When somebody mentions renewable energy, most of us think primarily of methods we can use for home production, namely wind turbines and solar panels. However, there are a number of alternative energy sources still waiting to break through into the public conscience. Airborne forms of wind power are arguably some of the most exciting amongst them;
What Are They?
Whilst wind power is hardly novel, the current method of harnessing it via turbines raises a few problems. For one, their opponents think them unsightly. Secondly, by being placed at relatively low altitude, they miss many of the higher wind speeds.
Solutions to this are being worked on. Kite power gets around the altitude problem, but, as they are tethered to stations on the ground, they’re are arguably still an eye sore, whilst ‘flying wings’ which work in a similar way, but have propellers, are even less obtrusive, with only a cord connecting them to the ground to send power to the grid. Although early prototypes are singular, we could soon be seeing a new generation of wind farms flying in the air; rather than the turbines which take up ground space. ‘Kitegen and Makani are the most widely known and theorized systems.
How Does It Work?
Both systems utilise either a kite or wing, which flies freely in the sky and is connected to a power station on the ground via a flexible link. The kite itself has been designed as to operate in an up and down motion as much as possible, as the power is generated better in vertical rising and falling than in pivoting on its axis.
Their flight paths are pre-calculated to take advantage of the wind currents, and the power is generated by the kite pulling on a ground based turbine. The movement of this turbine on the surface is what generates the electricity or power. A radar system has been designed and implemented so that the kites can be manoeuvred to avoid collisions with airborne objects such as planes, helicopters or birds, whilst the wings are computer piloted to adjust their course to make the most of the available wind.
With the recent advent of flexible and lightweight alternatives to the photovoltaic glass/silicon solar panels, there’s no reason why the kites can’t have solar cells implemented onto their surface. In future major players to may well come together and take a risk on this venture.
What Does It Mean for The Future of Renewable Energy?
Anybody who has ever stood on the roof of a tall building knows that wind power increases with height. Conventional wind turbines are limited to around 100m because of their size and weight, and so their power output potential is already capped. Barring a breakthrough in lighter, stronger and cheaper materials; this isn’t likely to change any time soon.
The ace in the sleeve of airborne generation is really the spatial output. Farms of wind turbines can snake across hills for up to 20 miles, they have to be spaced in a particular manner as to not affect the air currents and decrease the efficiency of the turbines near to them. Kites could find the same power output that a county’s worth of turbines could find, over the area of a town or city. And that raises another point, there’s no reason why you can’t fly these kite systems over cities as long as they’re high enough to avoid the turbulence caused by buildings. Wind turbines are currently restricted to wide open areas and eco scientists are constantly looking to building turbines out to sea, an expensive venture.
Wind isn’t always blowing, that’s a fact; but if we can ensure that the back-up systems are running from renewable resources too; then there’s absolutely no excuse for us to not put a halt to the destructive burning of fossil fuels.
Will Gold is one of the one of the team over at Casa Energy. He specializes on renewables and aims to inform readers of developments in the world of green energy. You can get in touch with him via Facebook or Twitter.
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