More than 6.5 billion people are expected to live in cities by 2050, according to UN estimates. That figure represents more than double the number of people currently living in such settlements. In order to withstand the pressure on infrastructure that this process of urbanization will bring, smart cities — referring to a concept by which cities’ traditionally offline systems such as water supply networks are brought online and connected to sophisticated analysis and control systems — are expected to grow commensurate with this process of worldwide urbanization.
Alongside provisioning special, low-powered telecommunications networks to support their connectivity, sensor technology is the key means for driving the growth of these projects, which are expected to rise fourfold in number by 2025.
The following are just some of the ways in which the latest breed of low-power sensors, specifically designed for monitoring city infrastructure, are helping to make the smart city dream a reality.
Installing a network of smart, Internet of Tthings (IoT)-enabled sensors can greatly improve the efficiency of any water distribution network. A key benefit of smart water networks is reducing non-revenue water, or supply water physically lost as it passes through the system due to leakages. Advanced sensing technologies, such as analytical techniques that measure water usage within a closed geographic area to assess loss, can provide utilities with real-time visibility on any leaks occurring. Advanced data analytics can add further insights by parsing the raw information from the sensors. According to a World Bank study, 32 billion cubic meters of water are lost annually due to such issues which, among other reasons, can often be attributed to poor or aging infrastructure and theft.
Like water, wastewater management can also be improved by using smart networks to connect infrastructure with control and monitoring systems, such as SCADA (Supervisory Control and Data Acquisition) platforms. Combined sewer overflow and sanitary sewer overflow events occur whenever sewer systems are filled past capacity and are forced to spill contaminated contents from designated overflow sites. Such events can have devastating implications for nearby residents and for the local ecosystem. When a sewer gate malfunctioned in King County, Wash., in February, 11 homes were swamped and 24 residents displaced.
The more real-time monitoring capabilities a utility has at its disposal (such as data from sensors to measure water quality, pressure and velocity) the quicker it can react to changing conditions to initiate remedial mechanisms such as manipulating underground gates and valves or activating ancillary treatment sites. Fewer overflows also extends the lifetime of equipment throughout wastewater networks.
Although from a consumer’s perspective it may seem hard to distinguish between the electricity supplied from one outlet to the next, this is not the case for industrial users for whom the consistency of voltage, frequency and waveform can have important ramifications for manufacturing processes and machine life expectancy.
Variations in power quality can result from voltage sags, spikes and swells. Even interruptions lasting only a few milliseconds can damage sensitive equipment. Continuous power-quality monitoring uses advanced sensing technology to analyze and interpret raw measurement data to improve systemwide power-quality delivery. This ensures that urban infrastructure systems requiring a consistent supply of high-voltage power, such as an electrified light rail, suffer less damage (such as from overheating) and component failures during their useful lifespan.
In city environments, every square meter costs. In an effort to support the dietary needs of the often colossal populations that inhabit their limited spaces, urban farmers use unconventional infrastructure such as skyscrapers and rooftops to harvest crops in and atop vertical farms. To effectively grow within such structures — which can be significantly less accessible than the conventional rural landscapes where most traditional farms exist — such farmers need real-time access to vital agricultural parameters such as evapotranspiration rates, soil moisture saturation and groundwater conditions. Smart, IoT-powered sensors allow these agricultural pioneers 24/7 access to this vital information no matter where in the world (or city) they are located. Chicago is quickly emerging as America’s urban agriculture capital with 820 urban farms now in operation.
Measuring air quality and weather conditions is increasingly important for those involved in the construction of new infrastructure. Whether building residential units, roads, bridges or any other piece of infrastructure, activities such as land clearing, running diesel engines, demolitions and burning can all adversely impact air quality, placing the health of the general population (particularly those with respiratory diseases) at risk.
Assessing atmospheric conditions, such as wind speed and direction, is also important to predict the risk of such pollution spreading to adjoining territories. Research has demonstrated that asthmatics are 40 percent more likely to suffer acute asthma attacks on high pollution days than on days with good air quality. Whether mandated to comply with legislation, such as the EPA Clean Air Act, or proactively initiated by companies seeking to minimize their environmental footprint, measuring gaseous air pollutants such as nitrogen dioxide, sulfur dioxide, carbon monoxide, ozone and particulate matter helps reduce pollution for the benefit of all a city’s inhabitants.
Smart sensors and special IoT communication networks are the two key components of any smart city project. Initiatives to implement the technologies mentioned here, such as the London Air Quality Network (which may involve a significant open-source component) and San Francisco’s ongoing efforts to develop a smart sewer network, show that IoT-supported sensor technology can have a far-reaching impact on the lives of urban citizens around the world.
Sivan Cohen, P.E., is the general manager of Ayyeka Inc.