Free
energy savings
In the October
2007
newsletter, I gave you information about remote tuning up of
refrigeration plants. The initial step of this tuning up is free. I have been
asked many follow up questions about free energy savings, and I will give you
additional information about this issue.
Remote tuning up of refrigeration
plant does not require an initial visit to the plant. This approach eliminates
the necessity of upfront investment for the initial visit of the consultant.
Usually, I send a questionnaire to chief engineer (supervisor) to get
information about equipment and about operating set points. Than I review this
information and suggest to him the necessary steps to improve efficiency of the
refrigeration plant. The first few steps are simple and do not require
significant effort from me or from the chief engineer (supervisor). This is the
reason that the initial step of tuning up is free. Typical annual energy savings
of this step are $ 10,000 - 40,000 (average $
25,000). Acceptable payback on investment in energy efficiency in
industrial refrigeration is 2 years. The average plant can
save $ 25,000 of energy costs or $ 50,000 of
investment in energy efficiency. Surprisingly, the cost of saving $
50,000 of investment is less than $ 1. Do you know
anybody else who can save you $ 50,000
without any investment? May be this free energy
savings looks too good to be true, but you have the opportunity to test this
approach.
How do you make money? Several times
I was asked this question. Usually, optimization of average refrigeration plant
can save $ 80,000 - 100,000. The first $
25,000 of this energy savings is free. The cost of the rest of the
energy savings is not free, but payback for the remaining steps is a few months.
This payback is 10 - 20 times shorter than acceptable in our
industry (2 years
),
because optimization of refrigeration plant operation is the best way to save
energy.
Example of
refrigeration plant free tuning up.
Minimum allowable head pressure for
refrigeration plant is 120 psig . This
plant has 6
different high stage screw compressors. These
compressors have liquid injection oil cooling. This oil cooling is a major
barrier in reducing the head pressure.
High stage screw compressors have
different sensitivity to low head pressure. For winter operation, this plant
requires only 3 high stage compressors. We can choose
3
compressors (less
sensitive to low pressure) and run them during winter operation. Head pressure
can be lowered to 110 psig. For this plant, every 1
psig of
lower head pressure will save $ 2,000 per year in energy costs.
Total annual energy savings from choosing the right compressors will be
$ 20,000 . The other 3
compressors will be the leading machines during
the summer operation.
I believe in
smart and efficient operation of refrigeration plants. Optimization of
refrigeration plant operation is the best way to save energy. You have the
opportunity to test the best approach in energy savings, and this test is free.