The California Energy Commission, through its Public Interest Energy Research (PIER) Institute, has made a substantial investment in research in California on energy demand response initiatives. In electricity grids, demand response (DR) changes the traditional way that customers consume electricity in response to supply conditions: for example, electricity customers can reduce their consumption if the price rises during a heat wave. CITRIS has played a key role in developing wireless sensors and their accompanying networking components, both hardware and communications protocols, to enable fine-granularity measurements and monitoring that are facilitating demand response services for consumers and businesses.