So a system using both might cost less than $1 million.
The system will cost about $120 million to put in place.
The system, described as the largest ever built, cost $400,000.
The agency said the new system could not be ready before 2009 and would cost too much.
A 10-kilowatt system, enough to power a large house, costs about $7,700.
Similar systems cost twice that much just a year ago.
"For larger families, the system would cost $185 a month."
The system cost $250 million and has been working since May 2009.
The present system simply costs the general public too much.
The system costs $5,000 but does not include a camera.
