Mahidol University Energy Management
Electricity consumption of Mahidol University, Salaya Campus is composed of electricity used for classroom teaching, medical services, other services, as well as activities operation of the university. These activities lead to high level of annual energy consumption. Mahidol University focused on energy management for effective energy consumption and sustainability. It also reduces wasteful energy and promote the reduction of greenhouse gas emission. Therefore, we promote and support renewable energy either solar energy or applied biodiesel including energy technology used in operations. This is to drive Mahidol University as an eco-university and sustainability, and to achieve Target 7: Affordable and Clean Energy, and Target 13: Climate Action.Energy) และเป้าหมายที่ 13 การรับมือกับการเปลี่ยนแปลงสภาพภูมิอากาศ (Climate Action)
Digital Power Meter
In 2021, Division of Physical Systems and Environment has installed 76 sets of Digital Power Meters: Automatic Meter Reading (AMR) to divisions of Mahidol University, Salaya Campus. This meter exports data automatically to invoice registered units. The meter does not only have less human errors in data registration, but also reduces the hiring expense on employees of Electricity Authority. There is a website where the electricity consumption information of installed locations is displayed. Therefore, divisions of the university can implement the information to analyze in electricity consumption reduction of divisions of the university received 22 kV distribution system in Mahidol University, Salaya Campus in the future so that this can be effectively and systematically used. This ensures that energy management follows the objectives of Mahidol University. Divisions of Mahidol University can visit the website to check electricity consumption information at
Digital Power Meter System (Automatic Meter Reading: AMR)
Processes of Digital Power Meter System (Automatic Meter Reading: AMR) contain 4 parts as follows:
1. Hardware
1.1 Meter
1.2 Measure device (CT – VT)
For hardware functionality, the meter record energy consumption in real-time every 15 minutes
2. Communications
2.1 Switch Hub
2.2 Media Converter
Communications transmit energy data recorded by the meter to server, and check current meter status connected to AMR.
3. System
3.1 Asset Management
3.2 Data Collection
3.3 Device Control
3.4 Data Delivery
System receives energy data recorded by the meter to process calculation management of electricity bills management for invoice preparation. This data of actual energy consumption is displayed on the university website.
4. Integration
4.1 Billing
4.2 Scada
4.3 Reporting
Function of integration receives report management and approval from administrator to invoice to relevant divisions for electricity monthly bills. The reports are stored for divisions to take energy consumption information.
Solar Energy
Mahidol University has developed energy management guideline in 2015. After that, solar energy has been installed to use for power supply in the buildings of the university. This supports low carbon society which responds to the university policies as an eco-university, and reduces the university’s electricity expenses. Electricity power produced from solar energy installed on the buildings is applied to equipment and appliances in the buildings, for example, air-conditioning, electric lamp, computer, etc. There are two systems of solar energy installed in Mahidol University.
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1. Off-grid Solar Energy System
Off-grid solar energy system has been installed at Mahidol Learning Center: MLC, and Mahidol University Bus Terminal. The maximum capacity is 1.3 kW with Polycrystalline solar cell panel which is able to produce electricity power even in low light. The power capacity per panel is 310W of a total of 4 panels, and 4 of 200Ah batteries for power supplies when there is no sun light. This system of solar energy is electricity system which does not connect to the main electricity of the building. Power will be stored in batteries which can be used for the whole day for staff and students working in and using Mahidol Learning Center and Mahidol University Bus Terminal. Portable electrical equipment, mobile phone, laptop, and power bank, can be charged.
Solar energy system is able to produce a total electricity power of 202.7W since it has been installed.
1) Mahidol Learning Center: MLC 14.3 W
2) Mahidol University Bus Terminal 188.4 W
2. On-grid Solar Energy System
On-grid solar energy system is a system used electricity produced from solar cell panels and electricity. The system has been installed at the Central Treatment Building, Mahidol University, Salaya Campus in 4 rai of land. In the areas, there are buildings, wastewater balancing tank, aeration tank, sedimentation tank, Chlorine exposure tank, supply building, and large machine which needs high level of power. An average electricity consumption is 28,000 units per month or approximately 112,000 baht per month. Solar energy system with a maximum capacity of 21.78 kW has been installed. A set pf 66 Monocrystalline solar cell panels which have a capacity of 330W has been installed. These solar panels have high efficiency in capacity more than Polycrystalline. The electricity produced by the system can be used for electrical equipment in the Central Treatment Building (activate at the same time) which are
- 24,000 btu air-conditionings 2 units
- 18,000 btu air-conditionings 2 units
- 55 inches television 1 unit
- 9.7 cubic foot refrigerator 1 unit
- 0.75 kW water pump 2 units
- 18W LED light bulb 30 units
However, exceed electricity capacity of Central Treatment Building produced by the system are distributed to machines in wastewater treatment system of the university to maximize benefits in consumption of renewable energy.
Solar Rooftop, Central Treatment Building, Mahidol University, Salaya Campus has distributed electricity since on 21 February 2021. The system produces electricity 80-100 units a day which can save electricity expense for approximately 10,000 baht per month. At present, solar panels system produces electricity to distribute to offices in the Central Treatment Building and the university 9.69 MWh per hour which is equivalent to carbon dioxide reduction of 3,798.67 kg or 113 trees in reforestation. If interested, please visit the website.
Essential equipment for off-grid and on-grid solar energy system
1. Solar Panel
2. Inverter
3. Battery
1. Solar Panel
2. Inverter
3. Control Cabinet
Functions of off-grid and on-grid solar energy system
1. Solar cell panels produce direct electrical current from the control system into the inverter when hit by sunlight.
1. When sunlight hits the solar cell panels installed on the roof, all of them would produce direct electrical current into inverter. Solar cell panels have the system which can monitor watt units produced by each panel.
2. Inverter changes direct electrical current into alternative electrical current for electricity distribution to the building which are device-charging table and batteries. Inverter of off-grid system does not connect to main power system or electricity to clearly separate the systems.
2. Inverter converts direct electrical current into alternative electrical current and transmit it to control cabinet after electrical current flow back to grid tie inverter. Inverter would have the system to restore data and track electricity energy data on website.
3. In case of insufficient sunlight or solar cells-produced energy, the system would apply electrical energy from batteries to function the devices
3. Control cabinet is a device to disconnect electrical energy distribution and to protect devices when it has short circuit. The electrical energy is used for electrical devices in the building. If there are more electrical energy than the need, the excess units will be distributed to other devices.
Mahidol University supports efficiency resources under the concept of reusing used oil from its food center as biodiesel renewable energy.
The biodiesel producing machine was installed next to Mahidol Learning Center: MLC, Mahidol University in 2017. The Mahidol Learning Center is a common area of the university where it has food center with capacity of over 1,000 people. This makes the food center produces a lot quantity of oil from deep fried food.
Producing biodiesel from cooking oil is reusing used oil to process with transesterification mixing with mixers until it becomes biodiesel. One liter of biodiesel production process costs 20-24 bath, which is used for truck transport in the campus. According to the success in making biodiesel used in the university, this will lead to knowledge sharing about biodiesel to community.
Processes of biodiesel production
1. Filtrate 50 liters of used oil in the filter tank
2. Filtered oil is pumped to the reaction tank and needs to be dehumidified by boiling at 110 ºC for 30 minutes. Then, wait for the oil to cool down to 50–55 ºC กน้ำมันให้เย็น จนกระทั่ง น้ำมันมีอุณหภูมิ 50–55 ºC
3. Prepare chemicals for making biodiesel in the mixing tank by adding 10 liters of methanol (20% of oil volume). After that, adding 600 grams of potassium hydroxide (1.2% of oil volume) into the tank, stir, and release it into the reaction tank.
4. The reaction tank has filtered oil and mixed chemicals (methanol + potassium hydroxide) at the temperature of 50-55 ºC and stir for 10 minutes
5. After the oil has been layered overnight, the biodiesel (clear yellow) and glycerin (dark brown) would be separated.
6. Clean the biodiesel (clear yellow) for 3-4 times, then dehumidify it again, let it cool down, and pump it to store in the last tank for biodiesel.
Biodiesel can be used for Mahidol University transportation which reduces environmental problems. This leads to knowledge sharing to surrounded community, and a sustainable system of used oil management.