BASIC KNOWLEDGE - SMART GRIDS The smart grid – what it is, and why we need it
As the demand for energy steadily increases, it can no longer be met by building more fossil fuel power stations, because of their pollution and contribution to global warming.Therefore, renewable energy is used instead – but it is a distributed, unpredictable resource that must be managed within a smart grid infrastructure.
For decades, our electricity needs have been adequately met by a traditional National Grid model which is conceptually quite simple. A small number of large-scale fossil fuel - or sometimes nuclear – power stations deliver power over long distances to where it’s needed; homes, commercial premises, factories and many other environments.
However, the energy market is a highly dynamic place, with many powerful factors of change. Some of these are leading to the demise of traditional grids, while others are facilitating the smart grids that are replacing them. If we look at both sets of factors, we will see why smart grids are essential, as well as how they can improve our access to and use of electrical energy.
Limitations of the traditional grid
Fossil fuel power stations have served us well for so many years because they are predictable and reliable. Operators can bring them online whenever they’re needed – unlike renewable energy generators, whose performance depends on prevailing weather conditions. However, these stations are highly polluting, and make significant contributors to global warming. Accordingly, many European countries have made commitments and set deadlines for phasing out fossil fuels.
Meanwhile, demand for electricity is steadily growing, as we live more of our personal and working lives online, and increase our uptake of electric vehicles. So, without making technological advances, we would have been left with a diminishing pool of fossil power stations endeavouring to support a relentlessly increasing electric load.
This stress would have led to an increasing incidence of power anomalies and blackouts on aging networks, with limited ability to detect faults and respond to them in real time.
Fortunately, new technologies have been becoming available, and are being deployed, to address these issues. These technologies, and especially the way in which they work with one another, can be grouped under the umbrella term ‘Smart Grid’.
Smart Grid technologies and interactions
The fundamental technologies driving the Smart Grid relate firstly to renewable energy, and secondly to IoT-type data-gathering, communication, analytics, and control. And renewable energy sources are mainly either wind turbines or photovoltaic (PV) solar panels.
Renewable energy has become effective in addressing the shortfall created by dwindling numbers of fossil fuel power stations and rising demand. The UK, for example, has been recorded as running for up to 18 days without using fossil-fuelled power. It also set a new solar power record on 20 April 2020 after solar farms generated more than 9.6GW of electricity for the first time.
While creating these milestones, renewable energy has the attractions of cleanliness and increasingly lower cost. Nevertheless, it is also unpredictably weather-dependent and widely dispersed rather than centralised. An area of a country may, for example, include a large-scale wind farm, but it could also have a large number of solar power generators. Some of these could be located on the sites of major energy users – so the users can feed into the grid during times of maximum demand, as well as drawing from it.
For this newer grid model, with its numbers of distributed energy sources, to function reliably and efficiently, it must be subjected to monitoring and control. In fact, it can be considered as a typical IoT application. Data can be collected in real time from line sensors, users, and generators, and communicated to a centralised control point that can perform analysis and control functions. This allows balancing of power loads, troubleshooting of outages, and management of distribution.
It also facilitates peak shaving, where grid operators can call upon energy supplies from users’ on- site renewable energy systems, or even batteries, to supplement their own capacity during times of high demand.
The grid develops self-healing properties, as control systems can detect simple problems and effect repairs without intervention. More serious infrastructure damage can be reported back to technicians in the control centre, allowing for a timely repair response. To further improve reliability and uptime, the grid can become adaptive, with power being rerouted to go around any problem areas. This limits the area impacted by power outages, and can work down to residential levels.
Users benefit too
While IoT-type intelligence will allow operators to visualise and manage their smart grids reliably and efficiently, it will also give energy users greater control. Smart metering allows even domestic consumers to see how much energy they are using, when they are using it, and its cost. Combined with real time pricing information, this will enable users to save money by using less power when electricity is most expensive.
The development of renewable energy resources is letting us fill the energy gap created by the dwindling number of fossil fuel power stations and rising demand. However, an infrastructure comprising a mix of renewable and possibly fossil fuel energy generators is complex, decentralised, and volatile, with multi-way power flows. Nevertheless, by integrating these resources into a smart grid, with IoT-type data collection, analysis, and control, they can become a utility that is cost-effective, safe, reliable, and flexible.