Energy management Systems

 Energy management Systems
Summary
Energy management system was learned and implemented using a computer and a
simulator. Total energy demand for 24 hrs was determined using this system with different
values of the ambient temperature. Also adaptive optimum start control and adaptive maximum
demand control were implemented using this energy system. It has been found that this system
works well in managing the demand of the two offices and a workshop, leading to significant
savings in energy consumption.
Introduction
Electricity saved is equal to electricity produced. Until a couple of decades ago this
statement was of economical significance only. However, in the present day when the harmful
effects of green house gases and global warming have become so obvious and are also some of
the most serious challenges facing the humanity today, this statement is of great significance
from environmental consideration.
Needless to say that today there is a great thrust on electricity conservation from
economical as well as conservationist and environmental considerations. Fortunately,
advancement in technology has provided us with great tools to manage the consumption of
energy in a much better manner than that in earlier days. If such energy management systems are
optimally used, then wastage of energy can be minimized to a great extent resulting in
significant savings in energy consumption.
Instead of the conventional approach to turn on and off lighting, heating and other energy
consuming devices as per a set pattern, one can implement an energy management system in the
premises ( residential / office / industrial). Such an energy system turns on and off the energy 
consuming devices as per the demand management. Such a system remotely acquires data from
the field into the central computer, displays the relevant data so and sets values and has even
alarm to help the manager intervene if required and turns on / off the energy consuming devices
as per the actual demand by sending suitable signals from the central computer itself to the
relevant energy consuming devices as per the algorithm of the energy management system.
In this manner energy management system works to optimize the consumption of energy
and save the energy by cutting down on wastage of the same. Energy management systems can
also be utilized for effective exploitation of natural energy resources like solar energy in Arabian
countries. Islam et al (511) have carried out measurement of solar radiation in UAE so that this
resource can be utilized in an optimum manner. They have reported existence of very high solar
energy flux and clear sky condition in UAE throughout the year. This means solar energy can be
effectively harnessed in UAE.
Energy management systems can be either dedicated or comprehensive. A dedicated
energy management system is suitable for one particular building or plant items. However the
comprehensive energy management system manages a collection of dedicated energy
management systems.
An energy management system can incorporate one or many of the following
functionalities:
Temperature: Heating, ventilation, hot water, burner controls etc.
Electrical power: Machinery, office equipment, heating, fans etc.
Lighting controls: Timer, ambient light level sensor monitors
Plant operation: combustion efficiency, process control…
…Results
Results from Simulation – 2, about energy consumption in 24 hrs cycle for different
values of external temperature in 0 oC to 20 oC under different circumstances of insulation and
solar gains is presented below in Table 1. From this table it can be seen that the value of total
energy consumption in 24 hr cycle decreases with increasing external temperature. The value of
total energy consumed in 24 hr cycle also decreases if proper insulation is there. Gains from
solar energy are also considered.
Table 1: Energy Consumption in 24 hrs Cycle
Exte
rnal
Temperature
(
oC)
Energy Consumption (kWh)
Without
Insulation or solar
gain or wind and
other losses
With Wall and
Ceiling Insulation but
without Solar Gain and
Wind and Other Losses
With Wall and
Ceiling Insulation and
Solar Gain and Wind and
Other Losses
0 36 30 27
5 33 27 24
10 27 22 19
15 20 18 17
20 15 12 12
The plot showing variation of total energy consumption in 24 hrs cycle with external
temperature under different circumstances is shown in Fig. 1, below…
…References
Y.P. Cai, G.H. Huang, Z.F. Yang, Q. Tan., “Identification of optimal strategies
for energy management systems planning under multiple uncertainties”, Applied Energy
86 (2009) 480–495
M.D. Islam, I. Kubo, M. Ohadi, A.A. Alili, “Measurement of solar energy
radiation in Abu Dhabi, UAE”, Applied Energy 86 (2009) 511–515