To free the Baltic grid, old technology is new again
Engineers and energy watchers examine how the Baltic states are breaking away from the Russian-controlled power system and integrating with the wider European grid, using technologies like synchronous condensers, flywheels and HVDC links to maintain stability. Much of the exchange focuses on how grid inertia, frequency control, and reactive power can be provided without traditional large thermal plants, and how flywheels and advanced inverters compare with batteries and pumped hydro for fast-response support. The conversation also highlights the political and technical significance of Europe’s highly integrated grid, recent large-scale disturbance events, and the broader challenge of running a reliable system with a growing share of weather-dependent renewables.
Grid inertia, synchronous condensers, and ancillary services
- Several comments stress that “grid needs big spinning generators” is outdated.
- Synchronous condensers (essentially large flywheel-alternator machines) provide inertia, short‑circuit current, and reactive power without being net generators.
- They stabilize frequency and voltage on very short timescales, buying time for slower resources to react.
- Clarification that this is about ancillary services, not bulk energy storage.
AC phase, frequency, and grid balance
- Phase differences across the grid relate more to power flows than physical distance; power tends to flow from leading to lagging phase areas.
- Frequency/phase deviations signal imbalance between generation and load.
- Lines overload when current exceeds design, causing protective trips and cascading rerouting.
- Voltage is managed via transformer tap changes (AC) or power electronics (DC).
Renewables, storage, and future operation models
- Discussion of shifting from “generation follows load” to “load follows generation” as renewables grow.
- Balancing tools listed: storage (batteries, pumped hydro, flywheels), dispatchable plants (gas, coal, nuclear), and demand-response (price signals, interruptible loads, EVs/V2G).
- Concern about variability of wind/solar; consensus that a mixed portfolio plus storage and demand response will be needed.
Flywheels vs batteries for energy storage
- Pro‑flywheel arguments: high cycle life, no chemical degradation, fast response, wide temperature tolerance, potentially long design life.
- Counterpoints: cost, engineering complexity (high RPM, vacuum, magnetic bearings, safety of large rotating masses), and limited energy capacity vs other storage.
- Some see them as ideal for very fast, short‑duration services rather than long‑term storage.
- A few companies and projects are mentioned as actively developing grid flywheels.
European and Baltic grid integration & geopolitics
- 2021 Continental Europe split event is cited as proof of strong coordination: rapid TSOs response, minimal outages.
- Debate over how much of this integration is an “EU success” vs broader regional cooperation; non‑EU countries are also part of the synchronous and HVDC-connected grids.
- Ukraine’s rapid connection to the EU grid and Baltic desynchronization from Russia are noted as major political/technical milestones.
- Some worry about physical vulnerability of key interconnects; others note reciprocal vulnerabilities (e.g., Kaliningrad) and new local generation/LNG in that exclave.
Control systems vs hardware solutions
- Argument that many stability services could be provided by existing inverters (solar, wind, HVDC, batteries) with better software and grid codes.
- Objection: for large, multi‑GW deficits after grid splits, only actual energy sources like batteries or fast plants can help, not just inverter control.
- Tension between using dedicated hardware (condensers/flywheels) vs fully exploiting inverter capabilities.