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The Stirling engine coming of age?

motion guru

Diamond
Joined
Dec 8, 2003
Location
Yacolt, WA
I visited a plant this week that was building sterling engine powered power plants. Infinia Corp.

It was an interesting integration of solar and inverter technology.

I saw at least 3 applications sitting on the floor - and they had several solar power plants producing power outside.

One application was burning natural gas to power the generator with the waste heat used to heat the home. The claim was 95% + conversion of the energy from the gas to electricity + home heating + water heating. It installs like a furnace but also provides the energy to run the furnace fans and heat the water and sell energy back to the utility.

Another was a diesel fired unit that made hot water and electricity for field military deployments.

Lastly was actual solar generator.

The plants were quiet and had a mechanical design life of 25 years and were basically sealed units with the motors filled with helium as the working fluid.

They job everything out and only do final assembly of components. The parts are designed for manufacturing - the reflective mirrors are stamped much like an automotive body panel and then coated with a metalized mirrored adhesive film.

Local article on the company behind this

They have a small 150kW installation in Spain running now - and test systems running in a few installations in the US. This is one of the few technologies that looks like it might actually make sense from an energy balance stand point and it employs traditional manufacturing capacity that is already in place.
 
I have often thought this is the way to go and it is nice to see something happening. I hope it is a 'real' something and not just a bunch of fastbuck artists building something up to blow off in a stock offering.

I remember reading somewhere about a solar/Stirling system that was built in California a number of years ago that had an overall efficiency from sunshine to electricity of 35%. That sounds high, I wonder if my memory is being too optimistic; I know it was mentioned that it was significantly better than photovoltaic conversion.

The other thing with the Stirling approach is that phase change salts can be used for storing the heat to use either at night or during brief cloudy periods and this can be more efficient than storing the electricity. Phase changes give you back all the energy that went in but batteries being chemical reactions cannot be 100% efficient.
 
There is an interesting corollary to solar radiation and that is night sky radiation. The night sky has a temperature of -70º. Entropy being what it is, clear dry night skies are capable of exchanging a lot of watts by radiation out in to space. What this means is a simple night sky radiator (Google it) can produce a lot of water that is colder than ambient air. I've seen estimates of 500 watts per meter squared which is just over a third of the energy that arrives from the sun for the same area.

Since Stirling motors and similar motors work by temperature differential, this is a cheap way to use even more of the energy collected during the day. An obvious configuration would be a cooled tank of water and a heated tank of water driving the motor.

Here's an application of night sky cooling:

http://www.cedarmountainsolar.com/nightskyradiantcooling.php?PageID=5

And if you happen to have a global warming bias, this is as green as energy gets - it is radiated out into space, never to be seen again.
 
Motion, thanks for posting this. You must have been in town for the SmartMap Manufacturing Expo?

I worked at Infinia for 6 years before starting my shop. It's remarkable to see the transformation that has taken place since Y2K. From an R&D company with as low as 12 employees when I started, to the 100+ that are there now focusing on a viable commercial product. They are leaders in their industry and are at the forefront of helping shed the idea that Stirling engines are just inefficient toys.

While the 3kW solar units are grabbing the "headlines", I'm personally more excited by the Combined Heating and Power (CHP) potential. Everyone could take advantage of these in their home. Infinia has partnered with Enatec from The Netherlands and Rinnai of Japan to produce these for home use. Rinnai, being one of the largest appliance makers in Asia should provide some muscle to get this accomplished.

Maybe they didn't bring it up, but they also have a cryogenic cooler project on the floor as well. "Cool" stuff...

Look me up next time you're in town. My place is not as exciting as Infina, but I love to have visitors.
 
.....I worked at Infinia for 6 years before starting my shop. It's remarkable to see the transformation that has taken place since Y2K. From an R&D company with as low as 12 employees when I started, to the 100+ that are there now focusing on a viable commercial product. They are leaders in their industry and are at the forefront of helping shed the idea that Stirling engines are just inefficient toys.....

Oh good, my cynical pessimism was misplaced.

I developed that attitude from back in the early 1980s when I was invited by two or three startups to get on board because I could give them technical credibility and academic credibility so they could puff things up on the stock market.
 
Oh good, my cynical pessimism was misplaced.

I developed that attitude from back in the early 1980s when I was invited by two or three startups to get on board because I could give them technical credibility and academic credibility so they could puff things up on the stock market.

A lot of employees thought exactly that when the current CEO was hired. Luckily every employee had a chance to voice their opinion about the direction they wanted the company to go. Overwhelmingly, the consensus was to keep the company "as it was" and not to sell it or go public. That was 7 years ago, and the promise has been kept. I will say that the CEO is a master when it comes to raising capital, which has enabled the push to commercialization.
 
It’s heartening to hear of a CEO who can look at the long term rather than just next quarters’ P&L statement. If we had more of these, US business and industry would not be in the current mess.
 
Motion, thanks for posting this. You must have been in town for the SmartMap Manufacturing Expo?

Look me up next time you're in town. My place is not as exciting as Infina, but I love to have visitors.

hesstool - yes I was at the show and we had a booth there. We brought our MS Mouse testing machine and it was great draw to get people into the booth.

I agree that the in-home unit for heat / hot water / electricity looks to be a great product.

The generator is the perfect blend of mechanical, electrical and software integration - and the company did a great job of showing off the facility, telling their story and generally being great hosts.
 
It’s heartening to hear of a CEO who can look at the long term rather than just next quarters’ P&L statement. If we had more of these, US business and industry would not be in the current mess.
Isn't that the truth.

Public ownership of corporations and quarterly P&L statements and can destroy any industry.

- Leigh
 
And if you happen to have a global warming bias, this is as green as energy gets - it is radiated out into space, never to be seen again.

Hole Mackerel Batman, goodbye global warming, the dawning of a new age: the warming of interplanetary space!
 








 
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