For more than a decade, human beings have been an urban species rather than a rural one: a majority of us live in urban areas, and some of us live in densely-packed cities, with thousands of people living, eating and working within a few kilometres of us at any given time. And the proportion of us who live this way looks set to grow; by 2040, it is estimated that more than two-thirds of us will be living in cities.
This has considerable implications in many areas of life, but among the most significant concerns how to provide all of these people with the energy they need, without compromising on emissions targets. This will require innovation, strategy and foresight, and the end goal isn’t entirely clear. But we can form at least a vague sense of what might be in store – and some of the possibilities are truly exciting.
Some of the most immediate and dramatic changes will take place on urban roads. The cost of a lithium-ion battery has been steadily declining for the last decade, which means that the electric car will soon become not only practical but desirable. Such vehicles are superior to their gas-guzzling equivalents in innumerable ways; they are vastly more efficient, contain fewer moving parts, and they generate less noise. The cost of Li-Ion still needs to decline a little further before the electric car becomes cheaper to operate than a traditional one, but the tipping point will be with us within a few years if trends continue. City centres can embrace this transition by adopting charging infrastructure pro-actively.
The way we generate energy is changing. Burning fossil fuels is on the way out (even if the exit is dragging out slowly) and renewables are coming in. But the way we consume energy might also change – we might come to regard it not as a product, but as a service. Businesses would compete to provide that service as efficiently as possible, by encouraging the consumer to reduce waste. This might in turn lead to a decentralisation of production, with apartment blocks being equipped with solar panels and wind turbines so that the energy can be consumed locally. A series of high-capacity batteries, perhaps built into the building’s basement, would act as a buffer, and ensure that the supply remained constant, and absorb short-term shocks. By connecting multiple buildings of this sort, we might end up with a resilient, economical model for inner-city energy production and consumption.
Another possibility stems from the world of Big Data. We now know more than ever before about the amount of energy we’re consuming and the manner in which we’re consuming it. This information allows us to predict spikes in demand, and make small adjustments at the home level to compensate for them. For example, putting the kettle on in your home might instruct the fridge or the air purifier to dial back slightly, thus ensuring a constant, predictable load on the grid. This, along with the introduction of a more efficient AC to DC converter at every stage of the supply line, might reduce consumption, and therefore emissions, and help solve the energy dilemma for urban planners.