CONSERVING GALLONS AND KILOWATTS: CHALLENGES OF TODAY'S SOLAR POWER PLANTS - AN EPC PERSPECTIVE

摘要

With the increasing restrictions on CO_2 emissions, the utilization of solar power is emerging as an effective way to increase the renewable portfolio for utility power. For example in California, the utilities' current renewable portfolios must increase from 20% to 33% by 2020. This drive has made renewable power considerably more desirable. However, fresh water availability and optimal solar irradiation are generally two mutually exclusive local characteristics that make locating and designing these plants challenging. Not only is fresh water scarce at the desert locations where these solar plants are generally located, but options for disposal of wastewater can be very limited as well. These factors have pushed the design of these plants to develop a fine balance between conserving and reusing water to the greatest extent practical and reducing parasitic electrical loads. This paper will address the challenges associated with developing solar power plant designs that optimize house electrical load while minimizing water footprint. Through the, implementation of operational water management techniques and optimized water treatment processes, water usage can be reduced to manageable levels. Utilizing systems that recover and recycle wastewater, the system can be further optimized to reduce the overall water footprint. Case studies will be presented for multiple sites detailing the individual optimization required based on the water quality provided. Lessons learned during plant siting and permitting will be provided to shed light to the current issues associated with wastewater disposal in these areas and utilization of evaporation ponds. In addition, various design philosophies will be discussed to guide the reader through the difficulties of determining the right mix of initial capital cost, .optimized water usage, minimized operating cost and minimized parasitic electrical load.