What is a grid-following inverter?

Grid-following inverters act as current sources that passively respond to voltage and frequency fluctuations, but rely on the grid being formed by its traditional inertial source: synchronous generators. An emerging solution to the low inertia of renewable-dominated power grids under intensifying climate risks is grid-forming inverters 103, 104.

Does grid flexibility and storage require high penetration of variable renewable electricity?

Denholm, P. & Hand, M. Grid flexibility and storage required to achieve very high penetration of variable renewable electricity. Energy Policy 39, 1817–1830 (2011).

How do renewables affect grid inertia & flexibility?

Grid inertia and flexibility (the two essential features that provide resilience against operational imbalances) are further constrained by high penetration of renewables. Renewable energy resources, such as solar photovoltaic systems, are integrated into the grid via power inverters.

How do transient power imbalances and grid inertia affect frequency change?

During the initial disturbance phase, for instance, within the first few hundred milliseconds, transient power imbalances and grid inertia jointly determine the rate of change of frequency — the time derivative of the power system frequency, prior to the response of system-wide automatic generation control for eliminating frequency deviations 48.

Are small power grids vulnerable to disturbances?

Whereas small power grids are generally expected to exhibit increased susceptibility to disturbances, it is less recognized that this vulnerability fundamentally arises from their deficiency in two different aspects of resilience: grid inertia 46 and system flexibility 47, which act at different timescales.