THERMAL ENERGY STORAGE (TES) SYSTEM

     
Thermal comfort is normally the main reason of having an air conditioning system for a building. Other purposes include air circulation or ventilation, air purifying and dehumidifying or humidifying. An air conditioning system will consume energy and for a building in a hot and humid climate like Malaysia, the energy consumption takes up very high percentage relative to the overall energy usage.

A TES unit generally consists of a heat exchanger system of helical coils (metal or plastic) placed inside an insulated storage tank, a refrigerant tank, a refrigerant pump, and an air-cooled condensing unit. Being well insulated, these storage tanks (ice cell) can normally be located anywhere, either indoors or outdoors.

TES system is designed to work with the existing building’s cooling system (a chiller), which chills either water or an ethylene glycol solution for the heat-exchange air conditioning of the building. The system simply uses the chiller to make ice or chilled water during off-peak hours and stores it in the insulated storage tank.

Figure 1:  Schematic diagram for TES system

Figure 1 shows the diagram of the plant where AHU is air handling unit, FCU is fan coil unit, CT is cooling tower, PHX is primary heat exchanger and SHX is secondary heat exchanger.

Written By:

ABDUL HAFIZ BIN KASSIM

AHMAD IZZAT BIN MOD ARIFIN

MOHD SAIFUL NAJIB BIN ISMAIL@MARZUKI

OFF-GRID SYSTEM

The standalone PV system which is also known as an off-grid PV system is one of the types in the photovoltaic system. The characteristic for this type is its independence of grid supply. Usually the system is installed in remote area.

Many PV systems are used to energize remote homes, facilities, and devices. An example of an off-grid system includes a remote solar home. Military communication units with supplemental solar and wind are also off-grid. Monitoring or communications devices are also of off-grid type. Energy is gathered from solar modules and is directed into energy storage devices for use when needed. These systems often supply the entire amount of energy required.

Usually the standalone system shown in Figure 1 consists of 4 main parts which are the PV module, the charge controller, the battery storage and the load. Not all the standalone systems require the inverter. The inverter converts the DC voltage into the AC voltage. The inverter depends on the load. If the AC load is used in this system, the inverter is also needed in this system or vice versa.

 Figure 1: Offgrid solar system source: affordable-solar.com

This system can be classified further into two types of standalone PV systems which is shown in Figure 1 and hybrid PV system whch is shown in Figure 2. Basically the standalone system is small in size and battery-operated. Hybrid system is of medium size and has PV module and Generator set or other power generators.

Figure 2: Hybrid Off-Grid PV System Schematic

Written By:

AHMAD IZZAT BIN MOD ARIFIN

MOHD SAIFUL NAJIB BIN ISMAIL@MARZUKI

ABDUL HAFIZ BIN KASSIM

ON-GRID PV SYSTEM

ON-GRID PV SYSTEM

In general on-grid PV system has its own characteristics. Most modern PV systems are grid-connected as shown in the figure below. The electrical energy is directed into the existing municipal power grid. Energy is effectively stored in the grid. When a grid-tie system generates more than energy needed, the electrical meter turns backwards. Many large arrays are intended solely for use as power plants, as well enhancing or supplanting the need for conventional power plants. The grid application systems do not need large batteries. The PV grid-connected system is also called grid-interactive, grid-intertie, utility connected which is built onto your building that transfers DC power from the PV array to the utility supply (TNB) through grid-inverter.

 On-grid PV System

Written By:

MOHD SAIFUL NAJIB BIN ISMAIL@MARZUKI

AHMAD IZZAT BIN MOD ARIFIN

ABDUL HAFIZ BIN KASSIM