in Australia to offer "householders energy efficiency incentives programs delivered via local electricity retailers." The British transmission system operator incentivizes off-peak use. Private implementation The negawatt market is being used by governments and companies. Aluminum manufacturers in the Pacific Northwest shut down their power plants and sold the unused energy because selling the negawatts was more profitable for the company than selling the aluminum product. This was possible because "The smelters hold power contracts with the federal Bonneville Power Administration that contain clauses allowing them to market the electricity." The Associated Electric company in rural Missouri is implementing the usage and spreading the knowledge of negawatts by performing energy audits at their customer's homes to show them where they could be saving electricity. Rebates are being given to help customers pay for more energy-efficient, Energy Star appliances. Keith Hartner, the CEO of Associated Electric Cooperative Inc., feels that negawatts are generating savings for their customers and for the company as well: “The goal of this program is to save money not only at the generator but also at the meter for the members.” Individual households can practice negawatts through using energy-efficient lighting and Energy Star appliances as well as simply reducing standby power. The resulting savings sometimes offset the investment in new high efficient light bulbs and appliances. These efficiencies can offset a portion of the cost of a residential photovoltaic system. Negawatts reduces the overall size of the photovoltaic system required for the household, because they are consuming less electricity. This results in a faster payback period for the photovoltaic system. The City of San Diego has created a negawatts initiative called "Reduce then Produce" to promote this idea. Advantages Cost The most noteworthy advantage in creating a negawatt market is the cost incentive. As many will say, "The cheapest watt is the one that's never created." In this market, the consumers who increase their home efficiency, or decrease their energy consumption, can earn money by selling the saved electricity. This is similar to an emissions trading or a cap-and-trade system, in which the energy that is not used can be bought from the consumers who saved the energy and sold to those who need to purchase the extra energy. Providers of electricity can encourage consumers to sell back their unused energy, or negawatthours, especially during peak hours. A major question that electric companies need to ask themselves is