09-01-2023 | By Robin Mitchell
Reports have recently revealed that wind energy accounted for more than 80% of the UK’s, breaking all renewable records. However, while many tout this as demonstrating the power of wind, it actually demonstrates the continuing challenges faced with renewables and how focus needs to be shifted towards energy storage. What exactly has been reported, what challenges do renewables face, and why is energy storage the single most important technology that needs development?
UK wind energy record broken
In a recent report from the National Grid, the total energy produced by wind in the UK jumped to approximately 20.91 GW on the 30th of December 2022. When combined with all other green technology and zero-carbon sources (including nuclear), the total amount of energy generated was able to meet 87.2% of all UK demand, leaving just 13% handled by gas and other non-renewable sources. In addition to this new record, wind power has also been stated to provide somewhere between 55% to 59% of power over the last few years.
Furthermore, there have been numerous occasions where wind power has generated so much energy that network operators have instructed wind turbine farms to stop energy production, demonstrating the sheer amount of energy that wind in the UK has to offer. However, the recent cold weather snap also brought about little wind, which saw the total energy production from wind drop to almost zero.
The result of this recent record-breaking energy generation has seen many convinced that wind is the renewable energy of the future for the UK, and the hoped reversal of the current on-shore wind farm ban will introduce a new era in renewable energy generation.
Why this story is nothing to celebrate
Despite the overwhelming response from climate enthusiasts, the recent wind energy generation pattern is anything but worth celebrating for one simple reason; consistency. Having wind turbines in the UK produce tens of gigawatts of energy is great, especially if it reduces our dependency on gas and other fossil fuels, but if that energy is sporadic and unreliable, then it is far from being an ideal long-term solution.
Energy demand is surprisingly predictable, with energy demand increasing during the day and decreasing during the night. Over a year, the energy demand tends to increase during the winter, when heating is required, and energy demand over the years steadily increases. Meeting these energy needs is very easy to do with fossil fuels such as coal and gas as these power sources can be cycled up and down as needed, and so long as there is a sufficient stockpile, this energy is entirely predictable.
Wind energy, however, is only available when the wind blows, and the recent report clearly demonstrates how this availability can change dramatically. The initial cold snap saw almost no wind production, and a sudden storm that brought strong winds allowed most of the UK’s energy to come from wind. Worse, there have been times when wind energy has been overproduced, meaning that large quantities of usable energy have gone to waste. This dramatic change from 0GW to 20GW is something that modern life cannot utilise effectively, meaning that no amount of wind turbines will remove our dependency on coal and gas.
Why energy storage is the single most important goal for energy providers
Fundamentally, the most crucial goal that energy network operators need to work towards is energy storage. The unreliability of wind, solar, and tidal energy sources make them unsuitable as a stable energy source at any one point in time, but being able to store their excess energy production and then release this energy when needed would not only make renewable sources viable but even preferable over traditional energy sources.
Of course, an energy storage solution would face numerous challenges, including the technology used, the amount of energy it can store, the amount of instantaneous power it can provide, and its cost. Some companies are exploring the use of Li-Ion batteries, but while these have proven to be successful in vehicles and phones, scaling them up to industrial-sized units introduces serious fire risks, high costs, and limited resource availability.
Gravity storage solutions are promising in that they are very cheap to manufacture, can be easily scaled, and are able to store energy in a safe form, but the large amount of space needed for such facilities makes them unsuitable. An alternative solution to gravity storage is pumped storage that pumps water to a higher reservoir during peak energy production and drains the reservoir when energy is needed. While these can be made to store massive amounts of energy, they often contribute to environmental damage by destroying habitats and increasing the risk of flooding.
Other researchers are turning to thermal masses for energy storage, whereby excess energy is used to compress gas or heat a large thermal mass. The decompression of a gas generates energy through motion, but the initial compression of the gas generates heat which can be stored for later use.
Regardless of the technology chosen, energy storage is vital for renewable energy sources as it allows energy to be stored during overproduction and released when needed. One million wind turbines could be built, and this would provide all the energy required by the UK on a windy day, but one million multiplied by zero is still zero, and thus the UK needs to shift its focus towards energy storage before building more wind turbines.