16,261 MW, and Alberta has about of transmission lines. Alberta has 1491 megawatts of wind power capacity. Production of electricity in Alberta in 2016 by source: Alberta has added 9,000 MW of new supply since 1998. Peak for power use in one day was set on July 9, 2015 – 10,520 MW. Mineral mining Building stones mined in Alberta include Rundle stone, and Paskapoo sandstone. Diamonds were first found in Alberta in 1958, and many stones have been found since, although to date no large-scale mines have been developed. Manufacturing The Edmonton area, and in particular Nisku is a major centre for manufacturing oil and gas related equipment. As well Edmonton's Refinery Row is home to a petrochemical industry. According to a 2016 Statistics Canada report Alberta's manufacturing sales year-over-year sales fell 13.2 per cent, with a loss of almost four per cent from December to January. Alberta's economy continued to shrink because of the collapse of the oil and gas sector. The petroleum and coal product manufacturing industry is now third— behind food and chemicals. Biotechnology Several companies and services in the biotech sector are clustered around the University of Alberta, for example ColdFX. Food processing Owing to the strength of agriculture, food processing was once a major part of the economies of Edmonton and Calgary, but this sector has increasingly moved to smaller centres such as Brooks, the home of XL Foods, responsible for one third of Canada's beef processing in 2011. Transportation Edmonton is a major distribution centre for northern communities, hence the nickname "Gateway to the North". Edmonton is one of CN Rail's most important hubs. Since 1996, Canadian Pacific Railway has its headquarters in downtown Calgary. WestJet, Canada's second largest air carrier, is headquartered in Calgary, by Calgary International Airport, which serves as the airline's primary hub. Prior to its dissolution, Canadian Airlines was headquartered in Calgary by the airport. Prior to its dissolution, Air Canada subsidiary Zip was headquartered in Calgary. Agriculture and forestry Agriculture In the past, cattle, horses, and sheep were reared in the southern prairie region on ranches or smaller holdings. Currently Alberta produces cattle valued at over $3.3 billion, as well as other livestock in lesser quantities. In this region irrigation is widely used. Wheat, accounting for almost half of the $2 billion agricultural economy, is supplemented by canola, barley, rye, sugar beets, and other mixed farming. In 2011, Alberta