With an abundance of lakes and rivers, New York State has used the power of water since before the 19th century. The state's first gristmill was constructed in 1788 outside of Poughkeepsie, NY and utilized a simple waterwheel to grind grain into flour, as mentioned in the Poughkeepsie Journal. Now, New York uses waterpower to generate 20% of its electrical needs with a network of more than 200 hydroelectric dams. According to the National Hydropower Association, these facilities provide New York with over 6000 megawatts of emission-free electricity each year while also supporting local economies and creating jobs. Hydro dams are particularly important in the North Country, as the inexpensive electricity attracts industrial development and continues to keep electrical rates low in the region. In addition, Community Hydroelectric Companies, such as Northern Power and Light, allow residents to source 100% of their electricity supply from locally produced, clean hydropower. New York is committed to providing low-cost, carbon-free electricity to its residents, and hydropower will continue to be a key energy source in the state’s future.
Present-day hydroelectric dams work much like historic gristmills in that both rely on mechanical energy provided by continuously flowing water. However, the United States Geological Survey shows us that hydro dams can convert this mechanical energy into electricity, ready to power our homes and businesses. Hydroelectric dams are constructed along a section of river that has a large drop in elevation, creating an upper reservoir containing the flowing water. Water from the upper reservoir then flows through a group of pipes, called a penstock, which runs through the dam. Inside the penstock are several turbines that are spun by the flowing water. The turbines are coupled to generators that produce electricity as the turbines rotate. Many hydro dams take advantage of a practice known as pumped storage to increase their energy output during hours of peak electrical demand. Pumped storage works by using excess electricity produced during low-demand hours to pump water from the penstock to storage pools located above the dam. During hours of high electrical demand, the water in the storage pool is released into the dam’s penstock and used to create electricity when it is needed most.
Written by: Nolan Rishe, Energy Advisor for St. Lawrence and Franklin Counties