Ocean Thermal Energy Conversion plant

[MarkP]

I have to be open here as I am not up on the latest details but I think there is ample room for misunderstanding. I don't think that there is much wiggle room to overlap uses. Air conditioning typically employs chilled water with a low temperature in the mid 40's and a high in the mid 50's. Above that the air is not cooled sufficiently to properly condense and control humidity in the conditioned space. That's a delta T of about 10 degrees F. Chilling water into the mid 30's and employing a larger delta T of 20 degrees F works great and is sometimes done but it gets disproportionately more expensive to "make" chilled water that cold, so the 10 degree spread represents sort of a sweet spot in terms of cost. The deep ocean water we are talking about is in the mid 30's so it represents a great fit, but when you are done cooling a building with it there won't be much cold left in it in a way that is useful for further chilling or power generation.

Generating power is a whole 'nuther story. The 40 degree spread from mid 30's to mid 70's is abysmally low to drive any sort of heat engine. It is a huge challenge to generate power using the whole delta T. Hoping to use spent water to chill buildings is like hoping to tow a 5th wheel RV with a prius. There might be some application for chilling garden soil.

I think that by "byproduct" they mean that they installed the pipe already and since they are really not doing too much OTEC with the water, it is available to use for other things.