Solar Electric Power Plants

I am not familiar with this type of solar plant but from a quick check on the internet (http://en.wikipedia.org/wiki/Solar_pond), its output seems to be heat. It looks similar to a geothermal plant, but at first glance I cannot see it producing enough heat to be particularly useful (60 degree C temp change is just too small) and its efficiency is only 15%.

I look forward to learning something new from this thread from someone with more understanding on the advantages and disadvantages of "solar ponds".

Anyone looking at schemes to recover useful energy from heated ponds, waves etc, needs to be familiar with the Carnot cycle and Carnot efficiency. It shows that efficiency drops when the temp difference is small. Jeff

You are totaly right but there are situations -especially when energy does not cost - where efficiency is secondary. It was a very inetersting discussion related to stirling motors wher such aspects have been discussed. In the case of solar energy in remote places an even low efficiency approach could help. The only problem is to find a way with a reasonable cost for investment.

OK. Sometimes low efficience emissionless solar power plant, day and night, would be better than 33% Carnot efficience, only as a theorical target, but sure, with higher regular costs of natural gas, diesel oil, or coal. I have a new question: Would we get 92°C ( 198°F ) for 24 hours/day from a solar pond, in local places with 600 W/m² average solar energy during 8 hours day? We would like to talk about this kind of heat source equipment. I hope new solar pond designs, sure with modern impermeables and thermo insulating plastics materials.

There is a major problem where there is a lot of sun there is no water and vice versa. So that the pond as a collector can be interesting but it is a problem to maintain the water and compensate possible losses. There are other solutions for energy collectors i cannot say which one is optimal but with todays interest a progress is to be expected.

SFIK, once the temperature differential becomes small, the size of an engine for a given power grows approximately as the inverse square of the temperature differential. If someone knows of engine designs that don't suffer from this, please post a link.

If that is correct, unless you can build the engine itself of almost free locally available material, the small temperature differential would likely make the cost of the engine itself prohibitive?

It ís wise to exchange the work fluid to have "normal" size machines. I mean a Kalina Cycle ( water + ammonia ), butanne thermodynamics cycles, ou even a gas called by "green freon", i hope so. With a few time for R & D, and capital for news investments of course, we can think over four differents alternative researches: Positive displacements motors, Tesla turbine ( please sea google ), stirling motor, and a water ring insulated pump working in a reverse way. Fernando

My understanding was that this relationship tended to be optimistic, and applied to all kinds of engines - due to the combination of limited proportionate pressure differential and limited fluid velocities.

Anyone know different?