Energy Management Strategy
What is the right energy management strategy for your air compression needs? The answer depends on your production requirements (annual operating hours, compressor capacity, etc.) and natural gas and electric energy rates.
There are a number of important considerations in selecting air compression equipment, but the bottom line is its impact on the economics of your operation and investment. With today’s volatile energy markets, there is no clear path forward. However, there is ample evidence that installing electric / gas hybrids for air compression service makes the most sense over the economic life of the equipment.
The following factors affect an energy management strategy:
- Costs of gas and electric energies for Operation (see tables)
- The cost of lost operation due to power failure causing your air compressor to shutdown and stopping production.
- The capital cost of additional electric generating backup required for motor-driven units.
- The future cost of peak power
- Natural gas engine maintenance schedule
Basic energy management strategies depend on the mix of equipment installed. General operating rules follow common sense:
- Operate gas units during peak and mid-range electric pricing
- Cogenerate air and thermally recovered heat when economically feasible
- Operate hybrid systems when production value is high and onsite generation is expensive.
Installing Electric/Gas Hybrids
Electric Peak Shaving with Gas Engine-Driven Air Compressors
Power costs vary hourly depending upon system demand and the availability of generation assets. Larger customers often pay time-of-use (TOU) rates that convert these cost variations into daily and seasonal rate categories — such as on-peak, off-peak, and shoulder rates. TOU customers and those competitively acquiring power could select distributed generation during high-cost peak periods and reduce their overall cost of power. The electric supplier in turn may be able to reduce the amount of high-cost power purchased during system peaks.
Electric Air Compression System
The hourly chart depicted below represents a three-shift operation with peak air compression operations between the hours of 12:00 noon and 6:00 pm. The green area represents electric demand for air compression during off-peak times, the blue area during mid-peak times and the red area during on-peak operation. The yellow area represents the ideal electric demand to be displaced with a natural gas engine-driven air compressor.
The natural gas engine-driven air compressor shifts the electric peak load to natural gas. The result is a dramatic shift downward in electric energy use and cost for producing compressed air.
The final outcome being the electric load profile for air compression depicted below.
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