Energy demand is the term used to describe the consumption of energy by human activity. It drives the whole energy system, influencing the total amount of energy used; the location of, and types of fuel used in, the energy supply system; and the characteristics of the end use technologies that consume energy.
The energy trilemma
The energy trilemma is an important driver of energy policy. It points to the potential conflicts between security, sustainability and affordability, in other words, the difficulty in ensuring that the lights stay on, that the environment is not damaged and that energy is affordable and accessible. Thinking about energy demand as well as supply helps address the trilemma. Reducing the total amount of energy used is a very powerful way of controlling energy bills, improving energy security and reducing emissions.
It is important to recognise that energy is not used for its own sake but facilitates the performance of everyday practices at home, at work and in moving around. These practices, and the policies, technologies and infrastructures that underpin them are constantly changing and interacting with each other. The implication is that the study of energy demand is not just about people, policies and cultures, or about technologies, infrastructures and spatial organisation, but a combination and intermingling of these. Studying energy demand is therefore inherently inter-disciplinary.
When we talk about energy demand, we refer to all uses of energy: electricity, transport fuels and fuels for heating and industrial processes. Our current energy system is at the beginning of a period of massive change. In order to respond to the threat of climate change, we will probably need to eliminate fossil fuels from the UK energy system by the middle of this century. Energy efficiency has increased and demand in the UK has fallen significantly in the last decade, but this trend needs to be continued and reinforced.
Although critical, improved energy efficiency will not be sufficient; we will also need to move away from fossil fuels. In electricity generation, current trends are positive. The costs of wind and solar energy are falling rapidly, and therefore we are seeing higher proportions of renewables in electricity generation, allowing us to move away from polluting fossil fuels such as coal. However, including large amounts of renewables into electricity supply is not straightforward. Electricity supply and demand have to be constantly balanced and solar and wind are variable sources, making this balancing more difficult. Many people are working on energy storage solutions and these are improving. Greater flexibility in electricity demand, often called demand side response, can also help. This involves a much greater understanding of the timing of energy demand and how it can be altered, either by changing our energy practices (e.g. doing the washing at different times) or storing energy locally (e.g. in hot water tanks or electric vehicle batteries). There are some technologies that promise to manage demand through smart devices connected via the internet and smart meters to a smart grid. Significant social changes will need to accompany these technological changes.
We will also need to decarbonise the fuels we use in heating and transport. Electrification can play a big role in this. We are already seeing increased demand for electric vehicles and some electric heating. However, complete electrification of heating is unlikely, and there are similar issues in moving away from fossil fuels in freight transport, aviation, shipping and many industrial processes. It is therefore likely that new energy carriers such as hydrogen will be needed, raising new issues for energy demand research.
Studying energy demand at CREDS
From this we can see that are different ways of dividing up the study of energy demand. In CREDS it has been divided into three main ‘sectoral’ areas: transport (where, how and why we travel), buildings (how to achieve comfortable, healthy, energy efficient buildings) and materials (how industry could adapt their processes and materials). These are supplemented by three cross-cutting themes, namely: flexibility (the timing of energy demand), digital (the influence of IT on energy demand) and policy (understanding how public policy affects energy demand). We also have a specific focus on the decarbonisation of heating.
In addition to undertaking our own research, CREDS will provide an Energy Demand Research Network over the next five years, bringing together the UK research community and linking to international initiatives.