Invention using HydroElectricity? What do you guys think?

I think that was cool! And probably a good solution for places with strong currents (fjords with big tidal changes). They might have a problem when the tide turns... Check out this company doing some of the same: Flumill AS - Home

However, for places where hydropower is available with mountains and a lot of rain (like Norway) I don't think anything can beat traditional hydropower with dams and turbines

Electricity in British Columbia is 94% from hydroelectric sources. Lots of rain, rivers and mountains here. The majority of the remaining 6% is natural gas.

I actually did a bit of work on Tidal Power during my undergrad (Civil Engineering) as my alma mater is located very close to the highest tide differential in the world - the Bay of Fundy which can have a tide ranges between 14-16m. Here's a few takeaway points I discovered in my prelimianry research;

1. The applications are pretty location specific. Lower tide differentials = less ebb/flow speed which requires a different type of turbine to properly optimize the water. Due to the nature tide cycle, you get a number of idle periods throughout the day where the water does nothing, much like wind turbines, but in much more predictable cycles. Tidal power will never be able to act as more than a supplemental energy source because of this. When you also factor in neap tides, the reliability of constant power really starts to fall off.
2. There's a lot of competing technologies around the world from what are essentially underwater wind turbines to the waterotor design you linked and all sorts in between. There is no clear winner as far as I know as per point 1.
3. Their are some environmental concerns about installing a bunch of turbines all over the fjords and inlets of the world. Not that these have a terrible big footprint, and they certainly don't spin nearly as fast, given that water is approximately 832 times as dense as air. Not likely to affect fish or whales, but could cause problems for fisherman or any other industry that relies on the ocean being free of bottom obstructions.
4. Serviceability can be tricky depending on the design. Stuff tends to grow on things underwater. That can really affect the blade efficiency not to mention escalate costs if you need to haul the thing up every few years for a full cleaning.

I was disheartened by these findings as I thought it was a really cool environmentally friendly technology, but I can't see it being much more of a boutique power source for those who have the extremely unique geogrpahical/oceanic conditions that make this technology work.

Going to find that thread on solar roadways... as somebody who's personally overseen the construction of several major highways, I have a lot to say about why I think this is a bad idea.

In NYC here, they are experimenting with installing tidal power:

Turbines Off NYC East River Will Provide Power to 9,500 Residents | Department of Energy


As far as solar roadways go, silly idea. I mean lets use some common sense here for a second, power generation is based on cost.

It is not like we are lacking in places to put solar panels, it is not an issue of running out of space, it is a factor of cost. And solar panels places in ideal locations where they are tilted at an angle with most sunlight exposure would gain more benefits. And it is most likely far more expensive than putting in asphalt.

So solar roadways don't really work from a cost perspective or efficiency perspective.

Calling Robert.Boston......

Hehe, thanks for the cue, Audie. For those who haven't realized it, I run the commercial side of an ocean-wave energy company. So I'm very bullish on using moving water to produce power.

To help the discussion, there are five categories of water-based generation:

1. Traditional hydro: dam-across-a-river a la Hoover Dam. This is a mature technology and represents nearly all of the hydro-power production.
2. Pumped storage: a variant of traditional hydro, where the generator turbines can be reversed to pump water back up into the reservoir.
3. Tidal: uses the fact that tides create a "head" between the high- and low-tide mark
4. Current: uses the flow of water to generate power. Note that many installations in tidal zones are actually using the current, not the head; such generators have to be able to flip around or use bi-directional input.
5. Wave: uses the action of ocean swells to generate power. See, e.g. Ocean Power Technology or Pelamis.

The invention you provided the link to is in #4. I'd like to see the calculations of how they get to 5 cents/kWh; in particular, have they included in that number all the maintenance, licensing, installation, interconnection, and taxes? Regardless, even if that's low by a factor of two, it's a good number.

I am not an engineer, but I don't see anything about their technology that strikes me as fishy (pun intended). I like several elements of the design, including the general robustness of the structures, the use of flexible mooring cables (instead of fixed mounts), and simplicity of design. Presumably they have data regarding interaction with riverine fauna, and they've figured out how to deploy these in navigable rivers. If would want to know how they deal with currents above the rated speed (if that's a potential issue during, say, spring flooding), and how survivable the device is after impact with large objects e.g. tree trunks, boats that have slipped mooring.

On the whole, though, I think this is a promising technology that could tap an under-used resource.