Energy security and gas security of supply require explicit choices on system robustness

The core of the issue lies not only in the availability of gas, but in its changing role within the energy system. Where flexibility was previously largely provided by domestic production and national reserves, gas increasingly functions as a dispatchable residual source within a North-West European energy system in transition. At the same time, dependence on international trade and market-based incentives has increased.

This shift is visible on both the supply and demand sides. The transition from domestic production to imports, with a growing role for LNG, has made availability and prices more dependent on global markets. At the same time, gas has become more closely intertwined with the electricity system, where it provides flexibility in response to fluctuations in wind and solar generation.

From a physical system to market-driven flexibility

With the Groningen gas field no longer acting as a system anchor, flexibility has shifted from physical capacity to market mechanisms such as storage and price signals. Under normal conditions, this system functions effectively: storage is filled when price spreads provide incentives, and international trade compensates for shortages.

At the same time, this system has its limits. Market functioning optimises for average conditions, whereas security of supply is determined by extremes. Capacity that is only needed in exceptional situations is commercially difficult to justify. This creates a tension between economic efficiency and system robustness.

A system that works, but is not inherently robust

The current gas system functions as long as several conditions are met: sufficient supply on international markets, effective price signals and stable market behaviour.

It is precisely here that vulnerabilities emerge. Gas storage depends on seasonal price differentials, which may disappear if international gas prices remain high during the filling season. LNG flows follow global price signals, meaning the Netherlands competes with other regions for available volumes. At the same time, gas demand is becoming less predictable due to its coupling with the electricity system.

The greatest vulnerability arises when disruptions coincide. Reduced physical flexibility, increased dependence on imports and stronger coupling with the electricity system reinforce each other.

Towards 2030: stronger interdependence with electricity

Gas-fired power generation continues to play an important role as a source of flexible capacity in an electricity system with increasing shares of wind and solar. During periods of low renewable generation and high electricity demand, gas demand may increase rapidly.

Towards 2030, this dynamic will become more significant. The phase-out of coal-fired power plants and increasing electrification will heighten reliance on flexible capacity. If alternatives such as storage, demand response, interconnection, batteries or carbon-free dispatchable capacity are not available in time, this role may increasingly be fulfilled by gas-fired plants.

This creates a paradox: while structural demand for gas is declining, dependence may increase in specific situations.

What does this require from policy?

Security of supply cannot be reduced to individual instruments such as storage filling levels, LNG import capacity or crisis measures. Ensuring both gas security of supply and broader energy security requires an integrated assessment of gas, electricity, international markets, flexibility and strategic reserves.

According to TNO, three elements are essential.

1. First, there is a need for structural improvement in integrated market and system insight. Decisions on gas storage, LNG, Groningen, dispatchable capacity and electricity security of supply cannot be assessed in isolation when their effects converge within the same energy system.
2. Second, explicit choices are required regarding the desired level of system robustness. What level of dependence on international markets is acceptable? What degree of redundancy is needed? Which risks should be borne by market parties, and which by government or society?
3. Third, decisions with critical timelines must be assessed in a timely manner. This includes choices regarding the potential retention of physical fallback options around the Groningen field as an emergency provision, the role of strategic reserves and the implications of the coal phase-out for dispatchable capacity and gas demand towards 2030. Safety, affordability, sustainability and societal interests must be considered in conjunction.

Accelerating energy efficiency, renewable generation, storage and other carbon-free flexibility options structurally reduces dependence on gas. Precisely for that reason, it is essential to explicitly define the required level of robustness for the remaining gas demand during the transition phase.

Towards explicit choices on robustness

Current policy combines market mechanisms with standards and crisis instruments. This provides support in situations of acute shortages, but leaves open the question of how robust the system as a whole should be.

The analysis shows that making explicit choices on system robustness is becoming increasingly relevant. Without such choices, a system may formally comply with standards while remaining vulnerable in practice to coinciding risks.