本文概述了水系统的替代能源，并介绍了从传统能源中节约能源的方法。讨论了主动和被动太阳能系统、光伏电池和风力发电等替代能源。介绍了天然气、电力和石油的比较成本。讨论了在分配和泵送系统中节能的方法，包括打开阀门、降低工作压力、减少管道摩擦、运行泵、匹配泵曲线、使用节能电机、在夜间填充高架存储设施、使用变速泵以及使用计算机控制来利用夜间电力成本。 水处理厂的节能方法包括:平衡供暖、通风和空调系统；安装高效照明设备；设计处理厂时考虑处理组件的能源需求；尽量减小水力梯度；使用能耗低的凝固剂；使用干砂床或污泥脱水和干燥池代替能耗高的污泥脱水设备；使用带有倾斜漏斗底部的沉淀池；使用能源密集型颗粒活性炭过滤的替代品来减少三卤甲烷；使用计算机监控常规过滤器的反冲洗； 采用高位储存反冲洗水；提升clearwell以降低过滤系统的过滤速率；使用化学分析仪，防止化学剂量过量；尽可能使用重力流系统。包括参考、表格、数字。

This article provides an overview of alternative sources of energy for water systems and presents methods for saving energy from conventional sources. Alternative sources of energy such as active and passive solar systems, photovoltaic cells, and wind power are addressed. Comparative costs of natural gas, electricity, and oil are presented. Methods of saving energy in distribution and pumping systems relating to opening valves, reducing operating pressure, reducing pipe friction, running pumps, matching pump curves, using energy-efficient motors, filling elevated storage facilities at night, using variablespeed pumps, and using computer controls to take advantage of nighttime power costs are discussed. Methods for saving energy in water treatment plants addressed include: balancing heating, ventilating, and air conditioning systems; installing efficient lighting fixtures; designing treatment plants with consideration for energy demands of treatment components; minimizing the hydraulic gradient; using coagulants that require low energy expenditures; using sand drying beds or sludge dewatering and drying lagoons instead of energy-intensive sludge dewatering equipment; using sedimentation basins with sloping hopper bottoms; using alternatives to energy-intensive granular activated carbon filtration to reduce trihalomethanes; using computers to monitor backwash for conventional filters; using elevated storage for backwash water; elevating the clearwell for declining-rate filtration systems; using chemical analyzers to prevent overfeeding of chemical doses; and using gravity-flow systems whenever possible. Includes reference, table, figures.