Starting next month, California’s state capital campus, a complex of 23 buildings encompassing 5.5 million sq ft, will be cooled by water chilled in a 4.25-million-gal thermal-energy storage tank. The 140-ft-tall metal cone is the final phase of a $181-million central-plant replacement on course to receive the second-highest ranking—LEED Gold—of the U.S. Green Building Council’s Leadership in Energy and Environmental Design green-building rating system. Photo: Todd Quam Digital Sky Aerial Imaging Payback period is three to four years for the energy-efficient systems in the state capital’s $181-million district heating and cooling plant. The 78,000-sq-ft California central plant is the largest
Arch dams, classically curved monoliths situated in narrow valleys, are not as common as other types of dams, such as embankment dams and gravity dams. ENR takes a look at some of the biggest arch dams in the world, both completed and under construction.