In this newsletter I
will give you information about my approach to energy savings. I have done
extensive research in energy efficiency of industrial refrigeration and I
believe that I have found a cost – effective way to save energy. Idea of my
approach is to save maximum energy with minimum investment. I believe that every
manager and every chief engineer is interested in this approach. Let me show you
the difference between traditional approach to energy savings and cost –
effective approach.
Traditional energy efficiency project
involve 2 steps:
- Energy audit to identify energy saving measures,
estimation of implementation of these measures and estimation of potential
payback. This step will give you direction of your investment to improve
efficiency of a refrigeration plant. Usually it will cost you from $ 5,000 to
$10,000.
- Implementation
of energy saving measures identified by energy audit. This step involve significant (commonly more than $100,000) investment
and has a payback, usually 2-3 years. You have to by expensive equipment
(PLC, VFD and etc.) to achieve energy
savings identified by mentioned audit. Make sure that you have optimum set
points and operating strategies to maximize efficiency of your refrigeration
plant.
I am proposing a cost – effective
approach to improve efficiency of refrigeration plants.
This approach involves 3
steps:
- Housekeeping. Energy efficiency actions are done by
operating engineers of refrigeration plant, based on their knowledge and
experience. It is a very good first step to energy efficient refrigeration
plant, because you just have to encourage your engineers to save energy.
Typical savings at this step are 5-10 %. Payback is less than 1 month.
- Low cost investment. Energy efficiency actions are done by
consultant to improve efficiency of existing refrigeration plant without major
capital investment. This step involves an optimization of operating strategies
and operating set points. Typical savings at this step are 8-12 %. Payback is
usually 1-2 months.
- Retrofitting.
Investment in energy saving equipment (PLC,
VFD and etc.) can save you additional 10 % of your energy use. Payback is
typically 2-3 years.
Every step in this process will be more
and more expensive. At step 1, you probably have to pay just bonuses to your
engineers. At step 2, usually your expenses are only a consulting fee. Payback
at this stage is 1-2 months, because this fee is commonly around 10 % of total
cost for energy efficiency project. At step 3, you have to buy energy saving
equipment. Choose the right set points and right operating strategies to
maximize efficiency of this equipment; otherwise you will not get energy savings
that were expected.
I believe that step by step improvement
of efficiency of refrigeration plant is much better approach, because first two
steps have very short payback and only at last step significant capital
investment is required.