World's First Osmotic Power Plant Goes Live in Norway

I just hope that the Salt and the sea water combine back together in a natual way. when there is a salt imbalance in the oceans bad things tend to happen.

How exactly are they mixing up the salt water? Would seem they would need to keep adding fresh water to it....and I think fresh water isn't something there is an infinite supply of.

4KW coffee maker? That must be one serious coffee maker! That equates to a 5.333 horsepower coffee machine!

My entire house uses less than 4 KW (typically between 2 and 2 KW)! I think a better comparison would be it is enough power to run a house - slightly more accurate.

I've been following the building of this and it really is a marvel in the electric production industry. Congrats to the Norwegians.

P.S. If you are not gonna take time to read the original article please don't comment.

Sea water and fresh water are naturally mixed where any river meets the sea - it's not a 'waste', and there is effectively an infinite supply (especially in rainy northern Europe)

Sounds like a wonderful idea! One more blow against Climate Change! This article should be expanded further, however. I would like to know how the present miniscule output can be scaled up to powerplant levels. Doesn't significant energy need to be expended to power the osmosis process in the first place? 4 kw is the net output?

"One quick solution: implement osmotic plants near desalination facilities, which produce a briny water twice as salty as seawater as a byproduct."

Desalination plants are used to produce fresh water. This power plant consumes fresh water. This is going to result in a net loss of energy. Bad idea.

4KW is more than enough to power a typical suburban home. This is the second post I've read of this where the author is making a slight mockery of the technology.

I don't get it! Are these writers technical or scientists in any way at all???

Here's what you can run with 4KW (4000 Watts) of electricity:

- 5 light bulbs (100W each) = 500W
- Big microwave = 1000W
- Medium sized AC unit = 1000W
- 2 Ceiling fans = 50W
- Big gaming computer = 450W
- Fidge = 500W
- Watching movie on home theater = 500W
TOTAL = 4000W

And that's if you had all these running at the same time, but why on earth would you need to run all that at once?

Blaxpear:

Agreed!

I actually would put the lighting requirements down to around 100 watts with compact fluorescent quickly becoming the new standard (that could be five 20 watt bulbs). That would free about as much power as you would need to run a more typical coffee machine then the so-called author has.

I think incandescent lights are either illegal or soon to be illegal.

Note too that microwaves, refrigerators and AC units typically run intermittently most of the time - which is taking up 2500 watts (more than half) of your list.

Also most AC units are only used seasonally.

I find it hard to believe this is economically viable for anything other than outside a desalination plant. Just moving the seawater into the facility would take a lot of power. A desalination plant is already moving the water for other purposes so it's not extra costs.

If you had a situation where there's a sewage plant dumping their treated water into the ocean, then you have two sources of water that can be moved around without much extra energy input. But then the real estate is pretty valuable so it's hard to imagine a large enough plant being built to be worth it.

bagpipes, my understanding would be that once an initial amount of fresh water has been added, the filtered sea water would substitute it and just keep the cycle going.

Sounds like they would be better off making seasalt as a product and electricity as a by-product.

This is an informative article. Thanks for sharing it.

I think it's a valid idea, but maybe not too practical.

Economic Issues:
1. In developing countries, the amount of freshwater available would be the limiting factor.
2. In developed countries, the amount of available land near where a major freshwater source meets a saltwater source would be an issue- these tend to be areas of high land value.

Environmental Issues:
1. Areas where freshwater mingles and joins with salt water are important ecologically as fish breeding and feeding areas (estuaries).
2. Diverting enough fresh water from a waterway to generate electricity may block anadromous fish migration, similar to hydro dams.

Other thoughts:
1. Many of the environmental and economic concerns are significantly less if the system is using wastewater discharge. Where treated wastewater is released into the ocean, there may be ample supply of both fresh and salt water. The issue then becomes this: couldn't we save more energy and have less environmental impact by simply taking the treated wastewater (which is generally cleaner than the water it is being discharged into) and filtering it a bit more to recycle right back into the drinking water system?
2. This does hold some promise for near desalinization plants, but not by using the desalinated water- as pointed out, that would give no net energy production. Instead, since the process relies simply on the osmotic difference, use the seawater as the "freshwater" and the brine solution waste from the desalinization as the "saltwater." It seems that there would still be enough of an osmotic gradient between these two water sources to re-harness at least some of the energy used by the desalinization plant.

A thought:
Considering my last point, it seems to me that this technology may have its greatest impact by reducing the amount of energy required to run a desalinization plant.

"How exactly are they mixing up the salt water?"

Osmosis is similar to reverse osmosis, but in reverse... err, yeah...

"Would seem they would need to keep adding fresh water to it....and I think fresh water isn't something there is an infinite supply of."

There are these things called rivers. They transport, oh, a couple of thousand cubic metres per second of fresh water into the ocean that we don't know what to do with; it's the same with Sweden and Holland.

What's the alternative? A hideously uneconomical fresh-water pipeline to Spain?