Sweet... wood fired electrons...

[Telco]

http://stonepathpower.com/woodgen_info.htm

Got this off a performance truck board I also hang out at. 2.5KWH off a wood fired boiler, designed for residential use. No need for a backup generator anymore. Unfortunately, they aren't quite ready for sale yet, but should be sometime this year according to their website. Something like this would definitely make up for those low/no sun winter days if you are also using solar power...

 

[Redox]

The idea of a wood fired steam boiler kinda worries me...

 

[BrownianHeatingTech]

Many folks have attempted to bring things like this to market. Whether they can actually do it, and have a reliable product that won't burn out its turbine or stress-fracture a heat exchanger is always the question.

A number of folks are working on similar approaches, and some are working on some more esoteric approaches. But generating electricity with wood is a niche market that is gaining interest for certain customers. Once interest is high enough, investors will be willing to put up the funds necessary to bring designs to reality, and do it in a reliable manner.

Joe

 

[steam man]

This is right up my alley. There isn't any reason it wouldn't work except one-it has to cost a small fortune to own and maintain one. I suspect it could be used in some niche market such natural disasters where normal electrical power would be out for some time. Wood fired steam boilers are not a problem-they were used in locomotives and steam vessels for a long time. I would think a wood gas to gas turbine may be an alternate approach you could eventually see. Even a sterling engine could work. As BrownianHeatingTech says there are a number of plans out there.

 

[MarcM]

This is right up my alley. There isn't any reason it wouldn't work except one-it has to cost a small fortune to own and maintain one. I suspect it could be used in some niche market such natural disasters where normal electrical power would be out for some time. Wood fired steam boilers are not a problem-they were used in locomotives and steam vessels for a long time. I would think a wood gas to gas turbine may be an alternate approach you could eventually see. Even a sterling engine could work. As BrownianHeatingTech says there are a number of plans out there.

I'm dying for someone to produce a sterling engine sized appropriately for home generation of electricity. I use one of those long before buying something with the cost and reliability issues of a full steam turbine system. Dean Kamen is supposedly dumping money into sterling engine research. I hope we see something soon.

 

[steam man]

Steam turbines are probably one the more reliable prime movers available anywhere. They can run for years with no direct maintenance. There's one caveat-It takes the support of other equipment to make it function and there lies most of the maintenance issues. It all comes at a cost. There is a company that I've read about that does heat recovery with a sterling engine. I am researching various ideas to make electricty utilizing a wood boiler (with inspiration from this site) but don't hold your breath. I also remember reading about a company in the northeast that developed a small residential gas turbine years ago to generate electricty and then use the waste heat for building heat. Similar concept I guess.

 

[MarcM]

Steam turbines are probably one the more reliable prime movers available anywhere. They can run for years with no direct maintenance. There's one caveat-It takes the support of other equipment to make it function and there lies most of the maintenance issues. It all comes at a cost. There is a company that I've read about that does heat recovery with a sterling engine. I am researching various ideas to make electricty utilizing a wood boiler (with inspiration from this site) but don't hold your breath. I also remember reading about a company in the northeast that developed a small residential gas turbine years ago to generate electricty and then use the waste heat for building heat. Similar concept I guess.

There's a company now that sells an LPG IC electric generator that runs whenever the building calls for heat, and has a conventional furnace for any load above what the generator can handle... interesting concept.

As far as generating electricity from waste heat... or any heat... I think this invention holds a lot of promise:

http://www.popularmechanics.com/science/earth/4243793.html

And from the guy that gave us the Super Soaker, no less.

 

[steam man]

I've looked at thermoelectric generation-its not new but it sounds like the the super soaker is working the bugs out for more applications.

 

[Telco]

Very nice. There's always a way to do what you want, even if it hasn't been invented yet. Eventually someone will get around to it. Imagine, a solar power production device that works as well in the winter as it does in the summer, considering that while there is less sun there is also more of a temp differential.

Hey, anyone ever see those cheap magnifiers that are 8 inch by 11 inch, and designed to double the size of print on the page for people with bad eyes? Anyone want to try an experiment to see if some of those laid flat on a solar panel do? Since they about double the size of print, was thinking that they might double the amount of light that the panel receives without increasing the panel's temp by very much. Was thinking next time I go to the big city, if I think about it getting one of those camp PVs they sell to recharge a cell phone to see what the effect is.

 

[MarcM]

Very nice. There's always a way to do what you want, even if it hasn't been invented yet. Eventually someone will get around to it. Imagine, a solar power production device that works as well in the winter as it does in the summer, considering that while there is less sun there is also more of a temp differential.

Hey, anyone ever see those cheap magnifiers that are 8 inch by 11 inch, and designed to double the size of print on the page for people with bad eyes? Anyone want to try an experiment to see if some of those laid flat on a solar panel do? Since they about double the size of print, was thinking that they might double the amount of light that the panel receives without increasing the panel's temp by very much. Was thinking next time I go to the big city, if I think about it getting one of those camp PVs they sell to recharge a cell phone to see what the effect is.

Laying a lense over the same footprint of a solar panel won't increase energy absorption of the solar panel. A lense can only redirect energy, it can't produce it.

If you had a big lense (or several appropriately aimed small lenses) at the right focal distance from the panel, you could increase the incident radation... a similar affect can be achieved by using appropriately aimed mirrors, but all of those are mostly expensive and impractical solutions, since the sun isn't stationary in the sky.

Solar tracking parabolic mirrors are used in conjuction with sterling engines to produce electricity already, those setups like that require maintenance and are costly. They put the hot side of the sterling engine in the focus point of the parabolic mirror (techincally, the mirror is more of a paraboloid, actually, but you get the picture).

 

[renewablejohn]

Telco

my concerns with this are the steam boiler and the high turbine speed. Boilers are notorious for exploding which is why I use thermal oil as for the turbine they are very inefficient a compound engine upto 500kw is more efficient due to the losses on the rotor blades. If the woodchip woodgun could handle thermal oil it would be easy to connect it to a compound steam engine and generator as the technology is available off the shelf

 

[Telco]

MarkM- I understand what you are saying on the lens, was thinking that since it magnifies in one direction, it might concentrate in the other, perhaps it might draw more light in. I'll still experiment with it and see what happens, won't cost too much to get a camping cell and I think I've got one of those magnifiers.

Solarjohn, will just have to wait and see what that company comes up with for a product. They may determine that they can't make it work at a residential scale, but from the looks of the site it looks like they already have and are just fine tuning it. I really don't care how efficient it might be if it produces electrical energy with wood, because (provided they don't want 50 grand for one) I'd just be using it as a backup to solar cells anyway.

 

[slowzuki]

You don't understand, take one and go out in the sun and put a piece of paper under it spaced at the focusing distance, it will make a bright spot in the middle of the paper, the magnified area you see and it will shade the rest.

If you lay it on the paper it will do no magnifying because it isn't focused and it will be darker than just laying the paper out in the sun. The darker park is because it reflects some light that hits it.

If you use a small solar cell the size of the focused area when its not hard up against it, it will kick up the output because it is collecting light from a big area and putting it all onto the smaller area.

MarkM- I understand what you are saying on the lens, was thinking that since it magnifies in one direction, it might concentrate in the other, perhaps it might draw more light in. I'll still experiment with it and see what happens, won't cost too much to get a camping cell and I think I've got one of those magnifiers.

Solarjohn, will just have to wait and see what that company comes up with for a product. They may determine that they can't make it work at a residential scale, but from the looks of the site it looks like they already have and are just fine tuning it. I really don't care how efficient it might be if it produces electrical energy with wood, because (provided they don't want 50 grand for one) I'd just be using it as a backup to solar cells anyway.

 

[renewablejohn]

Telco

This machine does a similar thing without a boiler but uses woodpellets

http://www.sunmachine.com/download/datenblatt/datasheet_sm.pdf

 

[Redox]

A pellet generator! That's wicked! Can you send me one? Take USD? Oh well...

Renewable, you are a tease! We'll never see that here! We still can't seem to find any of those small efficient diesels, either.

One can hope though.

 

[Gooserider]

Telco

This machine does a similar thing without a boiler but uses woodpellets

http://www.sunmachine.com/download/datenblatt/datasheet_sm.pdf

Cute, but why can't they make one that runs on cordwood? I'm not even vaguely interested in anything that burns pellets...

Gooserider

 

[renewablejohn]

The problem is you need a consistent supply of heat to operate something like the sunmachine which you can only get on an automatic basis from woodpellets or woodchip. This is why I was looking to adapt a woodchip woodgun as you have the consistent supply of woodchip but the option to use cordwood.

 

[Telco]

Found an animation that shows it in action. Perhaps this will give someone an idea on how to build one using regular wood instead of a pellet stove. I'm going to let it circulate in the 'ol substrate for a while.

Slowzuki, that's exactly what I plan to do. Invest 5 bucks and spend a day playing around to see what happens before and after. If nothing works right, I've invested 5 bucks in a practical exercise, and if I can make it work right then I've potentially saved a few bucks in solar panels in the future.

 

[slowzuki]

The problem you'll find telco is that you need to buy dozens of small pvs, space them out on a board, then track the sun for it to work. If you don't track the sun you'll find they work terrible because they are shaded often. The other problem of spacing them since more PVs are a big sheet, not individual units ready to glue onto a base spaced out.

You really need a GIANT fresnel lens and a normal pv panel and sun tracking to do what you want on a house powering scale.

 

[Telco]

Renewablejohn - What about making your own? These guys claim they can make pellets with 15 percent or less moisture out of just about anything burnable.

Slowzuki - Sorry, I'm still going to give it a shot. It won't hurt me to invest 5-10 bucks and a couple of hours of time to see if my idea will work. Feel free to not do it if you feel it won't work.

 

[slowzuki]

Lol, sorry, just trying to save you some money using the laws of physics. Just to save you some effort, the lens must be larger than your solar cell for it to make any improvement. Its just conservation of energy, like you can't put a generator on the back tires to power and electric front wheel drive car.

Pellet pros have been around a while, the cost is in drying material for use.

Interesting link I found:

RICARDO
Military Radio Battery Charging Set
Single cylinder enclosed P.V. steam engine
Direct coupled to 6 Volt D.C. alternator.
Wood fired boiler.
Output 3-4 Amps ~ Wt 50 Kg.
A complete set, packed in wooden crate.
One of several currently available.

Renewablejohn - What about making your own? These guys claim they can make pellets with 15 percent or less moisture out of just about anything burnable.

Slowzuki - Sorry, I'm still going to give it a shot. It won't hurt me to invest 5-10 bucks and a couple of hours of time to see if my idea will work. Feel free to not do it if you feel it won't work.

 

[MarcM]

Telco

This machine does a similar thing without a boiler but uses woodpellets

http://www.sunmachine.com/download/datenblatt/datasheet_sm.pdf

I wonder if those guys would sell you just the stirling engine, and where they hell they get them from. I've scoured the internet looking for them that size, I was convinced they just weren't made.

 

[Telco]

No idear on if they'd sell just the parts.

Slowzuki, I understand what you are saying, but I'm a little hard headed. Since the cost is small I see no reason not to do this. Besides, I may come up with something. After all, whudathunk that you could get milk, meat and electricity from cows? NOTE: Lifted this from another post.

I'm looking at it as a fun little project. Next fun little project involves an old dryer, a bunch of heater cores, some copper tubing and some water....

 

[slowzuki]

lol thats fine, besides, the solar cell will work fine once you take the fresnel shade off it hehe. The next project sounds better to me! A hydronic dryer unless I'm mistaken, or maybe its a still!

No idear on if they'd sell just the parts.

Slowzuki, I understand what you are saying, but I'm a little hard headed. Since the cost is small I see no reason not to do this. Besides, I may come up with something. After all, whudathunk that you could get milk, meat and electricity from cows? NOTE: Lifted this from another post.

I'm looking at it as a fun little project. Next fun little project involves an old dryer, a bunch of heater cores, some copper tubing and some water....

 

[Telco]

Hydronic dryer. Seems too simple and solves the last problem I saw with going offgrid, the drying of clothes. We have little enough time to deal with laundry as it is without adding hanging clothes on a line and waiting for them to dry naturally.

On the solar cell, when I get it done I'll post a nice, long new post with the results, good or bad. I'm not one to hide from being wrong about something.