Different Approach

[Mark Parsons]

Stumbled across this new technology to harvest electricity from Solar. Claims $0.01 per kWh cost. I like the price...

http://www.ergenics.com/page27.htm

Hydride heat engine. Should also be good for harvesting geothermal electricity from hot springs.

Looks promising.

[Renic Gunderson]

That looks like a very interesting heat engine. I wonder how they plan to keep the cold water cool.

[Mark Parsons]

Greetings Renic,

The warmed cold water could keep a greenhouse warm in winter, heat a house(s), or drive an absorption refrigeration system for cooling a house, plus many other useful options. Least useful is an evaporative chiller dumping the heat to atmosphere.

The bigger question is:
Is this method robust and cost competitive? If so, lets get a pilot plant up and running.

A quick look at the Ergenics web site doesn't reveal any new info since March.

Regards,
Mark

[Renic Gunderson]

The warmed cold water could keep a greenhouse warm in winter, heat a house(s), or drive an absorption refrigeration system for cooling a house, plus many other useful options.

yes, but then wouldn't you need a constant supply of cool water?

would the amount of energy required to move the water for such uses require more energy than the generator provides?

[Rob Beckers]

It sounds like hydrogen is cycled between gas and 'bound' state (in a hydride, ie. bound to a metal). So, they would have to recharge the hydride after cycling it out through heat. How are they planning to make this a continuous cycle, rather than 'produce energy', 'recharge', 'produce energy', 'recharge'... I'll admit I'm a bit fuzzy on how this works, maybe someone can explain.

-RoB-

[Mark Parsons]

My understanding of this hydride is that hydrogen is driven off over 50C and absorbed under 20C.

Water temp above 50C drives the gas from the hot hydride cell through the turbine and into the cool hydride cell when below 20C. This process dumps some heat in the cool cell. Once the 'hot' hydride has depleted its gas, the cells need to switch tanks to drive out the gas collected in the cool cell. The gas is driven from hot cell to cool cell in a closed loop.

I suspect that this cycle is not 100% regenerative and over thousands of cycles the hydride loses some of its ability to absorb the gas. More info would be beneficial.

To speculate on answers to Renic's questions;
yes, but then wouldn't you need a constant supply of cool water?
The cool cell would warm the water from the hydride action. This water would need to be recirculated through heat exchangers to dump this heat and keep it under 20C for the hydride absorbing action. The hot cell could be warmed from solar hot water panels or geothermal source.

would the amount of energy required to move the water for such uses require more energy than the generator provides?
All a matter of scale and design. It doesn't take much energy to recirculate water.

Regards,
Mark