The impact of energy system decarbonisation and decentralisation on Scotland’s electrical system

Traditionally Scotland’s energy systems have relied on large centralised sources. The Scottish Government is now pursuing a policy of smarter, local models.  

This project is part of looking at the the opportunities for, and implications of, Scotland moving towards smart local energy systems, driven by sustainable decarbonised energy resources.  The research team has developed the Energy Flow Scotland (EFS) toolset which draws on other models to quantify energy flows, including both the anticipated demand and likely supply of energy.

The models quantify predicted energy flows at a district level, allowing for analysis of local energy demand and resources at a local level under different future energy scenarios. We have used the EFS toolset to analyse different credible future scenarios for Scotland’s energy system.

Key findings and conclusions

• A highly decarbonised and decentralised energy system will require significant investment in the electrical distribution system to make it fit for purpose.
  Local areas that introduce a balance of new low carbon demand technologies (such as EVs and Heat Pumps) with low carbon renewable generation will reduce the impact on electrical substations and thus requirements to upgrade. Areas that connect significant volumes of new renewable generation, without an associated rise in EVs/HPs, will see large rises in exported energy.
• A rise in low carbon demand technologies will impact electrical distribution substations, with a high number requiring reinforcement by 2040. However, a more centralised pathway that revolves around the integration of renewable generation concentrated in areas of natural resource will incur greater overall additional electrical system capacity requirement, despite perhaps less electrical substations requiring upgrade.
• The electrical distribution system across rural areas will be impacted more than urban areas between 2018 and mid-2030s. However, a steady rise in low carbon demand technologies will result in a sharp impact on urban areas between mid-2030s and 2040.
• Meeting future carbon reduction targets may be achieved using either a centralised or decentralised approach. However, this analysis forecasts that it will cost roughly 2.6 times more to upgrade the electrical distribution system using a decentralised approach in comparison to a centralised strategy.
  

The interim summary report includes:

• Development of the EFS toolset of electrical, heat and transport demand models, and renewable generation models.
• Use of the EFS toolset to model how electrical energy flows may change at electrical grid supply points (GSPs) throughout Scotland under a particular 2030 electrified energy future scenario.
• Analysis of how decarbonisation and decentralisation may impact electrical flows at particular GSPs, as well as discussion on the distinct challenges and opportunities at both urban and rural areas.
• Description on how local energy balancing may be used to reduce the need for future network reinforcements.