Zenman open source steam engine = low cost home solar

[MitchJi]

Hi,

For more information see Zenman Energy.

Or to donate to Zenman (a non-profit) to help them reach their funding goals.

http://www.treehugger.com/solar-technology/open-source-solar-energy-zenman-energys-solar-steam-engine.html

Zenman Energy is currently developing a low-cost solar steam engine generator in a bid to drastically reduce the installed cost per watt of home solar, with the aim being to help get solar power plants built that will cost less than any other form of electricity generation. With coal at $2 per watt installed, that's a mighty lofty goal, but because the company will be giving away detailed construction plans after the prototype is complete, they hope that their open source model will further improve the design and reduce the cost of the units.

"Zenman Energy is attempting to create a low cost solar steam engine generator. This generator works by focusing a large surface area of sunlight onto a smaller area. The energy in the sunlight concentrates and produces vast quantities of heat. To increase the amount of energy, we increase the surface area of sunlight. We convert this heat into mechanical energy by boiling water and turning a steam engine. The steam engine will power an electric motor which ties directly into the power grid." - Zenman Energy

The concept of solar steam engines is not new, although most other installations of concentrated solar arrays are quite large. Zenman wants to create a solution for creating grid-connected solar power plants of any size, from residential to utility-grade, at a lower cost than current PV installations.

Right now, the company is building their first prototype, which powers a 10hp motor expected to produce a little over 7 kw. According to Zenman, this size of solar plant would be enough to power a single home (averaged to roughly 29 KWH per day), with 5 hours of sunlight each day generating about 35 KWH per day. But because these are grid-tied generators, this clean energy produced during the day offsets the grid power needed after the sun goes down. The next prototype planned is to be much larger, with more solar collectors and a 100 horsepower motor, producing about 73 kw. Once that goal has been achieved, the company is looking at building a 1MW operational solar steam engine power plant.

[spinningmagnets]

For solar thermal, he definitely NEEDS to switch to Organic-Rankine-Cycle (ORC) think of it as "freon steam". the equipment is almost identical.

Its been done before, it works. Using the classic water-steam plant (whether piston or turbine) will add exponentially to the size and expense of the plant per a given output.

[MitchJi]

Hi,

http://www.zenmanenergy.org/#zenmanstory

The First Prototype

The first prototype will turn a 10 horsepower motor, roughly 7.3 kilowatts of energy. It will produce more than enough energy to offset a single, high energy usage, American home. In the grand scheme of things, this is tiny, but it is large enough to prove the design works; giving us a starting point to expand to larger sizes. Obviously solar power does not operate when the sun goes down in the evening. Think of this as an 'offset' instead of getting off the electric grid. 7 KW would provide enough energy to power 3-4 homes at any given time, but once the sun goes down it no longer produces energy. That's ok with us, as we can plug into the electric grid and the transmission lines will automatically route the electricity to where it is needed. An average American home uses roughly 29 KWH per day. Our goal is 5 hours of sunlight per day producing roughly 35 KWH per day. By using the grid, it doesn't matter to us which buildings actually use the electricity. But this prototype is enough to offset one high usage home.

[MitchJi]

Hi,

For solar thermal, he definitely NEEDS to switch to Organic-Rankine-Cycle (ORC) think of it as "freon steam". the equipment is almost identical.

Its been done before, it works. Using the classic water-steam plant (whether piston or turbine) will add exponentially to the size and expense of the plant per a given output.

Suggest this to them (or contribute a prototype)?
http://www.zenmanenergy.org/#zenmanstory

Getting involved in designing the prototypes

Are you an engineer? A hobbyist maker? We DEFINITELY need your help to get this project off the ground! Over the next few months we'll make a way for people around the world to contribute and test designs to improve the prototypes, remotely. But we need help from others too! Right now, the MOST critical thing we need is funding! We don't need much, but we need to custom machine certain parts which is not a cheap endeavor. You have a few spare dollars in your pocket, donate it to a good cause.

[Samd]

Would ORC compare on a dollar per watt basis with a steam unit (or stirling) using low cost china sourced parts?

Does ORC have any barriers to entry for the hobbyist - is there a working fluid that is hard to source?

[spinningmagnets]

A friend who is an engineer crunched the numbers a while back, the solar collector for water-steam has to be very VERY large. You can make a pot of water boil pretty fast, but once you recycle the condensate, and re-introduce it to your boiler, the water stops boiling for a short while. The condensate should be around 180F-200F.

ORC has been done with Freon (Di-chloro-di-fluoro-methane, or tri-chloro-tri-fluoro-ethane), also Butane, Propane & Toluene (all three flammable, but they work).

High voltage AC is needed to make the kind of electricity that you can ship long distances over wire. Then when it reaches its destination, it is lowered by local transformers. It is cost-effective to make a large central generation plant using large expensive equipment, and distribute it over a wide area. For local generation, you can go with a lower voltage (220 VAC?), which can be made by lower RPMs on the turbine, which can be generated by a lower pressure differential, which can be done by smaller less-expensive equipment.

Research the Chena Hot Springs in Alaska. Its an isolated resort where all the electricity came from a bank of diesel engines that had their fuel brought in by ship in the summer. They had a natural source of hot water that was easily accessible (provided heat 24-hrs/day), and also the air-temps were cool, even in the summer. They installed an ORC system that is very successful. Much of the equipment is simply modified air-conditioning equipment (the large kind that would cool a large building). http://www.yourownpower.com/Power/

Air-cooling with warm air, cuts the power potential, but it will still work. using solar concentrated heat would work just fine. An example of this is an MIT pilot project in Lesotho/Africa http://web.mit.edu/newsoffice/2006/lesotho.html

Stirling? they are a favorite of mine, but...they are a big engine for a small power output. Here's the "Jim Dandy #6", 2-1/2 HP = 1800-watts. It could be converted to solar heat. Problem is they only generate when the sun is shining, and batteries are expensive (and they wear out).
http://www.starspin.com/stirlings/jimd6.html

[Dauntless]

Hey, Mr. Magnets, don't stop now. I want to hear more of this.

Freon has got to be out of the question. Are these other gases as effective? What about the EPA freon alternatives? http://www.epa.gov/ozone/snap/refrigera ... omeac.html Or am I just too caught up in the notion of mass production?

Isn't there SOMETHING to replace that Stirling engine? Those things just keep failing efforts to develop new uses.