Quick Economics

Natural gas engine-driven air compressors significantly reduce, or may even eliminate, power demand and electric energy consumption cost for operating air compressors, and they use natural gas as the primary source of energy. It is easy to evaluate the preliminary economics of using these air compressors. The Quick Economics calculator allows you to estimate your own savings from deploying these air compressors for your own compressed air needs and energy rate schedule.

The calculator has been developed for making preliminary economic estimates using the following simplified input and assumptions:

• Average annual compressor usage
• Average gas, electric energy and demand charges
• Assumes full load operation
• Assumes 80% efficiency of the gas-fired device that is displaced by the recovered heat

For applications where compressed air is used in multiple shifts, more than the usual 5 days per week, and electric power demand and energy charges vary significantly with time of use, it is recommended that you calculate average electric rate before using the quick economics calculator.

The calculator estimates the following economic parameters:

• Total annual operating cost for gas-driven and electric air compressors
• Annual operating cost savings from using gas-driven air compressors
• Annual return on the capital cost premium for gas-driven air compressors
• Simple payback period for the capital cost premium for the gas-driven air compressor

The calculator estimates are only for the purpose of preliminary analysis and are based on the Air Compressor Advisor software (see next heading below), developed for the Energy Solutions Center. Detailed analysis must be performed for the specific plant application using operating conditions that match actual operations more closely, including part load operations and actual energy rates during each of the three production shifts.

The savings calculator Java applet will take about a minute to load at a modem speed of 28.8 Kbps. After loading the applet, its calculations and recalculations will be so fast that you might not even notice that new results have been computed.

Natural Gas Engine-Driven Air Compressor Advisor

The Natural Gas Engine-Driven Air Compressor Advisor is an analysis and reference tool intended to help with evaluation and selection of gas-powered air compressors. It is targeted for industrial applications and covers air compressors in the approximate size range of 50 to 500 horsepower.

The Air Compressor Advisor was developed by Energy International under the guidance of the Energy Solutions Center Air Compressor Consortium. Consortium participation has helped ensure that essential calculations are computed accurately by this powerful, yet easy-to-use economic decision analysis tool.

Results have been validated against several real-world examples.

The Air Compressor Advisor is organized into three sections: Manufacturers, Case Studies, and Economic Calculations. The Manufacturers section contains a database of company listings and product offerings (color photographs of products are included when available). The user has the ability to customize this database by adding, deleting, or modifying entries.

The Case Studies section contains several examples of sites that have benefited from the installation of gas engine-driven air compressors. Like the Manufacturers section, the user can customize the database by modifying, adding, or deleting information. The Economic Calculations section is comprised of two calculators: Quick Economics and Detailed Economics. The Quick Economics calculator allows the user to perform a quick screening to compare engine-driven and electric motor-driven air compressors. The Detailed Economics calculator allows the user to perform a thorough site-specific analysis by setting variables such as time of operation, part load efficiency, detailed gas and electric rates, capital or lease purchase criteria, and capital and maintenance costs.

For more information on the Air Compressor Advisor, click here to download a PDF file (212K) and a fax back order form.