Where Sensors Will Rule the Smart Grid
Published: August 20, 2014 Category: Smart Technology

Today's electric grid infrastructure faces a number of challenges: a centralized communication system that lacks interoperability, inaccurate management systems, and inefficient operations and maintenance processes, all of which are increasingly costly and hamper efforts to maintain grid reliability. This is even before introducing more renewable energy, energy storage, and electric vehicles into the equation.

“Smart grids” promise to solve many of these problems by enabling broad knowledge and control of operations at all levels, from generation to transmission & distribution to end-use, to help better understand and take action regarding areas that are key to maintaining grid health and stability. These will depend upon real-time collection and communication of a wide range of data throughout the grid. Examples include measuring voltage and inductance levels in the T&D network, time synchronization and equipment temperatures at substations, and smart meters and energy conservation in homes and businesses.

All these multiple sensing, monitoring, and control functions will translate into enormous opportunities for various types of sensors. Below are some of the specific market opportunities NanoMarkets anticipates — some of which need more time to be available or become reliable.

Note that the proliferation of sensors and sensor-enabled capabilities into smart grids will lead to increased consolidation and M&A activity in the sectors around them: e.g., smart metering, outage management systems, SCADA, data computing & analytics, and feeder automation. This is especially likely as broad sensor manufacturers show keen interest in developing sensing solutions for smart grid applications. Moreover, advanced sensor technologies also will expand the addressable market base for smart grid sensors, with suppliers seeking avenues to cross-sell their products into other industries such as water, gas, transportation, and telecom.

Sensors in grid management applications

– Advanced/next-generation SCADA: This is a growing need in both the generation and distribution sectors. On the generation side, sensors enable higher efficiency baseload operation of thermal power plants through improved process control, heat rate improvements, and turbine and generator efficiency. Meanwhile, complexity in distribution, especially in dense urban areas, is driving the need for next-generation SCADA systems that can monitor the health and safety of transmission lines and circuit breakers. These include various combinations of sensors to measure voltage, current, capacitance, chemical, gas, humidity, moisture, temperature, time synchronization, and intelligent electronic devices (IED). Wireless sensor networks (WSN) will be the future technology of evolved SCADA networks, possibly replacing the remote terminal units (RTU) in conventional systems.

– Outage management: Integrating smart sensors with current fault monitoring circuits provides more reliable and accurate monitoring of, and response to, outages along the grid. Sensors here can provide real-time critical system information, often inductively powered using batteries or energy harvesting systems.

Advanced metering infrastructure (AMI) has become an essential part of smart grids for monitoring metering activities and controlling excessive power outage problems. Sensors connected to AMI also can detect air quality, and automatically send warnings to nearby cellular devices. We see AMI sensors in wireless sensing deployments gaining a lot of interest in smart grid activities, particularly “Smart City” projects in both developed and developing countries. Examples include “intelligent” streetlights with environmental sensors to monitor air and traffic flow. We expect to see good progress in technology standardization, plug-and-play interoperable devices, and M2M communication protocols.

– Synchrophasors: Measured by phasor measurement units (PMU), these give a better indication of grid stresses so grid operators can prescribe corrective actions, or even initiate automated actions. Cost has been a limiting factor in PMU adoption, but we expect costs to come down as demand for the devices and their functionality increases. As synchrophasors are incorporated on a large scale, wide area management systems (WAMs) in transmission infrastructure represent immediate and near-term opportunities. Specific sensors here address time synchronization, voltage, data analytics, and decision making.

– Power quality: Sensors allow distribution network operators and large users of electrical power to record vital information regarding power quality, more efficiently and less costly than conventional methods such as power quality analyzers or temporary monitoring. Power quality management (PQM) sensors in a smart grid need to sense voltage fluctuations, unbalanced phase voltages, and harmonic disturbances in the power grid.

– Distribution automation: As traditional electricity distribution migrates to automated systems, there is an immediate need for sensors used in areas such as substation automation, feeder automation, and load balancing. NanoMarkets expects that smart sensors will be deployed as an indispensable part of distribution automation systems. We especially see significant opportunities for smart grid sensors in feeder lines and transformer monitoring.

– Asset monitoring and control: Sensors play a key role in identifying and locating faults on a power line, measuring and recording vital parameters of the power line such as current and conductor temperature. They also can be configured to provide periodic measurements to facilitate improved situational awareness and operations. Smart monitoring features also can be applied to circuit breakers, turning them into basic alarms for SCADA by adding external sensors to monitor key parameters (pressure, leakage current, temperature, and SF6 gas) of the switchgear.

Increased complexity in supply chains and increased deployment of electrical equipment require effective asset management programs. Real-time monitoring of critical equipment is gaining importance over cumbersome documentation and physical verification. Sensor types include time synchronization, voltage, current, weather, temperature, and humidity.

Sensors in demand-side applications

– Demand response: Present grid systems depend on manual load shedding to maintain grid reliability during emergency situations. Opportunities are huge for sensors in demand response. These involve home area networks to monitor various equipment, including smart meters and new “smart appliances” that are arriving on the market, embedded with wireless technology to extend device control even deeper into the home. Building codes and standards also are evolving to cover demand response.

– Building energy efficiency: With the evolution of energy conservation and building codes, there is a huge opportunity for sensors to monitor and manage energy efficiency in commercial/industrial buildings. These sensors will be networked, operating in the “Internet of Things” and accessible via the web and mobile devices for optimum performance. Sensors can be used to augment facilities automation and energy efficiency programs, e.g. tied to changing from CFL to LED lighting (timers, dimmers and photo sensors), streamlining operation of motors and pumps (speed control, temperature, Hall-effect sensors, etc.), and energy conservation programs (infrared and occupancy sensors).

– Smart meters: In consumer homes, smart meter technology is advancing rapidly with increased complexity, with a heavy reliance on sensor functionalities to make them smarter, more robust, and less costly. These include several types of sensors to enable new functions such as tamper detection, switchable operating modes, and PCB temperature sensing. NanoMarkets expects to see exponential growth in consumer demand for remote energy control in the form of sensing systems.

Emerging applications for sensors in smart grids

– Renewable energy integration: Installed power capacity of solar and wind power farms is more than 300 GW as of 2014, with tens of thousands of worldwide power generating sites, each of which could be upgraded (or designed from the outset) to incorporate dozens of smart sensors. Energy generation from varied resources, especially renewable energy, will be managed by advanced sensors for data monitoring and algorithms. Examples include LIDAR, SODAR, sky cameras, and imagers to help forecast power output; as well as sensors to monitor voltage, current, phasor measurement, and capacitance and inductance.

– Electric vehicles: Similar to the case of renewable energy integration, the present grid has to manage the increasing popularity of electric/hybrid vehicles (EV) and their varying charging demands. Vehicle-to-grid (V2G) during peak load times require more grid-interactive vehicles, and the establishment of a charging grid infrastructure with appropriately defined standards. We see a growing demand for accurate measurements that can be only fulfilled by high-quality sensors to monitor various EV functions: battery, voltage & current, safety systems, automotive performance, and humidity/air quality/temperature.

– Microgrids: Microgrids require large numbers of sensors (more than 50,000 per grid in some big microgrids) for monitoring functions, sensing frequency and voltage disturbances and seamlessly connecting and disconnecting microgrids with the grids. Examples include controllers, frequency and voltage sensors, and communicable relay controls.

– Energy storage: Sensors for energy storage are in an early stage of deployment as energy storage systems are still too costly for wide deployment. Ultimately, energy storage systems will require a wide range of sensors for asset monitoring, current, temperature, discharge rate, load leveling and sensors for synchronized operation with the grid.

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