Westar Energy is the largest electric utility in Kansas. Westar provides electric generation, transmission, and distribution services to approximately 687,000 customers in Kansas. Westar Energy provides these services to central and northeastern Kansas, while its wholly owned subsidiary, Kansas Gas and Electric Company, provides these services to south-central and southeastern Kansas. The company has has 6,756 megawatt of generating capacity in service. In 2010, it had $203 million of profit off revenues of $2.1billion. 
Westar is looking to grow by diversifying its energy supply portfolio and building new transmission lines. Westar had built a 345 kV transmission line in central Kansas and is building a 50 mile 345 kV transmission line in south central Kansas. Westar is also looking to invest in wind energy and has developed 300 MW of wind generation facilities at three sites in Kansas. One of Westar’s joint venture companies is Prairie Wind Transmission,
The electric utility business depends heavily on the weather. Electric sales are seasonal and changing weather affects the amount of electricity use. Hot summer temperatures along with cold winter temperatures increase demand among residential customers. Residential customers accounts for 35% for Westar’s revenues.
During the third quarter of 2010, Westar benefited from warmer than normal weather. Weather was 63% warmer than the same period in 2009 and 20% warmer than the 20-year average. This key factor led to increased retail electricity sales for Westar.
EPA regulation on a number of different fronts will increase costs for electric utilities. In May 2010, an EPA regulation known as the tailoring rule allowed the EPA to regulate greenhouse gas emissions from stationary sources. This regulation follows two Federal Clear Air Act programs. In addition to greenhouse gases, EPA is also regulating coal combustion byproducts. During the operation of electric utilities coal generation plants, coal combustion byproducts are produced. In July 2010, EPA published a proposed rule in the Federal Register to regulate CCBs. There has been another proposal to further decrease nationwide mercury emissions.
Westar estimates that the cost of compliance for new environmental equipment from 2011 through 2013 will be $429.1 million.