Recently  we started this feature of interviews with leading scientists and thinkers on the subject of energy. The first interview was with Dennis M. Bushnell, Chief Scientist, NASA, Langley Research Center.   This is the second of what will be an ongoing series of interviews in the weeks ahead.  Regular readers of this blog know that I believe that facing and solving the multiple issues concerning energy is the single most pressing problem that we face as a species.  There is a lot of media coverage about energy, alternative energy and global warming, but what has been missing is the knowledge and point of view of scientists, at least in the main stream media.  What do the best and brightest think about energy and the future?  Please continue to come to and find out.


 This week we interview Darel Preble.  Darel is chair of the Space Solar Power Workshop, a volunteer organization dedicated to finding and understanding the cleanest, most reliable, baseload energy source - that is SSP. It operates under the Space Solar Power Institute, 501(c)3 educational corporation, which Darel chartered in 1997.  In 1994, 1995, and 1996 he wrote a series of three annual white papers (on his own time and dime) for the aerospace and  electric power industries.  Darel was then a strategic and advanced systems energy analyst and the Nuclear Security Analyst at The Southern Company. He left Southern in 1997 when it was the largest electric utility in the US. [Note: I asked Darel to include links that he felt might be of interest to those that really want to dig a bit deeper on the urgent energy issues of today]


Wireless Power Transmission

1.   Scientificblogging: In your presentation at the Foundation for the Future’s “Energy Challenges:  The Next Thousand Years” you were quite emphatic about the urgency for humanity to change energy consumption, and the types of energy that is used.  Please elaborate and perhaps suggest timelines for this to occur.


Preble:  Oil, gas and coal - all fossil fuels are expected to reach peak production and begin to decline between 2008 and 2025. The result of our burning these fossil fuels has been climate change. Climate change is in many ways a more dangerous problem, but very slow moving and poorly understood. Few people understand the massive scope or problems encompassed, because they are so slow moving and complex -  and many effects are positive - cotton will benefit, for example, if we have the water to grow it.  In brief, "climate change" requires us to fully understand and manage our world as never before.  So far we are failing this test miserably and the ultimate cost will be very high.  It took years to assemble two chapters summarizing thousands of studies into climate change effects. Those are also on the SSPW website. As Robert Hirsch has stated in his Hirsch report to the Dept of Energy, we are doing nothing on the MASSIVE energy scale required to cleanly repower our planet.

Canada, for example, is realizing that yesterday's energy players and promises are going nowhere fast, as Canada's CO2 has increased 30% since they signed Kyoto.  Promises are cheap.  Wrestling with the magnitude of our energy/environment problems leaves few clean, baseload, and real energy options, the single exception is SSP.

  "If we continue doing what we are doing now, we are in deep trouble," said Ogunlade Davidson, co-chairman of IPCC Working Group III that produced the report.  The document says the world has the technology and wealth now to act decisively in time to avoid a sharp rise in temperatures that scientists say would wipe out species, raise ocean levels, trigger droughts in some places and flooding in others, and wreak economic havoc.  -  “Changes in lifestyle can slow warming, scientists say”, Keay Davidson, SF Chronicle Science Writer May 5, 2007

The "warnings could not be more alarming," said Rep. Edward Markey, D-Mass., chairman of the House Select Committee on Energy Independence and Global Warming, "but this report also gives much reason for hope. We know what we need to do to protect the planet. The only question is whether we have the wisdom to do so in time to make a difference."  - “Climate Plan Arms World for Key Talks”, Associated Press,  By Michael Casey, May 4, 2007


 2.   During your presentation you spoke about the decline in nutritional value of the world’s agricultural products, could you please explain that dynamic.

Preble:  Sure.  Let's examine wheat and rice - the worlds top two grains. At doubled carbon dioxide levels, plant-available nitrogen decreases 40 to 50 %, resulting in reduced nutrition from forage and grasses grown under doubled CO2. Wheat grown at doubled CO2 declines in protein content by 9-13% and produces poorer dough of lower extensibility and decreased loaf volume.  Hence flour, produced from wheat grain developed at high temperatures and in elevated CO2, degrades. “The nutritive value of rice was also changed at high CO2 due to a reduction in grain nitrogen and, therefore, protein concentration.”  The protein content of rice declines under combined increases of temperature and CO2. Iron and zinc concentrations in rice, important for human nutrition, would be lower. (By not eating whole grain products and eating "junk food" we have voluntarily reduced our nutritional intake by even more, so this is cumulative. We are becoming increasingly overfed, but undernourished.)  Ruminants, including cattle, sheep, oxen, buffalo, deer, - the source of nearly all the milk and half the meat the world eats - will  gain weight much more slowly grazing on forage growing under doubled CO2. CO2 is expected to reach doubled levels by mid century, under business as usual assumptions.

 3.   Do you believe in Peak Oil, and if so, when do you see the earth running out of its supply of petroleum?

Preble: The most current and authoritative research predicts global oil production to peak during the 2008 to 2018 timeframe. We will never "run out" of petroleum; it will simply become too expensive to burn in our cars and trucks. "In a worst-case scenario, global oil production may reach its peak in 2008, before starting to decline. In a best-case scenario, this peak would not be reached until 2018. These estimates are made by Fredrik Robelius, whose doctoral dissertation estimates future oil production". -  and
The most current and authoritative research predicts global coal production to peak around 2025. - "Peak coal by 2025 say researchers", by Dr. Werner Zittel and Jörg Schindler
Biofuels are not the answer (from EnergyPulse Weekly): Peak Soil: Why Cellulosic ethanol and other Biofuels are Not Sustainable and a Threat to America's National Security - Part I
Alice Friedemann, Freelance Journalist  - two more parts also linkable from there.

 4.   At the conference, you were one of the strongest proponents of Space Solar Energy.  Please give an over view of what that is?

Preble:  The single most important action this country can take to address energy security and climate change is to pass the Sunsat Act legislation to start building a space solar power system (SSPS). These large satellites - kilometers across - capture the suns energy in high orbit and cleanly beam it down using wireless power transfer (WPT) to rectennas on the ground - directly into the electric power grids of contracting utilities. (87% efficient WPT was first demonstrated by Bill Brown of Raytheon in 1975.) Rectennas would also be kilometers across, but crops or other farming could be done under these, just as now is done under electric power lines.  The Space Solar Power Workshop website at  has been updated with a few more presentations. Give us an email if you would like to help.


5.   Why do you think  SSP  is the best long term energy solution for the planet?

Preble: We have analyzed the competing power production methods and, briefly summarized below, find no other baseload energy source as clean, safe or reliable considering the MASSIVE energy quantities we require.

Fossil Fuel No Yes Decades remaining Yes
Nuclear No Yes Fuel very limited Yes
Wind Power Yes Yes No, intermittent No
Ground Solar Yes Yes No, intermittent No
Hydro Yes Yes No; drought; complex scheduling
Bio-fuels Yes <;/td>Yes Very limited quantities - competes directly with food production. 
SSP Yes Yes Yes Yes

6.   Do we have the current technological capability to actually do this, and if so, what is the cost and timeline?

Preble:   Yes.  This is  what  the SSPW website was created to explain.  To collect the necessary technical details from many fields and show that SSP can be built now.  There is MUCH work to be done, but it is work we understand how to do because we have done all these things before. For example, the first major key is reducing the cost of space transportation. This must be done to enable SSP to build these satellites to deliver power at competitive prices - about 4 cents per Kwh wholesale to the utility. Even the cheapest space transportation of today, (about $1500/lb to LEO) from SpaceX or Dnepr, is about ten times too expensive to  reach profitability - to continue operating.  BUT if there were a market for hundreds of times more launches, which  is exactly what Sunsat Corp. would provide, those costs would drop by more than that factor of ten. But there must be a  financially STRONG company -Sunsat Corp. - to write the big checks to buy that space transportation.  The same story is true of space photovoltaics and rectenna construction etc., 

Sunsat Corp legislation has been drafted and a copy is on the SSPW website:  modeled after Comsat Act legislation.   Comsat Corp. was chartered by Congress in 1962 to build communications satellites in space. It successfully created what is now a $100 Billion per year industry. Sunsat Corp should be chartered by Congress now to build power satellites in space. If this act were passed by Congress in 2007, it would take five years to gear up to begin producing Space Solar Power satellites (SSPs). It is an Apollo style project. In ten years we could be building SSPs fast enough to stop CO2  from increasing. Huge economic benefits would be attached, which we are even now seeking to accurately document. There is no other comparable, or more promising, energy source than directly tapping into our sun's power. SSP is the cleanest, safest and most reliable baseload power known with virtually unlimited potential. 


7.   How does Space Solar Energy compare with the terrestrial solar energy that is known to this readership?


Preble: Good question.   Solar energy captured on the ground, or terrestrial solar, provides power about 25-30% of  a typical day. The big problem is  we don't  know how to store  MASSIVE quantities of power cheaply.  Fortunately, solar captured in high orbit, Geosynchronous orbit (GSO), is available 99% of the year - even at night - summer or winter.  Even the best power plants on earth, coal or nuclear baseload plants, are only available about 90% of the year.  A solar panel in GSO produces about 9.6 times as much energy per day as that same panel sitting at a typical U.S. location, such as a roof.  The trick is getting the panel up to GSO


8.   In addition to the web site, are there any other resources you think might be of interest to my readers?


Preble:   Many.  Every  component SSP technology or competing power technology has  good sites on the web known to  researchers that  tracks developments. I suggest looking at the presentations and chapters and checking the many hundreds of background references.  Read the space transportation chapter and see it's background websites, like Clark Lindsay' RLV newsite -


9.   What needs to happen to make this a reality?  How essential is it for the U.S. government and other governments to coordinate and support this effort?


Preble: Congress must charter Sunsat Corp. That is the  keystone legislation to enable and build the public/private company to get the job done, just as Comsat did.  Other "nice things" to do - build a Wireless Power Transmission demonstration site, but really this should be done by a lab connected to Sunsat Corp, just as Comsat had a space communications lab.

On a much smaller scale, we are now working to raise money to do an  SSP Economic Impact study, etc., led by Dr. Tom Matula, and many others and present that at an SSP Workshop annually. There is zero funding for SSP in the U.S.


10.   In a fully realized state, how much of humanity’s energy needs can be met by Space Solar Energy?


Preble:  Probably around 90% by 2100 if we work at it.

 11.   Given that fully functional Space Solar Platforms will take some time to become fully operational what recommendations do you have for alternative energy and conservation solutions in the short term?   

Preble: Conservation is the "cheapest" energy source today -  Carpooling, more energy efficient lighting; refrigerators; air conditioners, cars, etc.,

 12.   Any final thoughts or comments? 

Preble:   Sure.  Don't be daunted by the massive quantity of information. Inform yourself by studying the pieces just as you are doing now.  Remember the old joke, "How do you eat an elephant?  One bite at a time." 


 Scientificblogging:  Thank you so much for your time, your thoughts and all the resource links you provided for my readers.