Retrotec USACE - Manual (Page 61)

Chapter 5 39
The energy tariff analysis is necessary for fi nding the correct energy price
for the saving measures occurring at different times of the day, week, and year.
Typical questions for the analysis are
What are the elements in the tariff? Is there a difference in energy price ■
for day and night? For summer and winter? What are the fi xed costs?
How does the peak demand connect to the energy tariff? If there is a
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peak demand cost, could this be reduced by peak shaving?
Is there a reactive power charge?
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What are the main cost elements in the energy bill? Can peak shaving ■
or power factor correction (improving reactive power compensation)
reduce costs?
Are there alternative utility tariffs available?
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If energy conservation measures are implemented, how will the con- ■
sumption and peak demand change? What will the optimal tariff be in
the new situation?
Similar questions are valid for district heating and gas supply. When
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supply-capacity data is not available, the analysis must be based on cost
and energy data.
Typical questions for the analysis are
What are the elements in the tariff? Is there a difference in energy price ■
for summer and winter or other seasonal variation?
What are the fi xed costs? Do the fi xed costs depend on the peak heat-
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ing demand or something else?
What is the monthly cost and consumption profi le like? What is the dif-
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ference in the consumption between summer and winter months? If the
variation is not remarkable, the main consumption may be caused by
domestic hot water or system/network losses.
Peaks in heating demand occur between November and March. Other
peaks are caused by production processes or domestic or process hot water
use.
If there is a gas- or oil-fi red boiler, the boiler losses and other system losses
should be analyzed to calculate the actual amount of energy savings. The
energy assessment team will calculate the savings by looking at the consump-
tion side (savings in the energy use of an air handling unit or a heating system
in a building), but the total savings has to take into account the boiler and
system effi ciencies, and the report should show savings in input energy (fuel
or gas).
There may be saving possibilities in eliminating unnecessary heating or
unnecessary losses. For heating, the losses of the heat distribution may be a
critical issue.
Water may be a signifi cant cost issue in some facilities where the process
requires large quantities of water. Water may be heated for processes or for
domestic use, leading to a high demand for heating energy.