Bullitt Centre - Connecting technologies and 90 percent rule

 
Another example of connecting technologies - Bullitt Centre in Seattle - has been called the world’s greenest office building.

The 52,000-square-foot building outfitted with cutting-edge environmental technologies, such as insulation and energy-saving heating and cooling systems, aims at meeting the rigorous standards of the Living Building Challenge. It is supposed to be completely powered by the 575 photovoltaic solar panels on the over sized roof. Completed in 2013 (a year behind the schedule), the US$18.5 million, 6-storey building, designed by Miller Hull Partnerships, is built to be “zero-energy”.

To make enough room for 14,000 square feet array of solar panels the roof had to be made projected as much as 20 feet beyond the building's perimeter. According to the designers, the solar array delivers 242 kilowatts of power in total. In the summer, it will produce more electricity than it uses, and in the winter it will produce less. The surplus power will be sold into the Seattle electric grid. The building then draws electricity from the grid in the winter months when production is low. To achieve its “net zero energy” goal, the summer production surplus must meet or exceed the winter production deficit. While strictly speaking it is not a 100% efficiency, this is a way around the 90 percent barrier.