Tag Archives: renewable energy

Vertical solar farms, the next perpetual motion machine

I am a big fan of hydroponics. LED lighting allows growers to deliver a spectrum optimised for plant growth and they can get many times the productivity from a square metre inside under lighting than outside. In the right context, it’s a great idea. Here is a nice image from GE Reports , albeit with pointless scanning.

I don’t think much however of the various ‘futuristic’ artist impressions of external vertical farms with trees likely to fall on pedestrians from 20 floors up. Like this one, described as an ‘environmental alternative’. No it isn’t, its a daft idea that makes a pretty picture, not an alternative.

But as far as silliness is concerned, I suspect I can see one that is coming soon: the vertical solar farm. Here is how it will work, cough. Actually two ways.


A lot of external solar panels on a building will gather solar energy (or solar paint, whatever), and that wonderful renewable energy will then be used to power super-efficient LED lights, illuminating highly efficient solar panels inside. The LED banks and solar panels will be arranged in numerous layers to make lots of nice clean energy. The resultant ‘energy amplifier’ will appear.

A more complex version will use hydroponics instead, converting the externally gather solar energy into plant material to make biofuel to make energy to power the lights during the night.

Some clever-clogs will then work out that the external panels are not needed since the internal panels will make the light to power the LEDs 24/7. People will object, but they’ll just point at the rapidly growing efficiencies of both LEDs and solar panels, especially coupled to other enhancements such as picking the right spectrum for the LEDs. How can it not work?

You know as well as I do, I hope, that this is total nonsense and will remain so. However, you also know as well as I do that some people are very easily taken in. Personally, I can’t wait to see the first claims from some Green company. I wouldn’t be all that surprised if they manage to get a development grant. It would be hilarious if something like this makes it through a patent office somewhere. Perpetual machines don’t go extinct, they just evolve.

Actually, I’m more upset that it isn’t April 1st.

New type of wind harvester

I am moving old blogs across from nvireuk before I close it next month so that I don’t lose them. Here is another. Please don’t take it from this one that I am in favour of wind turbines. I most certainly am not, but if we must use wind power to appease renewable fans, then at least we should do it in ways that are less irritating to humans and wildlife and a little imagination can go a long way with today’s technology compared to the primitive, almost Victorian heavy engineering used for conventional turbines. This method should be a lot quieter, less visually intrusive, about the same efficiency but unlike wind turbines, potentially able to reduce in cost with Moore’s Law. Initial cost would be similar (the costings I mention are based just on their sample prices, which obviously are usually far higher than finished large scale production), so still nowhere near as good as using shale gas, but it could be. Even then, we’d still need backup generation for when the wind isn’t blowing.

Conventional wind energy harvesting uses turbines on a grand scale, connected to a central motor. The whole thing needs heavy engineering, complex control systems and expensive and scarce materials such as neodymium for the motors. It is possible to build a system that is far more elegant, resource-efficient and less intrusive. Perhaps even much cheaper.

Some time ago a Danish company Danfoss, invented plastic capacitors, that generate electrical energy directly when they are bent. Wind pressure could be used to bend small vanes made of this material by pushing it around a spindle. As it rotates, one side goes through extended, the other side is forced to bend on the way back through the gap. By repeated bending and extending every time it rotates, each vane would generate electricity from the wind. These could be arranged in long strings, and many strings made up into a large sail.

The sail would be tethered to an anchor using ropes, and when the wind blows, it would fill up, the vanes would rotate, and energy would be harvested, with no need for a central motor or any heavy engineering. When the wind dies down, the sail would collapse so that it is less visible. Because the vanes individually would be small, just 5-10 centimetres across, no motion would be visible from any distance away, so they would not be as distracting as conventional turbines. Nor would they kill birds. Plastic capacitor sail generators would therefore have a few advantages over conventional approaches.

The disadvantage is that at the moment the material is fairly expensive, but there are excellent prospects for large cost reductions, and these could make it a far cheaper, as well as a greener, way of harvesting wind power.