gas per hour and is 50% effiecient the remaining waste heat which is exhausted is only 1/2 gallon per hour (this is ignoring the all the energy losses due to what the heat exchanger can't catch, and other conversion losses along the way to becoming electricty).

Then think about how much fuel even the smallest portable generator consumes to produce 2000-3000 watts. Say, a 5hp unit would use 2-3 gallons per hour (an estimate). And you're trying to get something worthwhile (your time & money spent) from less than 1/2 gallon, probably a quart, of fuel per hour....it just isn't enough to run any size of generator.

I'm not saying there's nothing the wasted heat is useful for, but it would probably be best to use it as a "heat source" rather than trying to convert it into motion.

[Brian Mazrim]

Hey Scott. You've been talking to Rich? From what I've read in the past, I think the most efficient systems for converting solar heat to steam use big lenses to focus light onto a pipe containing oil. The oil is then flows to a heat exchanger to boil water. The oil holds its heat better while being piped around, and can carry a lot more heat without turning to steam or developing inconveniently high pressure. That kind of system could probably handle the temerature in your flue. Then there's the turbine, inverter, transformer, controllers, pumps, boiler, and plumbing to think about.

[Scott Graham]

Okay I understand what you are saying. But how is it possible for this system to work so efficiently from solar panels.(which only collect energy during daylight hours) V.S. from our furnace wich runs 24/7. I would assume that there is enough heat from the furnace to create enough steam. Once again I am still researching this and do not have a lot of engineering knowledge. :confused:

[Brian Mazrim]

Well, thats the rub-- solar energy isn't efficient, it's just free and non-polluting. Photovoltaic energy is the more useful conversion from solar, but here's a bit from a website by a guy who seems really into alternative energy:

A 9-foot in diameter solar furnace, even under optimum conditions, will turn a cup full of water into steam in about one hour. A 1 hp steam engine, the smallest we make, requires 3 to 5 gallons of water turned to steam every hour. Worse, a medium-pressure steam engine (80 to 150 psi) requires incoming steam as hot as 366 degrees F. (150 psi). The steam that leaves the exhaust port is still at 264 degrees F.

If I read it right, a 1 hp engine can power a 500 watt generator. So maybe thats the math you need to figure out-- how many gallons of water can you boil in an hour from your waste heat?

[Eben Horton]

heat a hot tub with that waste heat and enjoy yourself while you bask in the time you just saved by not making some wild contraption to save 10 bucks a day... life is short.

[Scott Graham]

Maybe complacency is the way to go? Why be progressive? Technology seems to be changing all the time, but not in the glass world.

[Larry Cazes]

Well, thats the rub-- solar energy isn't efficient, it's just free and non-polluting.

The last time I looked enough cells to be useful along with all of the needed infrastructure was anything but free :)

[Dave Bross]

Uhhhh-ooooh, is it time to roll out the the thermal flywheel, the whack-a-mole mallets and the tinfoil hats?
Understanding this statement may require a trip into the archives if you've not been around here for a while. No glassworkers were harmed in the making of this fantasy.

Eben nailed it. Charles F. has been basking in his glory-ous hot tub for years.

Hmmmmmm, complacency?

Well, unfortunately, enthusiasm isn't going to reverse the laws of physics. Particularly that really pesky one about entropy... it's not just about lazy old glassblowers rotting away mentally anymore.

[Garner Britt]

Maybe complacency is the way to go? Why be progressive? Technology seems to be changing all the time, but not in the glass world.

I think the advice given have been quite progressive. The idea of doing ANYTHING with waste heat is fairly new to most glass blowers.

Heating hot water for a hot tub (or home heat) is a brilliant and very do-able project. Using heat for heat just has a certain effeciency that converting heat to steam to motion to electricity, does not.

The solar thermal systems I'm aware of that generate electricity are large (acre or more) trough systems with fresnel lenses that get a fluid (not water) really hot. Then there are the various roof-top panels for domestic hot water and heat.

If we want to truly do some thing amazing with excess heat, lets figure out how to COOL our hotshops with it....must be possible if you can run a refrigerator off propane...

garner

[Dave Bross]

That type of refrigerator and a lot of big commercial freezers work by boiling ammonia (this happens at a very low temp. as compared to most) to take advantage of the liquid to gas cooling effect.

The catch is that leaks are very toxic to fatal depending on the concentration in the air.

[Scott Graham]

Okay everybody I agree that the info given has been helpful. Thankyou Brian. Im not even saying that this "fantasy" is possible or that I am going to be creating some "crazy contraption", but I was curious about the possibilities. True, heating a hot tub or your house is progressive, and I plan on doing that. I just didn't like Eben's comment. It seemed dismissive and complacent. I didnt mean to offend any old time glassblowers egos.

[Michael Stoddard]

heat a hot tub with that waste heat and enjoy yourself while you bask in the time you just saved by not making some wild contraption to save 10 bucks a day... life is short.

Ugggh, I imagine jumping into a hot tub after a nice long day blowing glass might sound a little better in the winter. If there was some way to make a cold mountain stream to jump in with waste heat; that would sound a bit more refreshing right now.

[Eben Horton]

move the tub to the north side of your studio in the shade :)

[Eben Horton]

One thing to consider, is that if there is 'X' flying out of your flu, you obviously can not reccoup 'X'.. But, you can gather enough energy to heat 'Y' which could be a hot tub, or what ever.... It is very easy to capture the heat and pump it somewhere... that is what I was getting at- but to spend hours upon hours to make something complicated that will only save you a few bucks is your own priority-

A few years ago someone was waxing poetically about what great efforts they go through to save a few bucks on propane a day and i replied back that I will just make another piece to cover the rising costs of fuel..

I guess I look at things differently. I am not wastefull, but I work smart.

[Paul Thompson]

Hey craftwebbers,
{snipsnip}a friend who wants to move to the dessert and use solar panels ... {snipsnip} ... filled with water run through them to create steam that runs a turbine engine, creating electricity. {snip}
Is this a different desert than the ones I've seen, which run on the dry side? Is the water vapor recaptured after it's brief spin through the turbine, or dumped into the environment? How much water would be needed per day, and from whence cometh it?

[Hugh Jenkins]

So you make an extra piece each day to compensate for the electric increase, and then another for the propane increase, and at least a good one a month for the health insurance increase, and then another for the increased price of vegetables, and then.... When will you be basking in your glory?

However, the KISS policy should apply. Get the most good with the least expensive system. Hot water is the simplest. Get a solar Delta thermostat and you can circulate water through a basic radiator type air to water exchanger and into the tub or a tank or a pool, etc. Steam is possible but not in the huge volumes needed, especially if you already have recuperated and have exhaust in the 600 to 800 range. Always install PT release on any hat water system.

I am on the road this month doing installs. Many interesting situations occur in the different shops I visit.

[Dave Bross]

The Massachusetts town I lived in in the early 60s burned all their garbage to make steam and make electricity. The thing burned hot enough to melt an engine block so minimal (for that time) pollution, and of course now there's effective smokestack scrubbing tech available.

A lot of industries with combustible waste did the same thing back then.

On a smaller scale, same era, there was a guy in Denver who bought a small woodstove and then started getting everything he could in the way of junk mail. I'm sure his mail carrier was thrilled.

Anyway, no shortage of combustible waste out there at the moment. In a perfect world we would be less wasteful....but I don't see that anytime soon.

[R. Scott Johnson]

anybody out there running their suv on water?
http://www.watertogas.com/browns-gas-electrolyzer.html

[Ben David]

The people successfully living off the grid are usually combining photovoltaic panels with either windmills or hydroelectric power. Assuming there is no river flowing through your friend's desert property, s/he may be able to set up a system with wind and PV.

It takes a lot more energy to turn water into steam than it does to raise the temperature of water. So forget about turbines, and recover the waste heat as best you can.

[Pete VanderLaan]

Eben is right.

It would take a collector the size of a football field to collect enough hot water and even then it would need to be boosted to turn it into steam. I live in a house run entirely on wood right down to the hot water heater. Right now I am cutting sixty (count em) cords of wood and splitting it. It takes a boatload of time and gas for the chain saws ( all three) and the tractor and it's big assed splitter. It is only viable because I own a large forest. Then again with fuel oil running at close to five bucks a gallon, I may sell wood this fall. I expect it to go over $300 per cord- delivery extra.

[Dave Bross]

I know everyone is excited about hydrogen or Brown's gas but that takes a lot of energy in for not so much out. There's our friend Mr. entropy again.
There's also some thought the hydrogen exposure eventually makes the iron in the motor brittle too. That would be profitable for those selling new cars and junking the dead ones.

All right Pete! A woodlot is going to be a VERY valuable thing in the north. Soon you'll be melting 104 coe in your wood powered furnace just like a 14th century Italian!

We've got tons of wood in Florida. A cord of oak is about $40-60 bucks. Now if we could just afford to ship it north...although some more of that ol' timey technology might be good here. Can you say trains? I should probably do my "Summer of Amtrak" on that one month pass pretty soon...before everyone else figures it out.

[Pete VanderLaan]

A cord of firewood in Southern California runs about $500.00. Getting it there probably would cost $200.00 from Northern California. If everybody burned it, you wouldn't be able to see your nose.

We heat what we can in the house and barns with wood and will pass the savings along to the propane company for the gloryhole. I try to go and split wood for an hour each morning at a minimum. More just wears my back out. Now I have the splitter attached to the tractor and the saw in the bucket. When I go in the woods. I can cut some dead and down and split it on the spot and just stack it for later gathering. It falls faster than I can burn it.

Selling it is something else. People are amazing. They want it a certain length, which I can understand but wanting a certain color mystifies me. Small vs large logs is an issue. Small can be nice but it burns faster. Large is heavy but burns slow. Developing a clientelle that doesn't bitch seems to be a good plan. It's the equivalent of avoiding a glass ornament market.

[Ben David]

I know everyone is excited about hydrogen or Brown's gas but that takes a lot of energy in for not so much out. There's our friend Mr. entropy again.
But a little pure hydrogen and oxygen go a long way... If you use wind or sun to generate the smallish DC current used to split the water into Brown's gas, you are not paying for the input energy (once you've paid off the solar panel).

Injecting even small amounts of H and O in your fuel stream will boost temperatures, burning efficiency, etc.

Weekend Warriors could bottle the gas all week.

All right Pete! A woodlot is going to be a VERY valuable thing in the north. Soon you'll be melting 104 coe in your wood powered furnace just like a 14th century Italian!
There's lots of waste wood around - it's just called cardboard.

One day we may be blowing glass using pellet furnaces... one of the most efficient ways yet to burn cellulose.

Tell yourself you're looking for cellulose instead of trees, and even desert places (like Israel) have a lot of fuel hanging around.

[Jay Holden]

Uhhhh-ooooh,. it's not just about lazy old glassblowers rotting away mentally anymore.


Hey, I resemble that remark.
Jay.:violin:

[Jay Holden]

Eben is right.

It would take a collector the size of a football field to collect enough hot water and even then it would need to be boosted to turn it into steam. I live in a house run entirely on wood right down to the hot water heater. Right now I am cutting sixty (count em) cords of wood and splitting it. It takes a boatload of time and gas for the chain saws ( all three) and the tractor and it's big assed splitter. It is only viable because I own a large forest. Then again with fuel oil running at close to five bucks a gallon, I may sell wood this fall. I expect it to go over $300 per cord- delivery extra.



Man Pete that's 180 face cord of wood. I usually burn 12 face cord a season.
I totally heat with wood also but I just purchased a coal furnace. I can't cut wood any more and my son is too lazy to do it. I can buy pea coal for $5.00 a 25# bag. The hopper holds 100#s and lasts for a week. The stove is going where my wood stove is in the dining room in the center of the house. Actually I traded my Lincoln for the stove even up. Needed a new starter any way.
Jay.