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Comment by hannob | Hacker News Reader

There was actually already a test osmosis power plant in Norway. Unfortunately it wasn't very successful and was shut down in 2013: http://www.statkraft.com/media/news/News-archive/2013/Statkr...

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If the membranes are anything like those in watermakers on yachts, they're pricey and gunk up easily.

The output per sq meter at 12.6W seems rather low compared to solar cells at 150-200 W/ sq meter when sunny. It's probably going to be easier to stick up a solar panel than a membrane contraption several times bigger.

The benefit of osmotic power/salinity gradient power is that it's a base load. That means it will produce power at a constant rate, regardless of the time of day, which is one of the draw backs of the more common sources of renewable sources of energy (solar, wind, etc.)

Base load is not necessarily an advantage in a future energy system. Lots of solar and wind means there will be times when all the electricity can be provided by them. So what's really needed is flexible electricity to complement that.

At that point, it's free energy. Are you really complaining?

(Yes, I do know power companies must dissipate that somehow, my own even has times whence the realtime pricing drops below zero as incentive. But a solved problem nevertheless.)

It's not not free if your power plant is free, too.

The extra energy can be dumped into pumping water up a dam. It is reasonably efficient, at 70-80%.

https://en.m.wikipedia.org/wiki/Pumped-storage_hydroelectric...

Yes, but excess solar, wind and nuclear can already do that. So introducing a new, so-called "baseload" power supplier doesn't automatically make for good economics, if anything selling it as "baseload" rather than say "cheap" is a bad sign.

Another case of the lab/field gap. So many things that work well in the lab are just terrible in the field.

In energy in particular, it seems like a good idea to increase the ratio of field to lab research.

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