Smart pavement graphic

Powering a Smart City

Resilience in the grid is crucial, but will smart developments be met by advances in renewable energy?

“We believe the biggest challenge facing cities of the future is two-fold: power reliability and power sustainability,” says David Chiesa, senior director of business development at the S&C Electric Company. “Power outages are incredibly disruptive for cities and their citizens; in fact, outages cost world economies hundreds of billions of dollars per year. Additionally, during major weather events like hurricanes, snow storms, heat waves and earthquakes cities rely on their electrical infrastructure to coordinate first-responders and provide essential services to citizens.

”It’s hardly surprising that ‘resilience’ has become the buzz word for companies like S&C when they talk about power and smart cities. From an infrastructure point of view, Hurricane Sandy in New York and Katrina in New Orleans caused unprecedented flooding and power cuts. But with such extreme weather events expected to increase as climate change develops, important questions still remain: what does being ‘smart’ or ‘resilient’ really mean, and is the push for more technology-driven, power-hungry cities just exacerbating the problem?

Three-pronged approach

For S&C, being resilient means keeping power grids in cities robust. Founded over a century ago in Chicago, the company built its reputation on providing reliable power distribution systems, and has recently turned its attention to high-tech solutions. “At its core our solutions prevent and reduce the frequency and duration of power outages,” says Chiesa, “ensuring that cities have a resilient grid.”

When talking about smart cities, he sees this as a three-pronged approach, with the first technology being what he calls ‘self-healing grids’. “[The] technology rapidly identifies problems on the grid, isolates them, and restores power to as many customers as possible. If you ever see your lights blink in a storm but stay on, this is self-healing technology in action,” he says. A series of smart sensors and switches are installed around a city’s power grid that, on detecting a fault or outage, automatically reroute power in different ways around the grid - a similar principle to how the Internet reroutes packets of data.

As well as making larger grids more robust, S&C’s approach encourages the use of ‘microgrids’, where parts of the grid separate, or ‘island’ away from the larger grid, and use local generation to ensure all or part of the microgrid can operate as normal until power is restored. “This is particularly useful to keep mission-critical facilities like hospitals or emergency response centres operational when the rest of the grid goes down.”

S&C recently installed what they claim is the US’s “most advanced microgrid system” in the city of Lancaster in Texas, which had long suffered from regular power outages. Fully autonomous, the microgrid allows different areas of the city to temporarily remove themselves from the grid if it fails, and to switch to using power from one of nine separate, local energy sources until the problem can be fixed.

The final part of their approach is energy storage - in essence, industrial-scale back-up batteries. “Energy storage has a number of versatile applications, including providing power in the event of an outage and helping the integration of renewable energy, like wind and rooftop solar, into the grid,” Chiesa says. “S&C has used energy storage to provide entire cities with power during outages and has helped communities better use their rooftop solar investments.”

A flood of sensors

Switzerland-based company Living PlanIT has a similar approach to the smart cities philosophy, also focusing on how networks can become more autonomous and resilient. In fact, its vision seems even grander. “I established the company in 2006,” founder Steve Lewis says, “with the view that the future of cities would require enabling technology that could help stakeholders consider the use of land in the context of economic, social and environmental imperatives to provide a common way to understand the physical and social world around us, make intelligent decisions to improve outcomes, and ultimately contribute to improvements in both human and environmental quality of life.”

Hyperbole aside, what this meant in real terms for Living PlanIT was designing and building the “PlanIT Urban Operating System” (UOS) - a software platform that allows a variety of systems and sensors to talk to each other effectively. It is, in theory, an intelligent operating system for cities.

“To understand the world around us we must be able to sense it,” explains Lewis. “We do this using: digital sensors, some very simple like temperature sensors and others significantly more complex such as lidar sensing to explore the ground; biological sensors, which combine digital technology with biological sources that can identify molecules and more complex bodies such as pathogens; and human communication from social media and other sources.”

This approach is very much the basis of the ‘smart city’ philosophy, saturating the urban environment with sensors while simultaneously monitoring the population in order to mine a city of all its available data.

“[When] combined, this information enables the UOS to determine change around us, through sophisticated real-time machine learning and artificial intelligence. A simple example of this is considering temperature, humidity, human movement, weather patterns and building materials to determine the optimum utilisation of heating, cooling and the flow of air to reduce the use of energy and emissions.”

This approach to smart-city infrastructure management is not without its critics and controversies, especially surrounding the collection, ownership, and use of data produced by human populations. But there’s a more specific elephant in the room when talking about energy management - the increase in power consumption and the additional carbon footprint created by the computers doing all that data mining.

A 2012 Greenpeace report highlighted the environmental cost of the kind of data centres that are associated with smart-city development, claiming that cloud computing currently consumes more electricity than India, with this projected to triple by 2020. As researcher and journalist Ingrid Burrington recently discovered, comprehending how much energy distributed computing uses is incredibly complicated.

“The impact of data centres - really, of computation in general - isn’t something that really galvanises the public, partly because that impact typically happens at a remove from everyday life,” she writes in the Atlantic. “The average amount of power to charge a phone or a laptop is negligible, but the amount of power required to stream a video or use an app on either device invokes services from data centres distributed across the globe, each of which uses energy to perform various processes that travel through the network to the device. One study estimated that a smartphone streaming an hour of video on a weekly basis uses more power annually than a new refrigerator.”

Start flooding the urban environment with similarly Internet-enabled sensors and smart switches, not to mention the interactive public touch screens and Wi-Fi hotspots that are associated with a city becoming smart, and it’s not hard to see how there could be a huge explosion in urban power consumption.

Perhaps unsurprisingly, both S&C and Living PlanIT are keen to downplay these concerns, claiming that their technologies will allow the energy cost to be offset. “S&C’s solutions focus on the electrical infrastructure of a city and making that infrastructure more reliable and sustainable for citizens and businesses,” says Chiesa. “One way we are helping is by enabling cities to diversify the sources of generation they use for power. By increasing a city’s ability to use renewable energy, and to use that renewable energy locally, we are [enabling it to become] less reliant on sources of generation that produce waste. The concern around data-centre energy use comes from the fact that the sources used to provide that high energy demand are typically carbon-heavy, but by enabling cities to use more renewable energy, we can reduce the overall carbon footprint of an entire city.”

For Lewis, it’s all about the efficiency data can provide. “Ultimately the urban environment is horribly inefficient - in its design, delivery and operations. Enabling technology can and will eradicate this waste, fund the infrastructure needed to address issues of economics and the environment while significantly improving social outcomes.”

Moving away from the publicity and marketing hype that surrounds networking technology, perhaps the answer to offsetting the environmental costs of smart cities is for them to start producing their own electricity. “In my opinion it is important that energy solutions for cities are developed in a systems approach, combining approaches to reduce energy consumption, both by technology and by social innovations, with solutions for renewable energy production,” says Sten de Wit of Dutch company SolaRoad. “Proper embedding and integration of these solutions into the built environment will be a key factor for acceptance and large scale implementation.”

Their idea seems both simple and fantastic - build roads out of solar panels, so cities can maximise the renewable energy they generate. “When people think about solar energy in the Netherlands, they mainly think about solar panels on rooftops. Fortunately we see the amount of solar panels on rooftops growing rapidly. However, if we look at the ambitions and goals that we have set for renewable energy generation and reduction of CO2 emissions, then much more is needed,” says de Wit. In a densely populated area like the Netherlands, and in many urban areas around the world, he adds that this area is ideally found close to where the energy consumption is, and integrated in the built environment.

Highway to energy heaven

Roads, in addition to rooftops, are an interesting option in integration. “In the Netherlands alone we have 140,000km of roads - those roads catch a lot of sun, more than all the rooftops together,” he says.

“With SolaRoad on a third of our road network, we could power eight million electric cars; that’s equal to the total amount of cars we have now. And this green energy production could be achieved without claiming any extra space, without disturbing the environment or nature. Simply in the roads that we build and use anyway.”

SolaRoad’s collecting panels come as prefabricated slabs. Each one consists of concrete modules of 2.5m x 3.5m with a translucent top layer of tempered glass, which is about a centimetre thick. Underneath the glass are crystalline silicon solar cells. Following the initial year-long trial of a 70m stretch of bike track in the city of Krommenie - where 9,800kWh of energy was generated: enough to provide three households with electricity - SolaRoad is refining the technology to work on a larger scale, as well starting work on five more trial installations; three in the Netherlands and two outside.

Embedding energy-generating technology in the ground is also the concept behind Pavegen, a company whose technology harvests the kinetic energy of footsteps on their specially designed floor tiles. “Every time someone steps on the tiles, the surface compresses,” explains Pavegen CEO and founder Laurence Kemball-Cook. “This compression triggers a flywheel, which, through magnets and induction, generates electricity. This electricity is then either stored in batteries or used to power applications such as lighting and signage.”

Seemingly fitting perfectly with the smart-city philosophy of harvesting personal data - in fact it does this too, it’s able to collect and wirelessly transmit footfall statistics - Pavegen certainly seems like a promising fit for urban environments. The technology has been installed in a number of locations globally, from Heathrow Airport to a football field in Nigeria, and seems - presuming it is cost effective - a logical ‘step’ for cities, or at least areas where citizens are constantly on the move.

“The technology definitely has the potential to contribute towards energy usage on a large scale,” says Kemball-Cook. “For example, King’s Cross Station receives over half a million visitors daily. If our tiles paved the flooring throughout the station, we could harness energy from each footstep and power lighting, interactive displays and phone-charging stations.”

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