Energy management in industries is vital, to reduce operating costs and prevent wastage of energy resources. This can be done with the help of IoT (Internet of Things). The speaker for this conference program was Mr. Vinayak Patilkulkarni, Chief Technology Evangelist, Invendis Technologies. Invendis Technologies deals with the remote monitoring of mobile towers to ensure continuous and efficient operation, as well as reduced energy costs. He gave a brief outline of the requirements for an energy management plan. The most important point is that the power supply should be uninterrupted. Also, in the case of a mobile tower, several mobile operators may be using a single tower. It is important to know the exact power consumption of each operator, because each operator will use energy differently.
Tower energy sources
Power can be supplied to mobile towers in multiple ways. This includes power from the grid, which is the utility power. There are also battery banks and fuel cells that can be installed to provide power to the towers. From the renewable energy point of view, wind and solar energy can also be harnessed. Ideally, a combination of all these sources of energy can be used, to provide power continuously. For example, if the grid fails, batteries can be used as a backup.
Energy source characteristics
“When we say we will do energy management, we need to understand a little bit about the characteristics of this energy source. In a typical Western country, utility power is very stable, always available, but in lot of developing countries, it is not always the case. For maybe four to six hours, you do not have grid power, maybe in some countries, for 20 hours you do not have grid power, so you are kind of relying on other energy sources to essentially drive power to your tower,” said Mr. Patilkulkarni. One of the most important characteristics of an energy source is reliability. A diesel generator offers good reliability and long hours of operation. However, it requires a lot of maintenance and manual filling of fuel, which makes it slightly inconvenient. Solar and wind energy are dependent on environmental conditions, so the energy needs to be stored before supplying it to the mobile tower, to ensure a continuous supply of power. When it comes to a low maintenance energy source, battery packs are a suitable option. The disadvantages are that they need to be recharged from time to time, and their efficiency is dependent on ambient temperature.
Energy measurement is very important for proper energy management. In the case of a mobile tower, operators use different kinds of energy, in different quantities, and hence the details of energy usage for each operator needs to be measured and recorded. This can be done with the help of smart energy meters. A hub can be used to collect the information coming from the various smart meters and perform certain computations using the data. If there is an issue that needs to be dealt with, such as a problem in one particular phase, the hub will send a message to the cloud, which will alert the technical operators who are in charge of the towers. They can take action depending on the issue.
“The hub is like the central figure in the solution, where a lot of data gets connected. The very first things that we are actually connecting here are smart meters. We won’t really be connecting physical meters, because lot of them are nowadays multi-channel, so a single actual meter can measure three or four channels of data. If you have tower equipment that is connected to three channels, you could connect one meter and measure all the three values of voltage, current and power.” These smart meters provide information about the share of energy supplied by the diesel generator, grid and battery, and also calculate the amount of energy used by each operator. After all this data is collected, a cost breakup can be obtained to find out the areas of highest expenditure. Decisions can then be made, regarding whether the diesel generator or the battery should be used more.
Monitoring energy source parameters
The energy sources need to be monitored continuously to ensure that they are functioning properly at all times. So, sensors are used to monitor the various energy sources. For a battery pack, the efficiency depends on the individual performance of each battery. The characteristics of each battery need to be recorded, along with the power that is delivered by the entire battery pack. In the case of a diesel generator, the fuel consumption needs to be continuously monitored, and this can be done with the help of fuel sensors. Diesel generators also have a controller, and that can be monitored to obtain information about the functioning of the generator. This is used to find out when the grid fails and when the generator takes over.
Battery management is essential
To find out whether the battery is functioning as per its specifications, certain parameters can be monitored, such as current, voltage, impedance, and state of charge. Another factor that needs to be monitored is the charge cycles of the battery. This will provide information about the remaining battery life. There is also a parameter called state of health (SOH). It includes information about the charging time of the battery, and whether the battery is charging to 100 percent or not.
Diesel generator performance needs to be tracked
The diesel generator needs to be monitored to keep track of its health and performance. Fuel sensors are used to check fuel levels and usage. The sensors can also send out alerts to remind the user to refill the generator. Since the diesel generator has a running motor, preventive maintenance is also needed. This can be done by remotely recording the amount of time for which the generator has been in operation, and based on that information, if the generator has been running for too long, it can be switched off to prevent any damage to the equipment.
Certain energy sources, like battery packs, function differently based on the environmental conditions. Thus, the environmental parameters need to be monitored. “Battery requires temperature to be stable, at 17-18 degrees Celsius, so you would have to turn on the air-conditioning if the ambient temperatures are high, or if you have some other free-cooling solution that is there, you have to ensure that it is controlled. Electrical equipment is sensitive to humidity, so you have to measure that as well. Then, of course, smoke and fire is important. You need to monitor for that, because if you are able to detect it, you have a chance of saving some of the equipment,” said Mr. Patilkulkarni.
He gave the audience a brief overview of the entire solution for energy management. “You have monitors, for equipment, you have meters that are delivering energy data, you have sensors that are monitoring environment and the hub is basically acting like a data acquisition engine, as well as a computing and control engine, which is sending data to the cloud, and you are doing some analytics and reporting at that end.” Analysis of the information from all the sensors will lead to better preventive maintenance and replacement cycles can be predicted.
Leveraging the IoT evolution
To be able to utilise IoT for energy management, certain factors need to be kept in mind. Mr. Patilkulkarni mentioned that there should be a complete transition from wired to wireless devices. There needs to be a common information and control model, which can be used in all systems. “From our point of view, we are looking at building solutions, whether it happens with sensor X or sensor Y is not really the issue. We want to be able to build solutions that adapt to different requirements. We really need interoperability in terms of sensors and platforms. So then we are able to take these things and do this service delivery at cost-effective price points,” he said.
He concluded his talk by saying that the IoT industry needs to evolve in such a way those solutions for energy management can be provided in a quick and cost-effective way.
Watch Mr. Patilkulkarni’s talk at the India Electronics Week 2016, here:
03_Improved Energy Management for multi energy-source deployments using IoT.mp4 from EFY on Vimeo.