wblog

The amount of energy which is present in the high altitude wind is several times bigger than the one that is possible to harvest on the ground or close to the ground level. For more detailed information just read on the KiteGen® website.

Harvesting the power of the high altitude wind is not an easy task. A lot of different technologies need to be combined to actually build a machine able to convert the high wind altitude wind in electric energy. An interesting exchange messages was the one between Bill Gates, Ken Caldeira and Massimo Ippolito.

Everything started after Bill Gates read the Sustainable Energy without the hot air written by David McKay, without finding any mention of the high altitude wind as an option to produce energy.

He asked the opinion of Ken Caldeira on that regard. We report Caldeira’s answer for the reader’s convenience.

I have spoken with several people in several companies and they all seem to think different things are the main impediment.

My understanding is that one of the big impediments is tether mass, and there are big tradeoffs with mass of the conductor and insulation versus how high up you can go. It might be that we would require something nearly magical to make such systems really work economically.

(Everything else you mention is also a concern.)

I would say that this is one area in which the size of the investment compared to the size of potential return is tiny, especially when compared with investments such as fusion power.

We recently did a study on steadiness and availability of high altitude winds. The conclusion is that there is a huge amount of power available but that it still is too unsteady to provide base load power without continental (or global?) scale distribution systems, back-up power, or unbelievable amounts of storage.

The other thing we should recall is that if we were to meet future power demand by this source exclusively, we must intercept more than 1% of natural flows. I think when we get above a 1% change in a natural system, we need to be concerned about large scale unintended consequences. Remember, global warming is basically a 1% problem – 1% warming of our 288 K planetary temperature. (That is one reason why solar is so attractive – with solar we are talking about capturing 0.01 % of the energy that hits the ground.)

The notes were quoted by the seeker blog however, in the original thread there is also the reply of Massimo Ippolito, the KiteGen® founder, which we report here as well

Thanks to Ken Caldeira to focus the conducting tether limit.
The italian KiteGen concept early addressed the power cable issue, the electricity generation is done at the ground level, the tether in KiteGen are only force and movement transmitters.
An half inch tether diameter is capable to transfer some 6MW of mechanical power without fatigue.
The KiteGen Carousel is the first concept able to deliver several GW of power with a projected investment of a fraction of a nuclear power plant.
David MacKay didn’t include high wind because he had some understanding delay on the concept, he declared that he wrote only about well understood concepts.
I am surprised about the difficult to well understand the technology potential, I am always available to explain in detail our technology.
The 1% effect on the atmosphere, if the method will be deployed to cover the full mankind primary energy requirement,
could be easily controlled and modulated with an international coordination, in order to make the climatic impact neutral or beneficial.
Regards,
Massimo Ippolito
Kite Gen Research founder

The thread is dated January 2010 and the work progressed. About the latest point on the effect on the climate, Caldeira shown a simulation where deploying a high altitude wind technology at a density of 1 m²/Km³ will affect the world temperature for only 0.04 °C, having no effect on global climate but being able to harvest 18 TW, more of the total energy consumption used by the mainkind nowadays.