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Sensors are important in environmental technology, because they are applied in numerous and diverse fields such as smart grids for optimum power distribution and usage, smart buildings and smart industrial process control. These are aimed at efficient resource utilization and therefore in reducing greenhouse gases along with other sources of pollution.
Integrated information and communications technology (ICT) is vital in providing solutions to current challenges in achieving clean technology. These rely heavily on the use of sensors.
Sensors measure a range of physical properties, and are therefore of varied types such as electronic sensors biosensors and chemical sensors. Sensors are most commonly designed to detect a signal and convert it into an electrical signal, thus interfacing between the physical world and the network of electrical and electronic devices like the computer.
Sensors make up the largest part in the commonly used wireless sensor and actuator networks that sense and respond to the environment, helping people and/or computers to interact with their surroundings.
Coal power plants generate almost 40% of global power but also produces high carbon dioxide emissions. Clean technologies are available to improve the efficiency of power systems, and sensors are essential to make these work. Sensors would help smart grids not just to track the source of power losses during distribution but also to decentralize power generation and integrate other renewable sources of energy.
The conventional power distribution grid is also centralized, allowing only unidirectional power flow, and with no way to monitor consumer usage. Peak load hours must be met by pressing additional, potentially polluting, plants into service to make up the deficit in power, once the utility is operating at its maximum load.
The smart grid uses digital technology to make power distribution and use reliable, transparent and efficient. This is in great measure due to the use of sensors. Sensors are incorporated at multiple places along the grid, and help to monitor usage as well as manage the power demand. They can tell how the grid devices are functioning, monitor the temperature, detect outages, and identify low power quality. This provides up-to-date information to the control center enabling just-in-time maintenance of the grid rather than regular (and often unnecessary) grid inspections.
Sensors also make smart meters possible, to allow monitoring of remote and local consumption, and allow meters to be switched off. This could result in significant cost savings as well as prevention of power theft from utilities.
Most countries are promoting the development of smart grids due to the high potential to cut down energy wastage. However, the extent of energy savings is still under investigation.
Many countries have at least a few smart buildings designed with technology to improve energy efficiency and better comfort for its users. This includes integrated information and communication technologies as well as building materials. Heating, ventilation and air conditioning systems (HVAC), lighting automated switching off/on of devices when not in use, smart metering, integration of standard household appliances and automated security or access systems are part of this plan.
These systems make use of temperature sensors, heat and light level detectors, movement sensors, gas detectors, air quality sensors and glass break sensors among others. It is estimated that such technology can save up to 30% energy costs for a building.
Intelligent Transport Systems
Digital and ICT technology can be incorporated into transportation systems to save on energy, time, money and above all, on human life and the environmental cost. These involve both intelligent vehicles and intelligent infrastructure.
Infrastructure sensors include those in pavements to monitor road traffic and provide data for automated traffic light controls.
Numerous areas are addressed by intelligent transportation, including emergency and routine management of arterial roads and freeways, crash prevention and safety measures during crashes, commercial vehicle operation surveillance and management, freight tracking and road weather information.
Intelligent vehicles can help avoid crashes by detecting obstacles, navigation guidance, and collision notifications.
The use of intelligent transportation systems allows improves costs and efficiency, with lower transit time, more flexible use of available facilities, and increased use of public transport. The possibility of increasing traffic volumes as a result must be investigated, of course.
Industrial Process Control
Industry accounts for almost a quarter of total greenhouse emissions and half of all power usage across the world. Sensor networks allow industrial processes to share their data and thus be more responsive to each other, while monitoring the health and functioning of the equipment and allowing better control of operations and resources. The overall outcome is higher efficiency, better productivity, consistent quality, reduced material wastage, and less energy use with reduced emissions.
Sensors in Power Generation
Conventional power plants also use sensors to reduce emissions of mercury, sulfur oxides, nitrogen and carbon dioxide, for instance. Sensors help improve the efficiency of the turbines, make the plant safer, reduce transmission losses, and reduce the environmental impact.
Some of the sensors used in these fields include:
- Pressure sensors
- Temperature sensors
- Flow sensors
- Level sensors
- Accelerometers and gyroscopes
- Noise sensors
- Magnetic sensors
- Gas sensors
Thus sensors find application in a wide array of areas which have a powerful impact on the environment. More study is required to quantify the savings in resource utilization, and to measure any rebound effects. Demand-side management is also crucial to prevent wastage from occurring parallel to the increased efficiency of supply and use. The expense of such technologies as well as of research to move them beyond the experimental stage is a potential challenge in this field.
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