Increasingly, climate change and smart energy consumption are at the forefront of governmental policy. In April 2021, the UK government set into law the world’s most ambitious climate change target to cut emissions by 78% by 2035 compared to 1990 levels. Significant change across many sectors is necessary to achieve these goals, and smart grids and smart cities are in the spotlight as a solution to both environmental goals and increasing urbanisation.
What are smart grids?
“The grid” refers to the electric grid that delivers electricity from power generators to consumers, consisting of generators, transformers, transmission lines, and more. There are many different definitions of the term smart grid, however these can be summed up to generally define an electrical grid using digital technology for communications, monitoring (e.g. sensing), computation, and control.
How do smart grids help?
By using advanced metering infrastructure, which are systems that measure, collect, and analyse energy usage, power generators and consumers are linked through bidirectional exchange of information. This allows for real time monitoring of electricity supply, enabling power generators and the grid to control and anticipate energy usage.
From a consumer’s point of view, they can see their energy consumption and real time pricing of energy, so that they can make decisions to limit their energy consumption and to use devices at less costly off-peak times.
Importantly, smart grids facilitate the implementation of sustainable energy sources. Renewable resources, such as wind and solar, are variable due to weather dependency, and therefore cannot reliably power the grid at all times. However, by storing energy generated using renewable resources, and using a smart grid system to monitor and anticipate electricity usage on the grid, these resources can be used side by side with more reliable energy generation methods.
How do smart grids fit into smart cities?
Much like smart grids, smart cities are made "smart" by the implementation of digital technology. Smart grids fit into these cities by allowing for the implementation of exciting technology within smart cities, like those being used in relation to electric vehicles (EVs).
Vehicle to grid charging of EVs – Renewable energy relies on battery technology as a means of energy storage to power a smart grid reliably. EVs have batteries with large capacities, which can be used as backup energy storage for the grid. During peak times, when usage is high, electricity can be discharged from the vehicle back to the grid to stabilise demand as required.
On the move charging of EVs – Limitations in how far EVs can drive is considered one of the greatest hurdles for their full-scale implementation. However, with increased developments in smart grid technology, on-the-move charging can become a reality.
On-the-move charging, or "dynamic charging" as it is also known, is when an EV is continuously charged while it is being driven. This can be done using electric transmitter coils beneath the road surface which charge the car battery wirelessly through electromagnetic induction. Another method uses overhead electrified wires, which are connected to the EV to charge the battery. Overhead electrified wires are already used on vehicles such as trams, and this technology is being trialled for use with EVs on highways.
What’s going on at the present?
Before we can achieve the modern technology previously mentioned, it is vital that the grid is upgraded to reach isolated places and provide reliable power. In a recent exciting development, Hitachi has been contracted to connect the Shetland Islands to the UK transmission system for the first time. The multi terminal high-voltage direct current (HVDC) system that Hitachi will deliver will connect what will be the UKs largest onshore wind farm to the UK system. The HVDC system will also allow for power transfer in both directions based on supply and demand.
Conclusion
With advancements in sustainability, and increased consumer control touted amongst the benefits of smart grids, it seems that smart technology is here to stay. Therefore, looking forward, I believe that we have a lot to be excited about with the growing implementation of digital technology within our electricity grid, and in the cities of our future.
