REVIEW 3 major objections 5 minor 13 references
Contracting Strategies for Electrolyzers to Secure Grid Connection: The Dutch Case
T0 review · 3 major / 5 minor · reviewed 2026-08-07 · deepseek-v4-flash
Pith's one-line read Dutch electrolyzer grid contracts flip at a €10/MW curtailment price, a bilevel model shows.
desk verdict Well-structured bilevel model of Dutch CTA/CRC contracts, but the central 10 €/MW threshold result is unsupported because Eq. (2k) forces the key curtailment variable to zero. read the letter →
The pith
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
The reading
What carries the argument
The central mechanism is a pair of leader-follower games written as bilevel optimization problems: in the first game the electrolyzer owner leads and the network operator follows, and in the second game the roles are reversed. Each lower-level problem is reformulated using optimality conditions, with complementarity handled through special-ordered-set constraints and strong duality added to preserve optimality, yielding mixed-integer linear programs. The network operator's decision variables—connection capacity, NFA85 and NFA curtailments, and CRC/CRC+ activations—are what transmit the leader's choice into the follower's profit, so comparing the two hierarchies isolates who captures the surplus from congestion.
What would settle it
Re-run the numerical study with Eq. (2k) replaced by a budget inequality such as $\sum_{t\in T}\lambda^{crc+}s_t^+ \leq \theta B_{CM}$ for $\theta>0$, and inspect the electrolyzer profit curve around €10/MW; if the crossover and the profit reversal disappear or change sign, the paper's central threshold is an artifact of the zero-budget setup. Alternatively, compare realized contract choices of Dutch electrolyzer projects with CRC prices above and below €10/MW.
Extended reading notes
Core claim
The paper claims that the optimal grid contract for a Dutch electrolyzer is not fixed but flips at a curtailment-compensation price of about €10/MW. Below that price, the network operator's voluntary congestion management through capacity restriction contracts raises the electrolyzer's profit; above it, the operator curtails less and the electrolyzer is pushed into higher-tariff contracts, so its profit falls. The same regime change decides which player benefits from leading: above €10/MW, the network operator earns more when it reacts to the electrolyzer owner's connection choices than when it sets the connection capacity first. The paper also claims that dropping the game-theoretic structure, by optimizing only one side's objective over the other side's feasible region, overestimates profits for both parties.
Load-bearing premise
The reported sensitivity to the extra curtailment price assumes the operator has a budget to pay those activations, but the model as written sets that budget term to zero, so the threshold results depend on an uncorrected equation.
Editorial extensions
If this is right
- At CRC+ prices below €10/MW, voluntary congestion management can make an electrolyzer project more profitable and more likely to secure a grid connection.
- At CRC+ prices above €10/MW, the same mechanism lowers electrolyzer profit, so high curtailment compensation can backfire for the load.
- The network operator earns more by responding to the electrolyzer's contract choices than by leading them when CRC+ prices exceed €10/MW, so leadership positions change the value split.
- Ignoring the other party's optimization, as the high-point relaxations do, overstates profits for both sides, so coordinated game-theoretic treatment is needed to evaluate contracts.
- Lower hydrogen prices push the electrolyzer toward low-tariff NFAs rather than NFA85, making projects viable only with the tariff discount.
Reading between the lines
- If the €10/MW crossover is robust, regulators could use the CRC+ price as a policy lever: set it below the threshold to improve electrolyzer bankability, or above it to curb speculative congestion revenue, though the paper does not test this.
- The alternating-leader setup suggests the contract outcome depends on bargaining power; an auction or Nash bargaining model would be needed to say which hierarchy actually prevails in negotiations.
- The same two-level contracting logic could be applied to other curtailable industrial loads, where the threshold price would depend on their tariffs and grid residual capacity.
Signed reviews
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The paper models the contracting decision of an electrolyzer owner facing Dutch FA, NFA85, NFA, CRC, and CRC+ contracts as a Stackelberg game with two possible leadership orders. It formulates both games as bilevel programs, reformulates them via KKT conditions with SOS1/strong-duality treatment, and conducts a case study inspired by the GROWH project. The headline result is that voluntary congestion management (CRC+) increases electrolyzer profitability for CRC+ prices below €10/MW and decreases it above that threshold, and that the network operator prefers a reactive role at high CRC+ prices. The paper also compares the bilevel solutions with high-point relaxations to argue that ignoring the other party's optimization overestimates profits for both players.
Significance. If the model were correct, the paper would provide useful policy-relevant insight into the interaction between non-firm connection agreements and congestion-management contracts in the Netherlands, a topic with little existing quantitative work. The regulatory detail is translated carefully into a mathematical framework, and the use of KKT-based reformulations is methodologically appropriate. The model is not circular: parameters are taken from stated regulatory sources and are not fit to reproduce a target result. However, the principal quantitative claim is currently not derivable from the model as written because Eq. (2k) with θ=0 eliminates the CRC+ variable entirely, and the Game I relaxation of the binary variable is not justified. The central contribution is therefore unestablished.
major comments (3)
- [§III-B, Eq. (2k); §IV-A] With θ=0 set in Section IV, Eq. (2k), λ^{crc+} s_t^+ = θ B_CM, forces s_t^+ = 0 for every hour t whenever λ^{crc+} > 0. It follows that the CRC+ variables are identically zero and λ^{crc+} does not enter the effective objective or constraints of either bilevel program. The sensitivity sweeps in Figures 2 and 3, the comparison of EL-NO and NO-EL for CRC+ prices above €10/MW, and the abstract's regime-shift claim therefore cannot be reproduced from the model as documented. If the authors intended a budget constraint such as λ^{crc+} Σ_t s_t^+ ≤ θ B_CM, that correction is not stated and the numerical results would depend entirely on its specific form. This is a load-bearing internal inconsistency, not a modeling assumption.
- [§III-D(i) (solution of Game I)] The binary variable b_t in the lower-level problem of Game I is relaxed to [0,1] with the statement that this makes the lower-level problem linear and convex. No argument is given that the relaxation is exact: the original lower level is a mixed-integer linear program, and curtailments under NFA85 are tied to the number of activation days through constraints (2f)-(2h). Replacing b_t with a continuous variable enlarges the feasible set, so the KKT-reformulated solution may not be an equilibrium of the original game. This does not by itself invalidate the paper's central mechanism, but it means the EL-NO results in Figures 2-4, including the profit comparisons, rest on an unproven relaxation.
- [§IV-A, Figures 2-3] The narrative in Section IV-A repeatedly attributes the low-price behavior to 'curtailed via CRC+ at near-zero costs' and the high-price behavior to reduced CRC+ activations. These statements presuppose that s_t^+ can be positive, which is impossible under the stated parameterization θ=0. The interpretation of the threshold at €10/MW is therefore not supported by the model as written, independent of whether the first major comment's correction is adopted.
minor comments (5)
- [§III (end)] The sentence 'Note that all variable sets Θ(.) in both bilevel programs (3) and (5) belong to R+' is inaccurate because b_t is defined as binary in (2h); please clarify the exception or the intended relaxation.
- [§III-B, Eq. (2a)] The lower-level objective uses λ^{crc}_t and λ^{crc+}_t with a time index, while the parameters in Table II and Eq. (1a) are written without a time index; please make the notation consistent.
- [Figures 2 and 4] The axis labels in the provided manuscript are garbled (for example 'C¯ntrafit fiapafiities' and 'eur¯s'); please ensure the final PDF displays the labels correctly.
- [Throughout] The paper alternates between 'C10/MW' and '€/MW' for the same quantity; please use a single currency symbol consistently.
- [Eq. (1c) and (4e)] The upper-level constraints include lower-level curtailment variables such as s_t and r_{2,t}; as written this is a coupling through the follower's response, which is acceptable in a bilevel formulation, but the text should state this explicitly to avoid confusion.
Circularity Check
No load-bearing circularity; the bilevel model is constructed from regulatory inputs, with only a minor non-load-bearing self-citation.
full rationale
The paper's derivation chain is a bilevel optimization model whose inputs are regulatory parameters (tariffs, budgets, capacities, prices) and stated player objectives, and whose outputs — including the C10/MW CRC price threshold — are obtained by solving the model across a range of lambda_CRC+ values. No parameter is fitted to reproduce a target result, and no result is defined in terms of another result by construction. The only self-citation is [5] (shared co-author J. Morren), cited in the introduction as background on budget allocation for redispatch and CRCs; it is not invoked to justify the model, the reformulation, or the threshold claim, so it is not load-bearing. References [10] and [11] are external methodological and data sources. A serious internal inconsistency exists but is not circularity: Eq. (2k) states lambda_crc+ s_t^+ = theta B_CM for every t, and Section IV sets theta = 0, which forces s_t^+ = 0 for every hour; the reported sensitivity to lambda_CRC+ and the associated C10/MW regime claim therefore cannot be reproduced from the model as documented. That is a correctness or modeling defect, not a definitional equivalence between inputs and outputs. Similarly, absence of external benchmark validation is a validation gap, not circular reasoning.
Assumptions & free parameters
free parameters (5)
- λ_CRC (mandatory CRC price) =
40 EUR/MW
- B_NFA (NFA energy budget ratio) =
1
- B_NFA85 (NFA85 time budget) =
0.15
- θ (budget share for the electrolyzer) =
0 and 0.2
- λ_H2 (hydrogen price) =
10 and 5 EUR/kg
assumptions (4)
- domain assumption The interaction is a deterministic Stackelberg game with perfect information of the other player's optimization problem.
- domain assumption The proposed NFA contract with a daily energy budget B_NFA exists and is correctly parameterized.
- standard math The network operator's lower-level problem is convex after relaxing the binary variable b_t; strong duality and KKT conditions are applicable.
- domain assumption The residual capacity time series S_t and electricity price time series λ_t^e are known and represent a Dutch congested grid.
Cite this review
Pith. "Pith review of Contracting Strategies for Electrolyzers to Secure Grid Connection: The Dutch Case." pith.science (2026). https://pith.science/paper/VD4TZ7DY
@misc{pith2026250209748,
author = {Pith},
title = {Pith review of: Contracting Strategies for Electrolyzers to Secure Grid Connection: The Dutch Case},
year = {2026},
howpublished = {\url{https://pith.science/paper/VD4TZ7DY}},
note = {Machine review of arXiv:2502.09748}
}
read the original abstract
In response to increasing grid congestion in the Netherlands, non-firm connection and transport agreements (CTAs) and capacity restriction contracts (CRCs) have been introduced, allowing consumer curtailment in exchange for grid tariff discounts or per-MW compensations. This study examines the interaction between an electrolyzer project, facing sizing and contracting decisions, and a network operator, responsible for contract activations and determining grid connection capacity, under the new Dutch regulations. The interaction is modeled using two bilevel optimization problems with alternating leader-follower roles. Results highlight a trade-off between CRC income and non-firm CTA tariff discounts, showing that voluntary congestion management by the network operator increases electrolyzer profitability at CRC prices below 10 euro per MW but reduces it at higher prices. Furthermore, the network operator benefits more from reacting to the electrolyzer owner's CTA decisions than from leading the interaction at CRC prices above 10 euro per MW. Ignoring the other party's optimization problem overestimates profits for both the network operator and the electrolyzer owner, emphasizing the importance of coordinated decision-making.
Figures
Reference graph
Works this paper leans on
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[1]
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[2]
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[3]
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[4]
Codebesluit congestiemanagement | ACM.nl
“Codebesluit congestiemanagement | ACM.nl.” Available: https://www. acm.nl/nl/publicaties/codebesluit-congestiemanagement. Accessed Jan- uary 25, 2025
work page 2025
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[5]
The Activation of congestion service contracts for budget-constrained congestion management,
B. van der Holst, G. Verhoeven, P. H. Nguyen, J. Morren, and K. Kok, “The Activation of congestion service contracts for budget-constrained congestion management,” Electric Power Systems Research , vol. 235, pp. 110664, 2024
work page 2024
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[6]
F. Shen, S. Huang, Q. Wu, S. Repo, Y . Xu, and J. Østergaard, “Comprehensive congestion management for distribution networks based on dynamic tariff, reconfiguration, and re-profiling product,” IEEE Transactions on Smart Grid , vol. 10, no. 5, pp. 4795–4805, 2018
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[7]
Non-Firm grid connections for low-voltage generators: A case study in France,
L. Muller and F. Cadoux, “Non-Firm grid connections for low-voltage generators: A case study in France,” in the Proceedings of the 27th International Conference on Electricity Distribution (CIRED) , Rome, Italy, 2023
work page 2023
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[8]
Optimization for non-firm capacity contracts for maximized grid utilization,
K. K. Mehmood, R. A. Arruda Moura, A. Van Der Molen, R. Tonkoski, P. Van Der Wielen, and P. H. Nguyen, “Optimization for non-firm capacity contracts for maximized grid utilization,” in the Proceedings of the 7th International Conference on Electric Power and Energy Conversion Systems, Sharjah, United Arab Emirates, 2024
work page 2024
Show all 13 references
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[9]
Consultatie al- ternatieve transportrechten: use it or lose it,
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[10]
Why there is no need to use a big-M in linear bilevel optimization: A computational study of two ready-to-use approaches,
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[11]
Current status of water electrolysis for energy storage, grid balancing and sector coupling via power-to-gas and power-to-liquids: A review,
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[2022]
Accessed January 25, 2025
Available: https://www.acm.nl/nl/publicaties/ consultatie-alternatieve-transportrechten-en-use-it-or-lose-it. Accessed January 25, 2025
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[2023]
Accessed January 25, 2025
Available: https://open.overheid.nl/documenten/ ronl-7219ac2558977a6050ac4db764d2ddebb156df32/pdf. Accessed January 25, 2025
2025
Reviewed August 7, 2026 · model on record in the stance chip above.
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