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Comment by tinco | Hacker News Reader

Nice, that's a cool scenario I hadn't thought of. I haven't heard of any deep sea wind generators, but obviously that might have great yields. I wonder if that far out at sea it wouldn't be easier/more feasible to have solar panels instead of wind mills.

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Using [1] temperature difference between deep water and surface water may be even more efficient

[1] https://en.m.wikipedia.org/wiki/Ocean_thermal_energy_convers...

You can bypass the heat engine, and just condense humidity onto coils with cold deep water running through them. You only need an insulated pipe to bring the deep water up through. The more water you move, the less insulation you need.

Offshore wind is proven tech at this point, to the point that there are commercial offshore wind farms that have been built without any subsidies. Mainly in Europe but starting also in the US. There is no major R&D necessary to make it happen, just scaling and cost engineering.

The Biden administration target for 2030 is to have 30 GW installed generation capacity in offshore wind.

Yeah but none so far away that you couldn't just lay a cable to transmit the power to the shore.

> Offshore wind is proven tech at this point

Shallow water only. The North Sea is perfect, the east coast of the US looks good in places. Deep water is unproven currently and in the R&D stage with no known economically viable solutions.

Major construction projects are ongoing, based on already proven solutions.

Bullshit. Best so far is Hywind, which is 3x the cost per MWh of shallow offshore.

There is also https://en.wikipedia.org/wiki/Wave_power

Tidal turbines are a good contender. The tides are constant.

As someone who has spent a fair bit of time in / around salt water I’m skeptical of these claims. I want to see all in deployment costs with maintenance. Are these deep water or do they need to be shallow water where they will be banged up even more in storms etc

I don't know about tidal forces, I do know in the Netherlands they create energy from salt / fresh water dialysis. https://redstack.nl/en/

Tidal turbines are viable in inlets where currents are consistently strong during tidal changes, the problem is they often disrupt the ecosystems around where fish need to spawn. Altering the total water flow into estuaries is sketchy and the good places are typically shipping lanes. You could put them in a place like Gibraltar and live with reduced water exchange in the Mediterranean, but it will be met with a lot of resistance.

Ideas that rely on moving a mass up and down 10 feet every 6 hours require floating platforms the size of Rhode Island. Not cheap to build.

Neither strategy is a contender in my book. I recall a research project in France which the results were unappealing. The environmental costs were high and power generated was low. You have to be careful getting scientific knowledge from the mainstream press or researchers who need to sell their research which means it is more akin to marketing than scientific knowledge.

Attempts at tidal power extraction in the Bay of Fundy have failed because the turbines broke, every time.

Attaching a simple float to a cable and pulley turning a generator onshore seems not to have occurred to them.

Numerous (i.e. all) wave energy startups have likewise gone bust trying to keep machinery working exposed to maritime weather. It seems never to occur to them to keep the stuff that would need attention onshore and indoors.

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