The fact that approximately 74 per cent of Europe’s population are city-dwellers is a testament to how people have been drawn to cities throughout history.
Whether for a lack of job opportunities in rural areas or possibilities for a better lifestyle, unfortunately the unprecedented speed and scale of urbanization does put tremendous pressure on a city’s resources, often resulting in detrimental environmental impacts.
With urban growth showing no signs of slowing and the rise of smart cities, there is no question that current infrastructure will no longer be able to sustainably accommodate the demands of a 24/7 society, implying a need to not only revamp archaic energy network infrastructures, but also to break reliance on fossil fuels.
Urban settlements already consume over two-thirds of the world's energy, despite occupying only 3% of its landmass. And regardless of what climate change deniers would like to advocate, the fact of the matter is humankind has drastically altered the Earth's atmosphere through the indiscriminate burning of non-renewables, throwing our planet into a state of ecological overshoot.
Given that cities lie at the heart of many of today’s climate challenges, the onus is on them to reshape and improve current energy systems in order to make way for a more sustainable and energy-secure future.
By laying down the groundwork for smart and clean energy infrastructure of the future, cities can support the EU's objective to cut carbon dioxide emissions by at least 40 percent by 2030, compared to 1990 levels.
Reliable and resilient
As cities become smarter, energy and access to it will become an even more integral part of modern living. In other words, on top of addressing an unsustainable demand for energy, new energy systems must also be increasingly more reliable and resilient.
Despite their dependence on natural processes, the broad consensus among energy experts is that solar and wind remain the best candidates in terms of new major energy sources, and should form the backbone of future energy systems. In fact, solar panels have made such substantial leaps since their inception a few years ago that prices have dropped around two-thirds since 2011, making them great investments until the end of March 2019 when Feed-in Tariffs will end.
However, the transition to a solar-wind energy economy comes with its own set of challenges, including inherent inefficiencies in current energy storage capabilities. This is particularly apparent in the transport sector, which has the most trouble when anticipating its energy transition.
Given the intermittent nature of wind and solar energy, it is also necessary to question our current focus on traditional centralized power production and distribution, which if unchanged, will become harder to maintain. Evidently, integrating wind and solar into our energy system requires significant investment in research, let alone in equipment and deployment.
As wind and solar become mainstream technologies and see even more rapid adoption, one of the biggest hurdles cities will need to overcome is energy storage. This stems from the fact that the grid has very little storage capacity, meaning that output fluctuations from wind or solar energy increase the complexity of operating it.
According to the European Commission, ‘energy storage’ in this context can be defined as "the act of deferring an amount of the energy that was generated to the moment of use, either as a final energy or converted into another energy carrier", which simply means saving electricity for later use.
The dominant energy storage technology today is the lithium-ion battery, owing primarily to its high energy density and low self-discharge rate. These batteries are used typically for short-term storage, but can also be found in electric vehicles as well as on power grids. However, if energy storage were to scale up, it would become much easier to balance power fluctuations and mitigate peaks in grid demand.
Recently, redox flow batteries, or vanadium flow batteries, have emerged on the market as a solution for larger-scale, long-term energy storage. These batteries are expected to revolutionize the energy storage market not only because are they able to provide hundreds of megawatt hours at grid scale, but they can also last over 20 years without any loss in storage capacity. By managing demand and supply and smoothing out the power generated by intermittent renewable energy sources, these batteries help ensure that no energy is wasted.
One country resolutely pursuing grid-connected residential batteries, is Germany; as of August, total solar battery installations in Germany exceeded 100,000, a figure that is also expected to double by 2020.
Unfortunately, large-scale energy storage solutions, including redox flow batteries, are still in their infant stages, which means that these technologies are still very expensive and therefore unviable. However, that is not to say that energy storage will not see explosive growth in coming years.
As a matter of fact, it is anticipated that economies of scale and improvements in design will help drive down costs of energy storage systems by roughly 50 percent to 70 percent by 2025, doubling the industry’s valuation to approximately £2bn by 2030. This is welcome news as cheaper energy storage would also open up a number of other opportunities in our cities’ transition to a carbon-free future, the most important one perhaps being transportation.
In conjunction with energy storage solutions, another vital component of the future energy system is the smart grid. IoT-enabled smart grids are powered by demand-response systems. In addition to reducing peak load and the need for larger grid infrastructure, smart grids--in combination with smart meters--allow energy derived from solar and wind sources to be optimized.
In the same vein, another concept that has taken root and garnered a fair amount of support from eco-conscious homeowners is the microgrid, a localized power grid that can operate either in conjunction with the main electrical grid, or independently of it as an “island”.
The idea behind microgrids is to break the hegemony of a centralized energy system, and make distributed energy resources (DER) infrastructure more resilient and reliable. By working independently of the grid when needed, microgrids protect communities from outages during natural disasters. They also benefit areas that were previously unreachable by traditional energy delivery practices in addition to enabling local "energy communities" to sell any surplus energy that they produce back to the main grid.
Essentially, by making homeowners and businesses interactive collaborators with the grid, microgrids put the power back in the hands of “prosumers” in that they can both use as well as distribute and profit from the energy they generate amongst themselves.
The end goal is to democratize the energy sector and create resilient, interconnected neighbourhoods, or "smarthoods", where all the different components that make up an energy network are entirely self-sufficient.
Balancing smart and sustainable
At this critical crossroads in time, it is a near certainty that if cities do not act now to address climate change, we could find ourselves in a far more precarious position in the future.
As economies transition to smart cities, reliability and resilience are becoming increasingly prominent determinants of newer energy models. Microgrids can fulfill energy needs in a sustainable manner while energy storage solutions ensure reliable supply.
Of course, while cities can play the role of front-runners in the transition to a carbon-free world, it is ultimately up to national governments to enable the delivery of no-carbon initiatives and provide them the support necessary to efficiently use the available financial, natural, and human resources.
Governments able to streamline their core services using IoT and show that sustainability is at the top of their agenda will not only attract more people, but also businesses, gaining competitive advantage over other economies. Inaction, however, will result not only in further environmental degradation, but also reduced citizen welfare.
Looking ahead, cities of the future need to be more mindful of their impacts and anchor their priorities around sustainable development. They must tap into their knowledge capital, and use their forums for collaboration to galvanize the change needed to safeguard global health and prosperity.
Avi Sood is a Communications Assistant with GreenMatch. This article first appeared in our sister publication Renewable Energy World.