Emerging Technologies for Industrial Demand-Side Management

Demand-side management (DSM) is a set of actions taken by an electric utility to influence the electricity usage by a customer. Typical DSM activities include rebates for higher efficiency appliances and discounted electric rates for electric customers whose service can be interrupted on short notice. This paper explores two more subtle DSM activities: using turbine "let-downs" and thermal storage. High efficiency and adjustable speed drive (ASD) electric motors have long been considered as demand-side management strategies for industrial consumers of electricity. An alternative strategy to replacing aging electric motors with high efficiency or ASD motors is a turbine let-down. A turbine letdown is a turbine which uses pressure reduction to produce useful work. A typical application of this type of turbine would be to replace both a pressure reducing device and an electric motor driven pump. Air conditioning is a primary contributor to peak electric loads in Texas. One of the ways to solve this problem is to move the loads from peak to off-peak periods without changing overall electricity consumption. By using cool storage systems, energy consumption for businesses and industry can be shifted, reducing electricity costs to the consumer and reducing the electric utility's need to build more power plants