# Internet of Things (IoT) and the Energy Sector
## 3 Enabling Technologies
### Sensor Devices  
Sensors are the key drivers of IoT [42]. They are employed to collect and transmit data in real-time. The use of sensors enhances effectiveness, functionality, and plays a critical role in success of IoT [43]. Different types of sensors exist that are developed for various application purposes. The examples of these applications include agriculture industry, environmental monitoring, healthcare systems and services, and public safety [44]. In practice, in the energy sector including energy production, transmission and distribution, and production, many these sensors are used. In the energy sector, sensors are used to create savings in both cost and energy. Sensors enable smart energy management system and provide real-time energy optimization and facilitate new approaches for energy load management. The research and future trends of the sensor devices are also aims at development of sensor applications to improve load shaping and consumers' awareness as well as development of specific facilities to enhance production of renewable energies [45]. In nutshell, the use of sensor devices within IoT, in the energy sector largely improves diagnostics, decision-making, analytics, optimization processes and integrated performance metrics. Due to the large number of sensors used in the energy sector, in the following we explain few examples of commonly applied sensor devices in energy production and consumption. _Temperature sensors_ are used to detect the fluctuations in heating and cooling a system [46]. Temperature is an important and common environmental parameter. In the energy sector, the basic principle of power generation is the process of changing mechanical energy into electrical energy, whereas mechanical energy is achieved from heat energy, e.g., thermal power plants, wind, water flow, and solar power plants. These energy conversions are obtained using thermal, i.e., temperature. In the energy consumption side, the temperature sensors are used to maximize the performance of a system when temperature changes during normal operations. For example, in residential areas the best time for turning on or off the ventilation and cooling systems is recognized by temperature sensors; thus, the energy can be managed correctly in order to save energy [42]. _Humidity sensors_ are used to distinguish the amount moisture and air's humidity. The ratio of moisture in the air to the highest amount of moisture at a particular air temperature is called relative humidity [47]. The applications of humidity sensors in the energy sector are wide. For example, they are generally used in wind energy production. The use of humidity sensors on wind turbines are even vital, if the turbines are located offshore (due to the high level of moisture in the air). Humidity sensors can be placed in the nacelle and in the bottom of wind turbines and offer continuous moisture monitoring. This enables the operators to take actions to changes or deviations in the turbine operation conditions, leading to more consistent operations, optimized performance, and lower costs of energy. _Light sensors_ are used to measure luminance (ambient light level) or the brightness of a light. In energy consumption, light sensors have several uses in industrial and everyday consumer applications. As a main source of energy consumption in buildings relates to lighting, which, respectively, account for nearly 15% of total electricity usage [48]. On global scale, approximately 20% of electricity is consumed for lighting [49]. Therefore, light sensors can be utilized to automatically control lighting levels indoors and outdoors by turning on-and-off or dimming the light levels, suchthat the electric light levels automatically can be adjusted in response to changes in ambient light. In this fashion, the energy required for the lighting for the indoor environments can be reduced [19]. _Passive Infrared (PIR) sensors_, also known as motion sensors, are used for measuring the infrared light radiation emitted from objects in their surroundings.