XPost: sci.space.policy   
   From: henry@spsystems.net   
      
   In article ,   
   Alex Terrell  wrote:   
   >How many W/m2 can solar panels produce, assuming concentrated or laser   
   >light?   
      
   Nobody has done much work on optimizing solar panels for laser illumination,   
   so I think the answer to that one is "nobody knows".   
      
   Solar-concentrator systems are still somewhat experimental.  (Note that   
   you have to do the concentration near the array -- it is fundamentally   
   impossible to concentrate sunlight into a narrow beam for long-range   
   transmission.)  My impression is that currently feasible concentration   
   factors are relatively small, but I haven't followed this closely.  Do   
   note that the better concentrator arrays generally have to be aimed quite   
   carefully at the light source -- they don't have the wide-angle reception   
   of a normal solar array.   
      
   >...Alternatively, could the laser be converted directly into heat to   
   >drive a closed cycle engine?   
      
   Converting the laser beam into heat is no big deal in priniciple, but then   
   you run into the inefficiency of heat engines, and the need to get rid of   
   a lot of waste heat with a radiator system.  Solar arrays are easier.   
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   MOST launched 30 June; science observations running     |   Henry Spencer   
   since Oct; first surprises seen; papers pending.        | henry@spsystems.net   
      
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