The discovery will quantify the value of the 'control approach' vs. the 'hardware approach' for guaranteeing stability in a decarbonised electricity grid:
• The control approach uses advanced monitoring and control techniques to access demand flexibility to support the grid, particularly flexible industrial loads and domestic loads such as electric vehicles.
• The hardware approach consists of investing in built-for-purpose assets such as grid-scale battery storage and synchronous condensers to provide ancillary services to the grid.
The control scheme offers regional sensitivity, particularly important in Scotland due to its low inertia. Customers could benefit from lower cost, and improvements to security and resilience of supply. For the benefits quantification, Imperial College's unique Ancillary-services Constrained Energy Scheduling (ACES) model will be used, in which regional ancillary-services dynamics are mapped into economic optimisation, enabling accurate quantification of the need for ancillary services in each region.
Investment efficiency is achieved through maximising the potential for existing grid customers and stakeholders to avoid large-scale investment in battery storage and synchronous condensers. Co-ordination of control and services across transmission, distribution, DERs and demand side delivers this benefit with minimal capital investment. Siting the response and controlling it in regional clusters minimises further network constraints that are a risk of the conventional approaches. Resilience is enhanced by the regional approach, providing a self-healing response by automatically rebalancing areas when severe weather events weaken the grid, while conventional approaches would leave large areas vulnerable to blackout if the grid is weakened or split.
SP Transmission plays a key role relating the whole system requirements of system operation with the distribution capabilities and the customers providing the flexibility. SP Transmission also has the most advanced transmission real-time monitoring system of the licensees and has established a worldwide reputation as an innovation leader in using this technology. Furthermore, the problem is particularly important in Scotland where the regional effects of inertia reduction are most critical.
GE will provide the design for the monitoring and control solution from its GB- based innovation centre for decarbonisation, specialising in fast wide area control as well as advanced transmission and distribution management.
Imperial College will provide the modelling and analysis expertise to assess requirements and benefits (technical and economic) for the proposed regional fast balancing service. The team will also specify the target participants for a follow-up demonstration.
The ESO, SP Renewables, SPD and SPM will all act as review authorities to verify the discovery outputs.
Problem Bring Solved
The future British power system will face a stability challenge due to the decreasing levels of inertia on the road to decarbonisation. Inertia, which refers to the rotating masses of synchronous generators, stores kinetic energy as it rotates to produce electric power; inertia is therefore a valuable energy buffer that helps maintain the grid in balance after an unexpected contingency, such as the loss of a large power plant. As coal- and gas-fired power plants retire or operate with lower load factors due to the increasing penetration of non- synchronous renewables (wind turbines and solar photovoltaic), this valuable energy buffer is reduced, potentially being close to zero during times of very high renewable power output. This presents a risk of instability in the future clean electricity grid.
New alternatives are needed to counteract the future low inertia, and an enormous opportunity is created by the electrification of demand: flexible loads ranging from large-scale industries to small domestic consumers could provide the necessary grid support to replace inertia in keeping the balance of the grid.
However, new control infrastructures and methodologies will be needed to access this demand-side flexibility, therefore an accurate quantification of the benefits from this approach is needed to unlock the necessary investment in this control infrastructure.
The urgency of using alternatives for grid stability is highlighted by the UK power blackout of August 2019. This event demonstrates that the threat to security of supply is increasingly significant as renewable penetration grows. This risk is even higher in weaker regions of the network, notably Scotland due to the wide deployment of windfarms replacing synchronous generators. Regional response to contingencies is becoming critical, which makes the current frequency stability services in GB inadequate. In this project, the benefits of the regional response approach will be quantified, considering a future competitive market design achieved by opening the market to future widely available assets such as electric vehicles. The main opportunity is to make use of existing devices in the demand side for supporting grid stability, a model that could be replicated in other grids outside the UK.
The implications of not taking this opportunity are significant: cost of ancillary services is projected to increase significantly by 2030 - to an estimated £1bn/year in GB. As such, this report will quantify the economic savings and carbon emission reductions generated by utilizing demand-side assets for these key services.
