WGL Holdings, a public utility holding company, markets and distributes natural gas and electricity throughout the United States, including Virginia, Maryland, and District of Columbia. The company also offers a variety of energy related products and services to customers, such as refrigeration equipment, and heating, ventilating and air conditioning solutions. Its subsidiaries include Washington Gas, Hampshire Gas, Washington Gas Resources and Crab Run Gas Company. Washington Gas Resources provides design, engineering, installation and service of electrical power equipment, plumbing and lighting systems, and automated energy control products. Washington Gas generates and sells electricity, and transports and distributes natural gas to over 1 million residential, commercial, and industrial customers. WGL Holdings is headquartered in Washington.