Assessment of Non-electric Cooling Alternatives to Reduce the Electric Demand of New York's Power Grid

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Electric cooling technologies impose significant demand on the utility grid. For instance, the cooling system for a 200,000 square foot building can add over 300 kW of electric load onto the grid during peak summer periods. A typical 600,000-square-foot building has an electric chiller plant that peaks at nearly 1 MW. Natural gas and steam chillers, on the other hand, impose only a fraction of these loads on the electric grid. This article highlights the potential and importance of subsidies and incentive programs in promoting non-electric cooling technologies to help reduce the peak demand load on the New York power grid. The results obtained also provide valuable equipment-installed costs and energy/demand parameters for both electric and non-electric chillers. The technical and economic viability of five non-electric cooling technologies are compared to standard practice electric chillers. The five non-electric cooling technologies are: 1. Gas engine-driven chiller 2. Two-stage gas-fired absorption chiller 3. Two-stage steam-fired absorption chiller 4. Single-stage steam-fired absorption chiller 5. Steam-turbine driven centrifugal chiller The energy consumption and peak summer demand were calculated for the chillers in each of three different size ranges. Installed cost estimates were developed for each chiller technology in two regions of New York State. The results presented here will help design consultants, estimators, utilities, and government energy officials assess preliminary estimates for installed costs, energy savings, and incremental maintenance costs. Normalized costing indices such as $/ton, $/hp, $/sqft. and $/lin.ft and operating characteristics such as full load hours and kW/ton rules of thumb for the chiller and plant components are also presented. The study reports typical office building savings and economic paybacks. Chiller operation of 800 equivalent full load hours (EFLH) for upstate New York sites and 850 EFLH for downstate/NYC sites were used.