ENERGY TOWERS

Prof. Michael Porch

Technion

The Physical Principle

On 16.8.88 rain drops from a high cloud near Beef Sheva cooled an air column below the cloud in the otherwise dry and warm air. The cold air flowed down toward the ground at a high speed creating two well known natural phenomena: microburst and wind shear.

The generated wind speeds (80 km/h) caused $1 million damage at the local airport. Microbursts occur quite often in nature. In 1994 a Delta Airlines plane crashed in Texas while landing in a microburst, killing all its passengers.

Energy Towers create energy in a similar way:

* Sea Water is pumped to the top of the tower
* The water is sprayed by atomizers
* The droplets cool the dry air
* The cold air rushes down (40-60 kn/h)
* Wind turbines and genrators converty the kinetic energy to electrical energy
* Electricity is delivered at an amazingly low cost.

The Fuel

The fuel of energy towers is hot, dry air and sea water.

QUESTION: where is it available?

ANSWER:

* Solar energy warms moist air at the equatorial regions
* When the air rises up, it cools down and loses its moisture (rain)
* The dry air flows north and south fo the equator and eventually descends at altitudes of 15-30 degrees. It warms up and flows back toward the equator, collecting moisture when passing over oceans.
* These solar circulations which are called "Hadley Cells" produce a steady supply of hot and dry air which creates nost of the large deserts of the world.
* Few percents of this solar energy are sufficient to supply the energy requirments of the entire world.

Features of Energy Towers

The operation of Energy Towers is based on well proven and tested scientific principles. They can be built using off-the-shelf technology.

Their main new dimension is their large scale, which is dictated by the fact that their power increases dramatically with height. The idea of using high energy to produce energy was initally proposed by Carlson

(1980). Carlosn estimated that the required height of such towers would be 2400 m. Knowhow and novel developments at the Technion have made the project economically feasible even at a height lower than 1000 m.

The typical features of Energy Towers

 Height         1000 m          Eiffel Tower - 300 m                                 Sears Tower  - 450 m                                 CNN Tower   -  560 m    Construction                   Suggestion by Starnet                  Lightweight     Aluminum frames                 Space frame     Construction time: 3 years aND $400 million                 surrounded by                 a membrane   Weight                ~ 40,000 tons   only 5x Eiffel Tower No of Elements        ~ IM            CAD is possible                        ~ 20 t/s        Same order as in conventional power                                       plants for cooling                                       Evaporation ~1/2 of water                       ~ 10,000        A novel clog-free narrow spectrum                                       atomizer developed at Technion                                       Other off the shelf sprayers are                                       possible  By products:  Cool air flow from exits  ~ 2 Mm3/s 

Energy towers also provide an infrastructure for very low cost desalination of sea water, using available desalination technology.

QUESTION: Does the world need Energy Towers?

ANSWER: Definitely! It may be applied in about 40 countries.

Inexpensive energy is the key for progress in underdeveloped countries. Energy Towers could provide such energy as well as desalinated water to many of these countires which border on vast deserts.

Additional factors which make Energy Towers very attractive are:

* To avert global climate changes, it is necessary to cut the emissions of carbon dioxide into the atmoshpere. On April 21, 1993 (Earth Day), President Clinton announced that the US will reduce its CO2 emission. It is now clear that his pledge waas not fulfilled and "efforts to reduce CO2 emmisions have failed."

The great experiment: "Life in a high carbon-dioxide atmoshpere seems to be getting underway," writes the Scientific American in June 1994. Energy Towers produce electricity without emitting any carbon dioxide into the atmosphere.

Nuclear energy can also supply electricity without CO2 emissions. Today there is a considerable objection to nuclear energy production. Whatever the future of nuclear energy and knowhow would be, it will not be shared with developing countries that require affordable energy.

* The long term shortage of conventional fuels is confirmed in a new study by Shell International Petroleum Company. The strudy discredits precious conservative World Energy Council predicitions: "Nobody will predict the unfolding reality clearly. But when a major oil company prouects the end of the fossil fuel age, it si a sure harbinger that we move into that period." (Scientific American, June 1994)

Projected timetable and cost

 a - Scientific and technological   12 years        $ 1 million      studies:                      1982-94         Sponsors: Technion and                                                    the Ministry of Energy                                                    & Infrastructure  b - Conceptual design      Detailed pilot design      Legal and patents             12-18 months    $ 3.2 million      G&A + contingencies                           $ 1.8 million  c - Pilot plant construction      Demonstration of technologies 18-24 months    $ 20 million      G&A + contingencies                           $ 6.5 million   d - Final full scale design and     construction of the first     commercial Energy Tower     of 900 m                       3 years         $ 650 million                                                      (nominal)

Israel is looking for business partners to invest in stages b and c for building Energy Towers.