Vertical turbines are more efficient in large-scale wind farms: study

The big problem is resonances. A VAWT has various modes of resonance that are very hard to engineer against due to some of their basic properties. The largest of these, the one at Cap Chat in Quebec ended up being scrapped after an embarrassingly short period of operation.

There are some VAWTs in the rockies that lived for more than a decade but they made really little power compared to the amount of money that went into them.

But they look nice and are deceptively simple on paper (one less parameter to deal with due to the fact that you don't need to steer them, and the generator stays at ground level). So likely people will keep trying but it almost certainly isn't going to move the needle in the longer term.

Regarding the risk - I don't think this characterization is doing the issue justice. It's really about decades of building up a manufacturing capacity with suppliers, etc. to get to a position where wind turbines are now competitive because of this manufacturing capacity.

For an alternative to develop, it is not enough that it is slightly better. And both turbines driven by kites and vertical turbines are known tech, with known problems. They are likely not slightly better. Early wind pioneers knew about vertical turbines. They have some nice properties. But also some not so nice ones.

And this paper does not study vertical vs. horizontal as far as I can tell from a cursory look. It studies what happens with vertical turbines in a small farm.

That reminds me of that recent finding that wind turbines would be a few percent more efficient if they turned anti clock-wise (at least on the northern hemisphere), but practically turbines in use today turn clock-wise. Sure, it should not be to much engineering to change that but still you need to adopt the entire manifacturing process to it.

Tangentially, I ran into the bladeless vortex concept recently (https://vortexbladeless.com/), do you have a take on that?

It seems like all your concerns/critiques from above would apply equally, but then I don't have any real expertise in the area.

https://youtu.be/EM-gCvhQhPU?t=508

This lady says Betz limit doesn't apply to VAWT.

> Vertical turbines far more efficient when in large-scale wind farms than they are individually

The article is saying that in large-scale wind farms, vertical turbines are more efficient than horizontal axis wind turbines (the "traditional form factor").

With horizontal axis turbines in large wind farms, there is always a loss of efficiency through the "wake effect" where some of the turbines are downwind from the others.

But the study seems to have found that this can actually increase the efficiency of vertical turbines. Which is very unexpected.

I think this is efficiency in terms of much energy you can extract for a given area of sea or land. Wake effects mean that wind turbines cannot be placed in a particular zone downwind of another turbine. If wake effects are lower then you could potentially get a higher density of turbines in a given area. This is something that is already considered in terms of turbine height and placement. Sometimes they are placed at closer intervals along the perimeter of the zone and then lower densities within.

Of course lots of factors are considered with the final "efficiency" being about getting the highest return for an investment.

> "How much energy can we get out of a plot of land of a given size?"

I don't believe this is an answerable question in this format. The size of a plot says nothing of land topography, nor the average wind currents for any given timeframe.

Wind farms are great tech, but adequate calculation of efficiency and cost/benefit is always subjective to individual installations. Solar farm efficiency calculations are easier because the variables at play are much more consistent. Essentially: panel efficiency * sun exposure * array size. I don't believe this formula translates to wind farms.

Finding a more efficient design for wind-to-energy conversion is a lot like making an improvement in the "panel efficiency" part of solar arrays. Or maybe wind has an "array design" variable to consider since one turbine's design can affect the wind energy capacity of another. This isn't the same for solar, unless panels overlap during certain times of the day.

Yes,

This is my favorite infrastructure project concept: https://www.scientificamerican.com/article/offshore-wind-far...

help with hurricanes, direct DC to the entire country, tons of jobs for maintenance, etc

Yes, research has been done, if only because knowing about that is essential for figuring out at what distance from each other you should place your turbines.

See for example https://energyfollower.com/wind-turbine-spacing, https://ep.liu.se/ecp/057/vol15/014/ecp57vol15_014.pdf

There's some research that wind farms at scale have a small but non-negligible warming effect:

https://www.sciencedirect.com/science/article/pii/S254243511...!

Wind encounters far more resistance and obstacles when sweeping over land, ex. cities with buildings (tall and small) and other man made structures and then there are various natural ones - trees, hills, etc.

Windmill probably is much less of a drag (pun!) as compared to above.

On the other other hand they seem mechanically simpler because the entire turbine doesn't have to be mounted to pivot depending on the direction of the wind, and the column that holds up the turbine and blades is much shorter.

Indeed, we have lots of space. The more important efficiency is turning capital into electricity. I believe horizontal turbines still have the edge here. This could possibly change if produced in enough volume to get the manufacturing costs down - it depends if they have an advantage in materials use, install and shipping costs, and maintenance costs.

> vertical turbines boost each other’s performance

Meanwhile, horizontal turbines impair each other's performance when they sit in each other's wake.

I remember reading that the loss of power generation was more than previously expected, as you increase the area of the wind farm?

So, it could be financially worth it to optimise vertical turbines, if they work in a more synergistic way.

Here's a machine-translated post on vertical turbines by one of the pioneers in the modern wind turbine market:

https://translate.google.com/translate?sl=auto&tl=en&u=https...

TLDR; they have been tried out and found impractical.

I'll add to that that many, many years have gone into the manufacturing of current big wind turbines. Making something that can withstand the weather, have a high uptime, relatively cheap to manufacture and put up - these are not easy problems.

I think there may have been turbines with those two problems but that does not mean that all turbines are like that. Merely that there were some issues to sort out back in the day when you read about someone allegedly having these issues.

Basically, noise would indicate either some problem with loose parts, a lot of friction, turbulence or something else that is clearly being inefficient. Obviously to compete with state of the art horizontal turbines, you'd use highly durable materials with awesomely low friction and generally be shooting for very high levels of efficiency.

Some other things I've seen suggests that small vertical turbines are suitable for deployment in urban environments where they work with low/variable wind speeds at completely acceptable noise levels. You could put these on your roof even. I left a link elsewhere in this thread if you are interested.

Basically the article is about a group of scientists that ran the numbers and came up with different conclusions than you. 15% more efficient is quite a lot.

What's the source of the noise? The turbine itself? the air flow around the blades?

All large wind turbines are loud. Like, unbearably loud.