electricity systems

Keeping costs low is essential as we move towards flexible electricity systems, write Gareth Davies and David Cox.

Decarbonisation and technological advances are transforming our electricity system, driving growth in distributed energy sources and making demand-side response a more accessible and flexible energy resource.

This article was originally published in Smart Energy International issue 2-2020 and appeared in the PEI – Supplement. Read the full digimag here or subscribe to receive a print copy here.

As we move towards a net-zero energy system, we are seeing two broad trends asserting themselves in the electricity sector. Firstly, the demand for flexibility is on the rise as renewables are contributing more and more to the energy mix.

Secondly, more of this flexibility will be located at lower voltage levels as the flexible, “on-demand” resource is provided by distributed generation and storage, electric vehicles and smart heat solutions. In a recent study for the Energy Systems Catapult in the UK, AFRY analysed how to efficiently and effectively manage this changing system in order to minimise operational costs.

As electricity systems evolve, we find that there is potential for electricity costs to rise for consumers. This is a result of a divergence in the timing of local and national electricity demand peaks, which leads to an increased risk of an inefficient system.

In this system, there will be more competition between the transmission and distribution system operators (TSOs and DSOs) for flexibility services which may only be operational for short time periods; for example, as batteries take time to recharge.

Without effective coordination between TSOs and DSOs, this divergence may increase overall network and generation investment requirements, generation costs and system balancing costs, ultimately increasing costs for consumers.

AFRY contrasted the effect of prioritising the use of distributed flexibility resource to meet national peaks, local peaks and having a fully integrated system.

Our outcomes showed that frameworks which enable a more coordinated use of resources could reduce system costs by up to £7bn by 2050.

When considering how best to manage new grid systems, we also found that the largest savings arise in frameworks where distributed flexibility sources are used primarily to address local network issues.

This enables DSOs to avoid a greater level of costly network replacement and reinforcement as there are limited close alternative flexibility options at the distribution level.

Managing the transition

It’s clear that there are substantial potential savings to be had; it’s just a question of how to get there. Any new arrangements should transparently reveal and respond to the true value (and cost) of using flexibility on the transmission and distribution systems.

As we transition to a more decentralised energy system and active DSO model, this means fundamental changes in the roles and responsibilities of transmission and distribution system operators; and the frequency and extent of information and data exchange between system operators and users to keep system costs down.

Such changes can be introduced gradually reflecting the evolution in the TSO-DSO relationship over time.

In the short term, the transition should focus on establishing a framework where the TSO can coordinate more effectively between the needs of local DSOs and the national system, improving information flows from DSOs on the local effects of national actions. Then, in the longer-term, more extensive changes – such as the emergence of local or regional flexibility markets – may emerge naturally as greater transparency and understanding of the value and accessibility of flexibility emerges.

Within this framework, it remains important to encourage more flexible resource use. Regulatory incentives should continue to encourage DSOs to consider innovative non-asset solutions to network issues. Harnessing the opportunities from the electrification of heat and transport will be an important part of this innovation.

For example, smart charging for electric vehicles could help to manage increases in demand and will help to balance the grid.

All in all, managed and considered shifts towards a more coordinated transmission and distribution electricity systems will ensure that we shield consumers from expensive, and inefficient, systems.

By moving towards new models of interaction, there is an opportunity for significant savings, but we recommend a careful and phased shift in the roles and responsibilities of DSOs and TSOs.

About the author

Gareth Davies is a Director at AFRY Management Consulting, advising on energy policy, regulation and market design across Europe.

David Cox is a Senior Consultant at AFRY Management Consulting, focusing on electricity network regulation and policy.