Suntek is built upon four surprising ideas, each based on the previous:

Imagine an insulating material that is also transparent — it sounds like a contradiction in terms.  Such a material prevents the flow of heat, yet is invisible. Called LOW-E, it makes glazings that insulate like walls, yet transmit 50% of sunlight. A solar collector this efficient has the unique ability to heat buildings in freezing weather with only cloudlight, as shown in field tests by the European Union. 

Costing only $0.03 per square foot more, enough Low-E windows have been sold to cover the state of Rhode Island, and they are saving 3.7% of world energy, twice as much as all wind and solar energy.

"Low-E is one of the 100 most important inventions in the last 100 years." — Popular Science.

The blue numbers in this Overview sound too good to be true, but they are easy to verify — just click them for the solid, detailed references and simple arithmetic behind them.  For example, this, briefly, is the arithmetic behind the first blue number:

According to the International Energy Agency, 20% of world energy is used to heat buildings.  Before Low-E, 20% of that heat went out the windows, or: 20% x 20% = 4% of world energy.  Thus, by tripling the insulating value of windows, Low-E can save: 4% x 3/4 = 3% of world energy at market saturation.  But a Low-E window is warmer than a non-Low-E window, which increases the temperature that you feel, which allows the thermostat to be turned down.  This subtle effect doubles Low-E’s potential energy savings to 6%.

In the industrial world, where 2/3 of world energy is consumed, 2/3 of windows have Low-E, so that:   6% x 2/3 x 2/3 = 2.7% of world energy is being saved by Low-E.  However, Low-E is also used in the non-industrialized world, and it also saves air conditioning energy as well as heating energy, which brings the total world energy being saved by Low-E up to 3.7%.

Imagine a plastic film that, after your hand has rested on it for five seconds, leaves a white handprint that quickly disappears as the film cools to room temperature.  CLOUD GEL is a unique glazing material that transmits 90% of sunlight when heat or illumination are needed, but by turning opaque white, reflects 85% of sunlight when a room is too warm or bright.  So in the summer, when a solar collector or greenhouse is too warm, the Cloud Gel automatically turns white, working like a thermostat.  It is made both as a flexible film and with glass, like Low-E.  Its proprietary markets are $27 billion.

When the sun shines on a Cloud Gel equipped skylight, it turns white, transmitting only a small portion.  But when the sun goes behind a cloud, the Cloud Gel turns transparent, so the illumination level stays constant.  Cloud Gel makes skylight illumination much less expensive than electric lighting, which, besides using electricity, incurs 5 to 10 time the air conditioning costs of a Cloud Gel skylight.

Imagine a roofing panel that transforms any weather into good weather.  WEATHER PANELS are made with Low-E and Cloud Gel, and have a thin layer of water for overnight heat storage. Weather Panels for solar heating are opaque, with an ordinary ceiling finish. But for illumination and greenhouses, the Panels are transparent. 

Most heating energy is consumed in cloudy winter climates.  Because Weather Panels heat with cloudlight, which comes from all parts of the sky, solar heated buildings can now be any shape, making solar heating marketable at last.  A building with a Weather Panel roof was tested by the European Union.  It was 85% solar heated in cold and cloudy Brussels, where 50% had been tops.  Since Weather Panels cost the same as the roof and heater they replace, their heat and illumination are free.  This unique performance comes from molecules and electrons that have been carefully choreographed to capture and regulate sunlight.

The Weather Panel can supply one-sixth of the world’s energy, free; save 1.5 million lives each year from coal and oil pollution; and greatly reduce global warming. With $175 billion (€125 billion) markets, the Weather Panel is a proprietary profit center that can drive rapid global market saturation, just as Low-E did. This simple technology is much easier to implement than all other energy technologies — which are neither simple nor free.


According to the International Energy Institute, 20% of world energy is used to heat buildings.  European Union field tests show that Cloud Gel roofs produce 85% of the heat for two story buildings in Tokyo, Boston, and Paris—which have typical heating climates.  85% of building construction is of the top two stories of buildings.  Thus:  20% x 85% x 85% = 14.5%  of world energy can be produced by solar heating with Cloud Gel.

7% of world energy is used for illumination in buildings.  40% of building construction is of the top story, which can be illuminated with Cloud Gel skylights—because they do not cause prohibitive air conditioning costs in the summer.  65% of lighting is used during daylight hours.  Thus:  7% x 40% x 65% = 1.8%  of world energy can be produced by Cloud Gel skylights.

14.5% + 1.8% = 16.3%, or one-sixth of world energy can be produced by the Weather Panel—not including the energy from Weather Panels used for illumination.

Imagine acres of transparent roof that, when the sun comes out from behind a cloud, instantly turns white.  It's a building shell made from Weather Panels that is called the CLIMATE ENVELOPE because it creates a year-round tropical climate with no supplemental heating in Paris, Boston, or Tokyo.  As well as heat and illumination, the Envelope gives protection from wind, rain, snow, and glare for gardens, trees, and people.  It will cost little more than a sheet metal warehouse.  By covering acres with cheap good weather, the Climate Envelope will radically change both the function and the form of architecture.


Weather Panel architecture can be exactly the same as any other architecture, except the roof is made from Weather Panels, and has a 45° slope for snow to slide off.  First the building is designed, and then a Weather Panel roof is selected for heating and illumination—With the same installed cost as a conventional roof and heating system, and zero energy costs.  The architecture is not solar, just the free heat and illumination.

The uninspired design below is a solar and thermal model from which more complex and useful solar architecture may be elaborated.  This building could be four 1500 sq ft (140 sq meter) apartments.  Designed for cold, cloudy winters, the entire roof is made from Weather Panels and their steel structural frame.  Heating Weather Panels have a prefabricated interior finish, such as plaster, wallpaper, or wood veneer.  Their exterior may be any dark color.  Illumination Weather Panels are shown below as blue.

In winter, the top story is heated uniformly by thermal radiation from the Weather Panels’ heat storage, which covers the entire ceiling.  Hot air taken from the top ridge of the ceiling is circulated with fans and ducts to heat the lower stories.  During sunny summer weather, the fans circulate outside air through the top story to remove heat from the 4% sunlight absorption of the Weather Panels when they are white.  On cool summer nights the fans and ducts circulate outside air through the whole building, cooling everything, especially the thermal storage in the top story ceiling. This stored “cool” cools the building during the day.


The Climate Envelope is a large transparent shell enclosing a constant climate of, for example, tropical gardens with ripe mangos and bananas in the dead of winter in Tokyo, Boston, or Paris—and with 100% solar heating.  The entire shell will switch from clear to white the minute the sun appears from behind a cloud.  This dramatic display of a technology that can provide one sixth of the world’s energy free will generate much media coverage. 

Through its molecularly designed skin of transparent Weather Panels, the Climate Envelope combines a building’s shelter functions with its energy functions.  Removing the weather protection and structural restraints from the buildings inside the Envelope produces a relaxation of its internal architecture.  Activities that now occur inside for climate reasons will take place in the open air.

When mass produced, the Climate Envelope will cost approximately $35/sqare foot (€300/sqare meter) of covered area; not much more than a heated steel warehouse.  It can be designed, shipped and erected in three weeks, and will provide 40 years of shelter, free heat, and illumination.  First use will probably be for covering community or shopping centers, housing developments, tropical parks, etc.  A Climate Envelope was considered for the all-glass water sports stadium at the Beijing Olympics.


Suntek's next product, the Weather Panel, is prefabricated roof sections made with Low-E to collect solar heat or light, and with Cloud Gel to keep room temperature and illumination level constant.  There is also a thin layer of water for overnight heat storage.  For heating, Weather Panels have a ceiling finish, such as plaster, wallpaper, or wood veneer.  For illumination and greenhouses, they are transparent.  To build a roof, these panels are simply bolted into a steel frame.

Low-E insulates so well that it collects heat from cloud-covered skies—even in freezing weather!  Because Weather Panels heat with cloudlight, which comes from all parts of the sky, solar heated buildings can now be any shape.  A Weather Panel roof has zero impact on building design, making solar heating marketable at last.

With automated Panel production, cost is the same as a traditional roof plus heating system—so the heat and illumination are free.  Prefabricated Weather Panels remove the three market barriers hobbling solar heating: awkwardly shaped buildings, low efficiency in cloudy winters, and no profitable, easy-to-use product.  Proprietary world markets are $175 billion (€125 billion).

Weather Panel roofs produce 85% of a building’s heating energy — even in the cold, cloudy climates where most heating energy is consumed, and where 50% had been tops.  This simple technology is much easier to implement than all other energy technologies—which are neither simple nor free.  It can produce one-sixth of world energy and save 1.5 million lives per year from pollution.

The graph below shows the European Union’s test results for a building like the previous illustration of a four-apartment building with a Weather Panel roof.  They extrapolated this winter performance to an annual solar heating of 85%. This performance was achieved with cloudlight alone; the sun never came out during the test period.

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Surprisingly, for skylights and transparent building shells such as a Climate Envelope or greenhouse, the best way to keep them cool in the summer is with the same Weather Panel roofs that are the only solar heating that really works in cloudy winters.  While sunlight intensity varies, the Cloud Gel responds by reducing light transmission to the constant low levels required by people, vegetables, fruits, and flowers.  Its light transmission and temperature of clouding are tuned to each crop.  This shading also reduces the enormous cooling costs in hot, sunny weather. For summer cooling , Low-E reduces heat transmission into the building, rather than, as when solar heating, it reduces heat transmission out of  the building.


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Suntek was founded at MIT to research, develop, and commercialize molecularly designed energy materials for the building industry.  Suntek’s Founder, Day Chahroudi, was a physicist at Livermore National Laboratory, taught architecture at MIT, and is also a chemist and an engineer.  He has 40 years of experience inventing, developing, building factories for, and entrepreneuring products that provide renewable energy for buildings.

Suntek’s first product, Low-E (U.S. patent 3,953,110), is a ubiquitous but invisible coating on windows that insulates them to reduce heating and cooling costs.  It pays for itself in a week, providing free energy for 40 years.  “Without a doubt, Low-E was the biggest development in the glass industry during the last decade.  Sales of Low-E products have grown 13% each year since 1990.” — Lead sentence from the 1998 Glass Digest Annual Forecast Issue, ‘Innovations Propel the Industry’.

Low-E, has reduced world energy consumption by 3.7%, tripled window sales to $100 billion saved 14 million lives by reducing oil and coal pollution — but was developed and brought to market with only $6 million.  Low-E has reduced world energy consumption by twice as much as all wind and solar energy, but with less than 0.1% their R&D costs.  With only $10 million, Suntek is ready to market a second product that can provide one-sixth of world energy, clean and free. 

Low-E’s high profitability to its users, manufacturers, and investors was the driver behind its rapid global market saturation.  For every dollar invested in Suntek’s development and entrepreneuring of Low-E, the glass multinationals invested hundreds of dollars in building factories and marketing.  Each dollar invested in Suntek has saved two lives and the energy that 40 people are using. Synergizing healing the planet with profits by harnessing multinationals to manufacture and market highly profitable products with major environmental benefits is a strategy Suntek pioneered 30 years ago.

90% of windows sold have the invisible Low-E coating, but few people know about it—or its enormous environmental and financial impact.  Truly, Suntek is the elephant in clean energy’s room.  Outside the clean energy box, fundamental innovation in exactly the right place creates enormous markets—with unusual profitability driving rapid global saturation.

$10 million has been invested in Suntek’s development of Cloud Gel. Saint-Gobain, the world’s largest producer of building materials, with sales of $15 billion, has invested $1.5 million in Cloud Gel development and evaluation.  Suntek’s strategic partner, Asahi, the world’s largest glass manufacturer, with sales of $10 billion, is evaluating Cloud Gel for marketing in Europe and Japan.  Cloud Gel has proprietary markets of $27 billion (€18 billion), and will save 1.5 million lives per year at market saturation.

Suntek has a production capacity of 10 million square feet (1 million square meters) per year of the Cloud Gel Polymer, and of the Cloud Gel Polymer laminated between plastic films.  A factory that laminates the Polymer between glass has been patented.


Market Segment
World Production, million sq ft/yr
Part of Market that Benefits from Cloud Gel
Market Size, million/yr at
$3.50/sq ft or €30/sq M
Payback, months
Skylight            120
$       300
€       200
Sunroom            210
$       600
€       400
Non-view Window         6,600
$    2,300
€    1,600
Commercial Greenhouse            160
$       400
€       300
$    3,600
€    2,600
Solar Heat         9,200
$  21,000
€  15,000
Solar Illumination    
$    2,800
€    2,000
$  27,400
€  19,600


"I am convinced that we will have a great collaboration.”

— Marc Van Den Neste, Vice President, Innovation and R&D, Asahi Group, world’s largest glass manufacturer, with $10 billion sales.

“Suntek has demonstrated the ability to develop innovative value-added products for the architectural glass industry.  Encouraged by Suntek’s broad technological base — from the development of Low-E with its high market acceptance, to the promising field test results for the solar heating roof panels, to the large market segments addressed in Europe by Cloud Gel — Saint-Roch was pleased to sign a $15 million Evaluation Agreement with Suntek.
It is our belief that the Cloud Gel technology is the best performing and least expensive optical shutter available; therefore, in order to be first in the marketplace, it is essential that the process of Cloud Gel’s development and commercialization be accelerated.”

— Raymond Buekenhout, President of Saint-Roch, then the technology leading subsidiary of Saint Gobain, world’s second largest glass manufacturer and largest building materials manufacterer, with $15 billion sales.

“We see the potential for Cloud Gel and would like to move forward.  Pilkington should consider Cloud Gel for all the major markets that we serve.”

Mike Wood, Market Manager, Advanced Products, Pilkington, the world’s third largest glass manufacturer.

“Bringing Cloud Gel to market gives a significant tool for keeping the earth replenished — simply and inexpensively.”

Amory Lovins, Director, Rocky Mountain Institute.

“The Weather Panel is a product for which we have been waiting... we expect a very high application potential for the European market.”

— Dr. A. Goetzberger, President, International Solar Energy Society.

Time Magazine, in a cover article on global warming, under “What You Can Do”: the most effective action — three times better than trading in an SUV for a compact — is to  “Install energy efficient [Low-E] windows.”