Characterize realistic minimum future hydropower dispatch

Characterize how low a realistic future minimum hydropower dispatch can be by separating the effects of energy-market requirements, frequency-stability requirements, and environmental restrictions on hydropower operation.

Background

The capacity-expansion energy-system model used for the future scenario imposes no minimum hydropower dispatch, whereas an alternative scenario imposes a 10% minimum at every bus and timestep. This assumption materially affects the availability and geographical distribution of dynamic reactive power and consequently the number of voltage-insecure contingencies.

The paper notes that historical minimum hydropower production reflects several potentially confounded drivers, including energy-market needs, frequency-stability services, and environmental limitations. Resolving their relative contributions is necessary to establish a realistic future dispatch constraint for high-resolution capacity-expansion and voltage-security studies.

References

However, it remains unclear as to how much of the historic minimum dispatch was influenced by energy market needs, frequency stability needs, and environmental limitations. This makes it difficult to say how low a realistic future minimum dispatch can be.

— Assessment of the N-1 voltage security of a future Nordic energy system  (2609.24356 - Kuhrmann et al., 21 Sep 2026) in Section 5, subsection “Hydropower modeling”