Technology | Analysis

On the grid: the smart tech driving green city evolution

The world needs a green city revolution, and smart grids may be the catalyst, as Giacomo Lee discovers.

Cities may account for less than 2% of the Earth’s surface, and yet, according to UN research, they collectively put out more than 60% of greenhouse gas emissions while consuming 78% of the planet’s energy.

It's clear that the world needs a green city revolution. This revolution will probably not be galvanised, coming through at the almost-imperceptible rate at which cities around the world are becoming smarter. Nor is a smart city necessarily a sustainable city.

late 2019 report by the Environmental Industries Commission (EIC) revealed that “only a small proportion of smart city activity was focused on environmental issues”, finding 20% from a sample of current smart initiatives to be environment-related.

What will quicken the pace of innovation, though, are smart grids and electric vehicles – two intertwined technologies that are becoming ubiquitous in cities around the world.

Smarter grid, greener city?

Smart grid technology help electricity grids to respond digitally to electricity demand patterns. These patterns can change rapidly among larger populations.

IT and communication modules, including control systems and automation, enable smart technologies to merge and smarten the grid. This, in turn, optimises power generation and distribution to serve more end users.

A lot of this technology is part of the internet of things. Its impact can already be felt in homes today: Advanced metering infrastructure, for example, allows customers to pay less for night-time and low-peak energy consumption.

Smart apps in the home make grids smarter, too, turning off devices when users aren’t present. Electric and digital devices, whether smart or not, can all be networked together in modern homes.

Combined with a power electronic interface, a microgrid is a completely self-sufficient network which, in an emergency, can operate independently of the central grid.

Another key part can be found outside the consumer end. Energy management systems monitor, control and optimise generation and transmission systems with computer-aided tools. Various subsystems help restore power after outages or, more usefully, mitigate the chances of outages within energy-guzzling cities.

Microgrids are even more useful in the front-line defence against power disruption. Combined with a power electronic interface, a microgrid is a completely self-sufficient network which, in an emergency, can operate independently of the central grid.

This island mode came in useful for one district in the Japanese city of Sendai, which managed to maintain working power during the 3/11 earthquake thanks to the presence of microgrids.

The EV conundrum

Charging points for electric vehicles (EVs) offer a visible infiltration of smart green power in the city. Plug-in hybrid electric vehicles rely on smart grid technologies to get their charge from power utilities, and also allow car owners to supply electricity back to the grid with the energy stored in their car batteries, or by reducing charging frequency.

This vehicle-to-grid (V2G) technology, as it’s called, is good for the green city, helping to store the amount of energy generated from renewable resources so that it can be sent back to the grid as required.

EV charging infrastructure is growing worldwide, bringing with it movement in the smart grid space. According to International Energy Agency, the number of publicly accessible chargers increased by 60% in 2019 compared to 2018. The growth was, as GlobalData points out, mainly driven by China due to its dense city areas with less opportunity for private home charging.

In response to this growth, two of China’s major power utilities are ramping up spending on EV infrastructure, with China Southern Power Grid planning to provide more than $3.6bn over the next four years into EV charging infrastructure. Its competitor, State Grid, plans to build around 78,000 new charging points, involving 53,000 EV charging sites in private residential buildings and 18,000 dedicated for public use.

In Amsterdam, for example, EV charging requirements could bring a five-fold increase to the load on the city's electricity network within peak hours.

Second behind China in the EV stakes is the US, which is offering incentives in more than half of its states. India, Indonesia and Brazil, meanwhile, are forecasted to see a steep rise in public EV charging.

It's worth bearing in mind, though, that V2G is a clean solution and a solution to the energy conundrum that EVs bring to cities. An increase in the numbers of EVs being used in a city has implications for the city's electricity grid.

In Amsterdam, for example, EV charging requirements could bring a five-fold increase to the load on the city's electricity network within peak hours.

In response, charging stations in Amsterdam generally provide less output in the evening when households need more electricity. They then ramp up their output at night when energy consumption is low. This is regulated by a smart charging network which can adjust its charging speeds to energy demand and the amount of energy available at any given time in the city, all thanks to smart grid capabilities.

That Amsterdam plans to ban all petrol and diesel vehicles from city streets by 2030 also offsets the EV conundrum, and would be a wise move to follow by any other metropolis wanting to become a green city whilst managing the changes in energy requirements created by the rise of EVs.

Will yours be a green city by 2030?

With cities consuming so much of the world’s energy, it is clear how important their use of smart technologies and energy efficient solutions is to global sustainability.

GlobalData’s thematic research on smart cities forecasts the smart city market to grow to $231bn by 2024. This market breaks down into five constituent parts, with the biggest growth coming from smart metering, inclusive of smart grids. The smart metering market is expected to grow at a compound annual growth rate of 2.3% between 2019 and 2024 to reach nearly $122bn.

GlobalData recommends overall global grid spending should “rise by around 50% over the next decade in order to attain long-term sustainability goals” and that, in addition, spending on digital grid infrastructure should also surge, especially with the ever-expanding prominence of environmental, social and corporate governance.

This will be the only way for cities to speed up becoming smarter and greener. The world may thank them for it.

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