Houston Mayor Annise Parker said her city has signed an agreement with locally based Reliant Energy, an NRG Energy Inc. company, to purchase more than 140 MW of renewable power through June 30, 2015. Parker said the city’s purchase of green power will account for half of its annual electricity demand, making it the largest municipal purchaser of renewable power in the nation, and in the top 10 overall nationally, according to federal energy statistical estimates. Through Reliant, Houston has purchased renewable energy credits (RECs) that are Green-E certified. Noting that they are “taking advantage of more cost effective and cost competitive REC prices,” city officials contend that they have maintained a relatively flat power price while also increasing the percentage of renewable energy in the city’s portfolio. Houston has committed $2 million for the two-year agreement, less than a cent/kWh on top of the city’s power price. In addition to purchasing green power, Houston has been purchasing and building renewable energy projects, such as wind and solar.