Builders immediately score higher in the environmental section of the scoring system if they build their own power supply generated by natural gas. Second, natural gas power generation is approximately 7% to 8% cheaper than the energy provided by the national (coal-driven) power system. The savings in cost reduces the cost of producing the desalinated water, thereby raising the bid-score further (since cheaper water scores higher). Builders are permitted to build a power facility that exceeds the required power for the desalination process.