There are huge, irreversible changes happening within the energy sector.
One is a move to reduce fossil fuel use, to address climate and energy security concerns. Related to this is ‘electrification’: using electricity in applications where we previously burnt fuels (for example by transitioning to electric vehicles or heat pumps).
To ensure this electricity is ‘clean’, and to take advantage of huge reductions in costs over the past decade, much new electricity generating capacity will exploit solar and wind resources.
In the past, we could simply burn more or less fuel as demand for energy rose or fell, thus ensuring supply and demand were always balanced. Our future energy system must maintain this same reliability, whatever the weather.
Engineers across multiple industry sectors are developing solutions to ensure this remains true, even in an increasingly electrified, low-carbon system.
1. Energy storage
Storing energy is an obvious way to match supply with fluctuations in demand.
However, storing electricity is very different from storing fuels: it involves turning electricity into a different form of energy and then back again.
This has been done for years at large scale by utilising ‘pumped hydropower’. Electricity is used to pump water up into a higher reservoir, converting electrical to gravitational potential energy. Flowing this water back down through a hydropower turbine converts that stored energy back to electricity.
The current boom in energy storage is being driven by battery technology, converting electricity to chemical energy and back. As well as large-scale storage, battery technology has another advantage: it can tap into the trend to more ‘distributed’ energy (or ‘the Internet of Energy’), where the system increasingly uses small, localised assets in addition to big, centralised ones. Hence battery storage already exists as anything from huge, utility-scale installations to residential-scale ‘behind-the-meter’ ones.
Beyond pumped hydro and batteries, a whole array of other energy storage innovations are emerging too, each suited to different locations, scales and storage timeframes.
2. Clean hydrogen
Using renewable electricity to split water into hydrogen (‘green hydrogen’) is another form of energy storage. We can store hydrogen as a physical fuel, which may enable energy storage on scales which battery or other solutions cannot economically replicate. We can recoup the electricity by utilising hydrogen in a fuel cell, gas turbine or engine.
But interest in clean hydrogen goes far beyond just a ‘storage’ pathway.
Firstly, there are numerous other ways to generate hydrogen, for example, starting with natural gas or biomass. Secondly there are multiple end-use applications in which hydrogen can potentially contribute to a low-carbon economy: not just to store electricity, but to fuel transport, heat, and various industrial applications too.
This multiplicity of potential hydrogen pathways means it is a sector awash with diverse information and opinions - all of which can be difficult to sift through and make sense of!
3. Carbon capture, utilisation and storage (CCUS)
A third approach to decarbonisation is to continue using fossil fuels, but to capture the fossil carbon they release before it reaches the atmosphere. This has the advantage of retaining the already-in-place infrastructures and inherent flexibility of conventionally fuelled systems.
The captured carbon can be permanently stored back underground or utilised in products which would have otherwise required new fossil fuel extraction (anything from chemicals to building materials).
This is another topic which is both controversial and encompasses a variety of technological solutions and potential applications and pathways.
It’s also one which illustrates how different markets overlap and can be interdependent. For example, consider the fact that CCUS will be an essential requirement for planned projects seeking to produce hydrogen from natural gas (so-called ‘blue hydrogen’) to progress.
Making sense of the changing energy landscape
With so many options in play, but each often backed by specific interests and powerful motivations, it can be difficult to understand where the most realistic growth opportunities and risks really lie.
None of these solutions exist in a competitive vacuum, so their market contexts and the linkages between them become particularly important to understand. An independent view of each of them and their role in the bigger picture really matters.
Dr John Massey
IMechE trainer
To help widen understanding, identify market opportunities, and fill the knowledge gaps that bring business and commercial risks, the Institution has launched a new series of training courses focused on energy transition topics:
For more information, or to discuss specific training requirements, contact us at training@imeche.org or by calling + 44 (0)20 7304 6907.