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Comment by aljungberg | Hacker News Reader

One wonders how quickly these pores will become clogged over time. If the membrane deteriorates fast, the energy cost of producing more membranes continuously needs to be factored in.

The article headline is pretty weird, by the way. So this technology can generate “thousands of nuclear power plants worth of energy”? But then in the third paragraph it sounds like they mean to say if you installed this membrane in every estuary in the world, then it’d beat 2000 nuclear plants.

It’s like saying there’s more water in a cup than in a bathtub, as long as the cup is the size of a car.

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It's too bad RO is still so inefficient, or you could store purified water with surplus grid power as a cogeneration strategy. Drinking water or power, depending on which is in shorter supply.

I suspect that pumped storage is rather more energy-dense than this. I suppose both could be combined.

the researchers estimated a single square meter of the membrane [...] could [...] power more than 400 homes.

Three homes. Please update your comment.

*Correction, 6 December, 11:30 a.m.: This article has been corrected to accurately reflect how many homes a blue membrane could power and how much energy per area it produces.

Either the power or the number of homes in the article is completely wrong. 30MWH/year powering 400 homes is 8.6 watts per home. Implausibly low, unless "homes" is a typo for "phones".

Even the smallest nuclear power plant in the states generates 582 MW — enough for 95 000 homes.

I’m not saying this isn’t a cool membrane. I’m making the point here that the comparison to 2000 nuclear power plants seems arbitrary.

.. or in real units, 30MWH/year = 3.425 kW. Which is quite a lot. That's what I get from about 10 square meters of solar panels, or one electric kettle running continuously. Seems implausibly high, I would move the decimal point over by one and naively guess it has the same energy density as solar panels.

That is really high. However I think you could run a few kettles off this. In the US most tea kettles are 1-1.5kW, as are other high power appliances like microwaves, hair dryers, vacuum cleaners etc. 15A circuit breakers are common for general purpose home power outlets which max out at 1.6kW. I think the NEC recommends 2 20A circuits to supply kitchen's non-dedicated power outlets.

Kettles in the US are underpowered and slow. 3kW is pretty normal for a kettle in Europe as everything runs at 230V.

It isn't the voltage that improves the time, though, it's the power. So are you saying that wiring in Europe uses the same or better circuit breakers (e.g. 15A or 20A) at the higher voltage, thus providing more power? Or that the wires in European homes are of equivalent gauge to wiring in US homes, but due to the higher voltage, can therefore carry more power?

Both in UK. 32A ring mains at 240V powering sockets up to 13A each. https://www.tlc-direct.co.uk/Book/6.3.3.htm

Running multiple kitchen appliances at once without tripping a breaker is a convenience I miss now living in the US.

AFAIK, in Europe you find either 10A (2300 W) on older installations, or 16A (3680 W) on newer installations. This is for your regular wall sockets.

Then you can get bigger stuff for your garage etc, you have 230V three phase in either 16A or 32A (blue connectors, physically incompatible across amperages) as well as 400V three phase in 16A and 32A (red connectors, again foolproof), i.e. 22 kW max power, generally only available if you have a new-ish house and you're running some sort of industrial equipment.

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