Yes, they're certainly visually appealing, and it makes good sense to try and incorporate infrastructure into bits of stuff that's already around us (see: mobile phone towers that are embedded into signage and stuff so that they're basically invisible)

- They're mostly based on bullshit. Let's have a look:

"The Wind Tree is being developed by NewWind and has 72 artificial leaves. Each one is a vertical axis turbine, vaguely conical in shape. Because each one has little mass, they can generate power with a gentle breeze as slow as 2 meters per second (4.4 mph). This could make the Wind Tree useful for generating power, on average, 280 days of the year. Total power output across all 72 turbines is estimated at 3.1 kW. Larger traditional turbines can produce considerably more power, but they need more wind to get going and thus operate fewer days of the year."

From: http://www.geek.com/.../new-wind-turbine-looks-like-a.../

Okay, so, first of all, they intentionally avoid talking about how much power a traditional large-scale 'horizontal axis wind turbine' (or, HAWT) generates. Our standard models are 3 megawatts, or 3,000 kilowatts.

If 72 turbines produce 3.1 kilowatts, each turbine produces 0.04 kilowatts (or, 43 watts, which is about enough to power a small laptop or a pedestal fan).

So, for each standard 3MW HAWT, you'd need 3/0.0000431 = 69,677 'leaves'.

For each 'tree', each generating (we assume) 3.1 kW, you'd need 3/0.031 = 967 separate 'trees'. So, is the visual impact of nearly 1,000 plasticised artificial trees, each needing maintenance, the same as one large turbine? (To replace a 67-turbine 200 megawatt wind farm, you'd need 193,400 'trees')

Anyway, it gets worse. They say it's better because the start up speed is 2 m/s, much lower than a HAWT. But a HAWT starts generating at 4m/s - not a huge difference, considering HAWTs can capture up to 25 m/s (and they don't say what the max output of the tree-leaf-thing is).

But wait! There's more! Wind turbines actually do operatefor more than 280 days out of a year. At least, the ones we build in Australia do. They run for at least 90% of total time (~320 days). So, basically, they plucked that bullshit straight of thin air. Also: sure, HAWTs need higher wind speeds to run, but they can handle HUGE wind speeds - can these things handle huge wind speeds? If not, then the advantage of starting earlier is lost because they 'finish' quicker down the wind speed scale.

Also:

- Yes, HAWTs are big, but part of the reason they exist is to create deep, rapid cuts in our reliance on fossil fuel energy. We can't do that without generating massive amounts of energy, and for that, you need big, tall structures. This leafy shit won't cut it when it comes to replace megawatt-hours of coal.

- Yes, HAWTs make noise, but honestly, that impact is negligible, particularly compared to the impacts of existing technology, and also easily mitigated with good community ownership schemes.

Basically, this is just another case of credulous journalists. It really pisses me off. They're raking in cash (the journalists and the people making the machines) from the genuine and honest excitement that people feel when it comes to technological solutions to climate change.

I'm not saying these things shouldn't be invested in and researched. But, god damn, be mathematically honest, and don't base your business model on shitting all over technology that's already up and running, and already pushing coal fired power stations