Keeping the lights on in an age of renewable energy
Accelerating the energy transition is an urgent necessity if we are to avoid climate catastrophe, but first we need to overcome the challenges that a dramatic increase in wind and solar energy brings.
‘Dunkelflaute’ – this word gives some people in the energy industry the shivers.
The German word can not be directly translated to English, but it’s a combination of the word ‘Dunkelheit’ (darkness) and ‘Windflaute’ (little to no wind). Caused by the North Atlantic Oscillation (NOA), Dunkelflaute fills industry experts with dread as it foresees our vulnerability in a world where we will be relying more and more on the sun and wind to generate our power.
DNV GL’s Energy Transition Outlook forecasts that electricity’s share of the total energy demand will more than double to 45% in 2050. This surge in global electricity production will be powered by renewable sources, accounting for an estimated 80% of global electricity production in 2050. As the costs for wind and solar continue to fall, those two energy sources are set to meet most of the electricity demand, with solar PV delivering 40% of electricity generation and wind energy 29%.
Wind and solar energy generation, by their nature, are at the mercy of uncontrollable – if predictable – weather patterns. So, imagine, for a moment, a time in the not-so-distant future when we are relying on these variable renewable sources to meet our electricity needs. What will happen when ‘Dunkelflaute’ strikes?
In many parts of the world, the highest risk period is winter. Conventional power stations can keep running during periods of darkness and no wind, but in the future, a Dunkelflaute during winter’s combination of low temperatures and shorter days means that there will be less renewable energy being generated, at a time when demand for energy is at its highest.
Worryingly, the volatile weather events we’ve seen in the past year alone, including the heat wave in Europe in the summer of 2018 and the extreme cold weather front that gripped North America in early 2019, not only highlight the changing nature of our climate and urgent need for us to move to renewable sources but also the increasingly challenging task of ensuring technology keeps pace with the demands of the energy transition. System operation – with the main task of keeping the balance between supply and demand under all circumstances – becomes extremely complex.
Preparing our networks for variable renewables
We urgently need to prepare for a rapid increase in variable renewables, not only because of the climate challenge, but also because of the increased dependency of society on electricity, caused in part by the increase in electric vehicles and the replacement of CO2 emitting conversion technologies (but that’s another blog).
A combination of solutions is needed, including improved prediction of renewable power generation levels, demand response to react to excess renewables and shift electricity usage during peak periods. Continued investment is needed in the interconnectors between physical transmission systems and also in the links between generation and load centres. One good example is the Nemo Project, which will see a transmission cable from Belgium to the UK grid built to deliver 1GW of power. Just one of many other plans for interconnecting systems, in Europe and elsewhere.
Underlying all these technology developments is the assumption that the installation of smart sensors, improved connectivity and the application of new technology will enable better use of the data they provide, to optimise performance, prolong lifetime and predict failures before they occur, thereby reducing costs. Applying digital technology to network operation will also enable continued high grid reliability.
The role of storage
Energy storage will also play an important role in enabling the growth of solar and wind.
While there are many options for energy storage, pumped hydro being the most widely used, the rapid cost reduction of lithium-ion batteries continues to surprise industry experts and, combined with its modular construction and speed of installation, lithium-ion batteries are currently the energy storage technology of choice for most new applications.
Battery storage itself is not a new concept. But today’s developments are set to have a huge impact on the energy transition. In the next few years we can expect very significant growth in installed battery capacity, specifically to cope with variable renewables: we predict an installed capacity of around 50 TWh by 2050.
One example is the Hornsdale Power Reserve lithium-ion battery installation in Australia, which was installed in 2017 to address concerns about stability of the South Australian electricity system amid increasing penetration of wind and solar.
Compared to the 50 TWh of installed battery capacity to cope with variable renewables, we predict that global EV battery capacity will be around twice that level come mid-century. The additional battery capacity which will be needed to deal with variable renewables is very sensitive to how much of the capacity from EV batteries can or will be made available.
With batteries taking a more critical role in electricity supply, it will become increasingly important to ensure that the performance of these batteries can be reliably verified using independent data. Tools such as Battery XT a platform to compare different technologies, and evaluate expected lifetimes for specific applications, a huge competitive advantage for companies looking to differentiate in a growing market. As batteries become cheaper – which we anticipate they will –more will be produced and used. To satisfy the need to know which battery performs best there’s now a Battery Performance Scorecard which provides independent ranking and evaluation of battery vendors.
A multidisciplinary approach to tackle climate disruption
It’s clear that storage has a significant role to play when it comes to supporting the rise of renewable energy, but ultimately lowering our dependence on fossil fuels will take extraordinary effort and behavioural change, along with a combination of solutions working together, to ensure the energy transition accelerates and we limit the impact of climate disruption, before it’s too late.
Find out more about what our experts are doing across the energy value chain to support the energy transition by taking a look at the videos and profiles on our website. Or if you want to learn more about how innovation will mitigate the risk of Dunkelflaute, then Let’s Talk!