Energy Generation Alternatives

• Introduction
• Cogeneration
• Alternative Electric Generation
• Evaluating the Business Case
• Conclusion

Introduction

Utilities for a facility or campus can be classified as electric, thermal for space conditioning, thermal for process requirements, water, and sewer. The thermal classes comprise cooling as well as heating components.

Choosing to supply a utility from a central production station arises from the expectation that economies of scale in equipment, real estate, labor, and operations from a central operation outweigh the inefficiencies of the distribution system and any required local converters. Electric, water, and sewer utilities are the classic examples of this approach on the regional scale. On the campus scale, central plants can provide similar advantages for the thermal utilities of chilled water, hot water, and steam.

Another potential increment of efficiency in central plant operations can be extracted by the production of useful mechanical and thermal energy from the same fuel source, or cogeneration. Typically, mechanical energy is used to turn an electric generator, while the recovered thermal energy is used to generate steam and/or hot water. When there is a suitable need for one or more hot thermal utilities, in terms of both instantaneous demand and consumption over a period of time, cogeneration can be an economical option.

This section begins with an overview of the regulatory enablers for self-generation. A discussion of the opportunities for electric energy generation follows. Cogeneration systems are emphasized, with supplementary information on photovoltaics and wind turbines. The section concludes with factors important for evaluating the financial aspects of a self-generation project.