Wave power that actually works?

[begreen]

There have been a lot of attempts to create power from ocean waves. Many have failed, often due to parts corrosion or breakdown. Wave Swell has a 200 kW prototype that has completed 12-month duty cycle. Its main difference is that there are no moving parts in the water. Wave Swell CEO Paul Geason said that the generator had achieved conversion rates of 48 percent. This means that out of the total energy brought in by waves, the generator supplied 48 percent of that to the grid. "That rate is very encouraging and, in fact, is higher than other renewable energy technologies," Geason added. So far there has been no negative impact on local marine life.

Now they are evaluating the results and looking at ways to improve efficiency and scale while reducing costs. It's an interesting approach and it could be liberating for island nations dependent on fossil fuels.

According to the U.S. Energy Information Administration (EIA), the annual energy potential of waves off the coast of the U.S. is 2.64 trillion kilowatt-hours, roughly 66 percent of the country's annual power generation. Tapping this energy is sort of a holy grail for renewable energy considering many major cities in the US are coastal but the challenges to come up with a durable cost-effective design are not trivial.

Uniwave®​

The Wave Swell Energy (WSE) technology is based on the well-established concept of the oscillating water column (OWC).​

The OWC is an artificial blowhole consisting of a chamber that is open underneath the waterline. As waves pass the OWC, the water rises and falls inside, forcing the air to pass by a turbine at the top of the chamber. This turbine generates electricity.

Previous OWC technologies have all been bidirectional. The WSE technology, however, operates unidirectionally. This results in the WSE turbine being simpler, more robust and reliable, and exhibiting a higher energy conversion efficiency. The only moving parts in the technology are the turbine and bespoke valves, all of which are well above the water line. There are no moving parts in or below the water.

September 2022 - WSE

www.waveswell.com

 

[EatenByLimestone]

They might be able to work on the Great lakes too. That’d open up the Midwest to wave generation.

 

[woodgeek]

I skimmed the video, but missed any mention of total power output of the test unit, or its cost per watt or watt.hr.

This is IMHO a big red flag.

 

[Ashful]

I'm skeptical of wave power ever really scaling. Tidal power, sure! Haulover inlet, anyone? But waves?

Waves are created by wind, localized phenomenon. We can already harness wind power via turbines. Injecting the "middle man" that is ocean water seems to be adding a lot of unnecessary challenges, WRT salt water corrosion, sand, freezing, and marine biology. Barnacles, anyone?

Tidal power is something we cannot already harness by other means, making the costs and challenges facing a marine environment more justifiable. Perhaps innovations in one can drive the other, but I'd not be putting my money on wave power as a leading contender.

 

[SpaceBus]

I'm skeptical of wave power ever really scaling. Tidal power, sure! Haulover inlet, anyone? But waves?

Waves are created by wind, localized phenomenon. We can already harness wind power via turbines. Injecting the "middle man" that is ocean water seems to be adding a lot of unnecessary challenges, WRT salt water corrosion, sand, freezing, and marine biology. Barnacles, anyone?

Tidal power is something we cannot already harness by other means, making the costs and challenges facing a marine environment more justifiable. Perhaps innovations in one can drive the other, but I'd not be putting my money on wave power as a leading contender.

Tidal power has been harnessed before, which I only recently learned. Apparently tide mills were a big thing in some areas with poor river resources.

 

[Ashful]

Tidal power has been harnessed before, which I only recently learned. Apparently tide mills were a big thing in some areas with poor river resources.

Exactly my point. They become very dependent on location, but given high population density generally follows water, I don't think this is bad. I suspect the primary challenge here is doing it without interfering with busy high-use inlets, as that's where energy density (by velocity) will be highest.

 

[begreen]

I skimmed the video, but missed any mention of total power output of the test unit, or its cost per watt or watt.hr.

This is IMHO a big red flag.

I read 200 kWh on the site. The cost per kWh has to be huge due to this being a one-off, prototype. It is a university level test bed. The next step is to evaluate the system degradation over a year and analyzer performance. Evidently it stood up and performed well in this hostile enviornment. At this point they are saying that much was learned and they expect to be able to significantly improve efficiency. Mass production would drop costs. Whether this all pencils out in the end is TBD, but the prototype's performance is encouraging.

 

[woodgeek]

I'm not asking for the actual cost of building the prototype, I'm asking for the projected cost of the units in mass production.

This is the sort of thing we ask our engineering students to do all the time... to estimate the cost of a process or a device in mass production from the cost of the parts and materials, and well known multiplier factors of those numbers for assembly, design, inventory, shipping etc.

If they built one, they can tell you how much it would cost to mass produce 1000 identical ones.

Beyond that, they can design bigger units (that are presumably more cost effective) and try to find a $$/kWh for those units in mass production.

I am certain that a project of this scale has done those estimates. The fact that they are not being reported means the outcome is no bueno.

Solar is stupid cheap (in areas with a decent resource). Batteries are getting there. Coal can't compete in those areas on price. Is this wave tech cheaper than coal on a $$/kWh basis? Show me some numbers.

 

[begreen]

I'm not asking for the actual cost of building the prototype, I'm asking for the projected cost of the units in mass production.

The production output and cost areTBD after full analysis of the prototype which just started a few months ago. The CEO talks about several lessons learned and alterations being planned to increase efficiency and commercial level reliability. The next project focus is building an array into a seawall.

The benefit of this method of power production is that it's 24/7 unlike wind and solar. The target market appears to be remote islands in the Pacific where price per/kWh is high due fuel and maintenance costs for diesel fired generators.

Show me some numbers.

Write them.