Smart grid performance indicators proposed for Europe

EU regulation requires national regulators to monitor the development of smart electricity grids but so far have lacked a common approach for assessing their real world performance.

Following a joint CEER, ACER guidance paper on smart grid performance indicators released in June 2004, the two organisations have now published detailed documents on smart grids at the transmission and distribution levels that are intended to provide a starting point for the national regulators.

The ACER paper addresses transmission smart grid infrastructure with the proposal of three core output indicators to measure infrastructure performance due to smart grid development:

• Performance of existing transmission assets in real-time system operations measured through comparison of the ampacity applied by TSOs in real-time system operation with the corresponding static ampacity on key grid elements such as lines and transformers. A value above 1 indicates that grid enhancing technologies or improved operational practices have increased the usable transmission capacity of existing assets.
• Performance in maintaining operational security measured through comparison of the actual annual costs of remedial actions (e.g. redispatch, countertrading) with the theoretical costs that would have been incurred under a standard baseline (e.g. static ratings, no smart optimisation). A value below 1 shows that smart grid measures reduced operational costs for maintaining operational security.
• Grid expansion performance measured through comparison of the actual total cost (capex and opex) of realised or planned grid investment with the theoretical total cost of a conventional investment (e.g. building a new line) that would achieve the same network benefit. A value below 1 indicates that equivalent outcomes were achieved more cost-effectively through innovative or capital-light solutions, including operational actions.

ACER recommends that the national regulatory authorities incorporate these indicators at the national level, with a two- to three-year transition period foreseen to establish data collection, modelling and reporting processes for methodological refinement and alignment across member states. 

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At the same time national TSOs are recommended to propose complementary input indicators reflecting the accessibility of tools (e.g. relevant smart grid technologies or operational practices) which impact the output indicators applied. 

ENTSO-E should support this process by providing guidance or reference mappings to promote consistency across member states.

Distribution grids

The CEER paper addresses smart grids at the distribution level with the identification of 14 indicators in six key dimensions of network performance:

• Integration of renewable energy generation with indicators overgeneration/curtailment of renewable energy sources, average connection time for new generation (per voltage level) and grid hosting capacity for renewable energy sources (injection).
• Integration of increased electrification of energy uses with indicators average connection time for new/increased loads (per voltage level) and grid hosting capacity for offtake (withdrawal).
• Continuity of supply and resilience to extreme events with indicators duration and frequency of long interruptions, frequency of short interruptions and risk-based indicator of the expected impact of extreme events.
• Other quality of supply objectives with indicators the type and amount of voltage quality events, average time to manage customers’ requests for intervention and availability of individual network assets.
• Energy efficiency with indicator distribution losses.
• Data made available to market participants with indicators online access to individual consumption and/or injection data and availability of 15-minutes withdrawal-injection network user data (from the smart metering system to suppliers/aggregators).

The paper states that the performance evaluation process and its output and input indicators enable the national regulators to assess historical performance and its evolution, establish the current situation and adopt a prospective vision to set desired targets and objectives. 

The proposed indicators and the performance evaluation framework could further constitute a sound basis for incentive regulation purposes.

CEER notes that the indicators are not static but are expected to be tested, refined and potentially adjusted over time, as experience is gained through their application and as data availability, methodologies and regulatory practices further develop.