According to Treehugger.com, a company called Kingtec Technologies claims to have made that goal a reality. Their K25Z-4 unit, based on DC-powered truck air conditioners, claims to achieve “off grid” performance, and retails for just under $3000.
The unit’s output is relatively modest. It produces about 16,000 Btu of cooling power—enough for about a 600 sq. ft. area. That might not cut it in a conventional home—but net zero designs might be able to make it work.
Another company (www.nudymasolar.com) has developed a similar unit with an output of 10,000 Btu. They sell the basic unit with panels for about $4,600.00