Sacramento Municipal Utility District is leading the national shift to �smart grid� networks with help from a $127-million stimulus grant. Photo: SMUD In June, SMUD hired Greenville, South Carolina-based Utility Partners of America, Inc. for $7.5 million to replace the smattering of 620,000 electromechanical and first-generation solid-state meters with Landis+Gyr smart meters that collect usage information digitally in real time from 50,000 demand-response, control relay access points. The digital meters will allow customers who generate their own energy using solar or wind turbines to act as micro-generators and sell power to the grid. The devices could also improve customer service
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.