Ruwaida et al TSO-DSO-Customer Coordination Swedish Demonstration (2022)

Ruwaida, Y., Chaves-Avila, J.P., Etherden, N., Gomez-Arriola, I., Gürses-Tran, G., Kessels, K., Madina, C., Sanjab, A., Santos-Mugica, M., Trakas, D.N., Troncia, M. — “TSO-DSO-Customer coordination for purchasing flexibility system services: Challenges and lessons learned from a demonstration in Sweden.” IEEE Transactions on Power Systems, 2022 (DOI: 10.1109/TPWRS.2022.3188261). Funded by the EU Horizon 2020 CoordiNet project (grant 824414). This is the primary real-world paper behind the academic model in Source - Lind et al TSO-DSO Coordination Meshed-to-Meshed (2023) — that paper’s PTDF-based Local Flexibility Market formulation explicitly replicates the mechanism this paper describes first-hand.

Funding: EU Horizon 2020, grant 824414 (CoordiNet)

What the paper does

Presents the real-world TSO-DSO-customer coordination framework CoordiNet implemented in Sweden, in three parts: (1) a general classification of coordination schemes, (2) the Swedish implementation within existing Swedish markets, and (3) results and lessons learned from the winter 2019/20 and 2020/21 demonstration seasons in Skåne, Uppland, and Gotland.

Seven-scheme coordination taxonomy

Classifies TSO-DSO coordination along four dimensions (flexibility need — local/central/combined; buyer; number of markets; access level) into seven schemes: Local Market, Central Market, Multi-level Market, Fragmented Market, Common Market, Integrated Market, Distributed Market. This is a finer-grained taxonomy than the four-model EU classification (Separate SO / Sequential / Common / P2P) already documented in TSO-DSO Coordination — The Central Design Problem › EU taxonomy: four market coordination models — the Swedish demonstrator explicitly ran the Multi-level Market Model: separate, sequential markets, distribution level (regional + local DSO) cleared first, then the central (TSO) level, with the TSO retaining access to distribution-connected resources via forwarded unused bids.

The Swedish subscription mechanism, precisely specified

The paper gives the exact structure the wiki’s subscription-mechanism discussion has previously described only qualitatively:

• Four-part network charge: usage fee (SEK/kWh), regular capacity charge (SEK/kW, annual), temporary capacity charge (SEK/kW, weekly, revocable by Svk), temporary subscription usage fee (SEK/kWh) — “normally the highest part of the payment”
• When a temporary subscription IS granted: usage fee 220–250 SEK/MWh (varies by TSO substation)
• When NOT granted — the 2021 penalty tiers (previously only described in the wiki as “a penalty,” now precise): 560 SEK/MWh (1st hour of overrun in a day), 1,400 SEK/MWh (2nd hour), 2,800 SEK/MWh (all further hours with limit violations)
• Market timing (Fig. 3): DA local/regional flexibility market ~10:30 → DA wholesale spot GCT 12:00 → ID flexibility market opens 15:00 (after the TSO’s FCR market closes) → available until 2h before delivery → TSO mFRR market opens 15 min before delivery

Results — winter 2020/21, all three sites

A discrepancy against already-ingested wiki content: CoordiNet and TSO-DSO Coordination — The Central Design Problem currently cite Skåne’s average price as ~2,285 SEK/MWh (sourced from CoordiNet D4.7.2). This paper’s Table I gives 1,503 SEK/MWh for winter 2020/21 specifically. The likely explanation is scope: D4.7.2’s figure may be an average across all three demonstration winters (with more volatile pricing in other seasons), while this paper reports one winter in isolation — but that reconciliation is not confirmed from this paper alone. Both figures are now recorded in the wiki with their respective scope stated, rather than one overwriting the other.

Uppland detail (matches and confirms the Lind et al. 2023 model): the two TSO-DSO interface substations carry subscription limits of 205 MW and 87 MW respectively (292 MW combined) — the exact figures the academic meshed-to-meshed model used for its Uppsala case study. Winter 2019/20 → 2020/21 development: FSPs 5→11, transactions 196→538, contracted flexibility 96→243 MW, cleared volume 3,260→6,596 MWh, average price 220→235 SEK/MWh. Congestion-hours fell from 270h (no flexibility) to 179h (actual outcome, via the regional DA+ID flexibility market plus bilateral SGU-contracted flexibility); a duration-curve analysis (Fig. 6) shows that using even the “high-priced” unused bids could have brought this down to 25h — those bids were left unused because their cost exceeded the temporary-subscription fee, making activation not cost-effective.

Lessons learned (beyond what’s already in the wiki)

• Dual-market prequalification barrier: stricter mFRR prequalification criteria than the local flexibility market’s own criteria discouraged FSPs from qualifying for both — a concrete, named barrier to the value-stacking behavior TSO-DSO Coordination — The Central Design Problem › Value stacking: the opportunity that requires coordination otherwise documents only as a manual workaround
• Weekly availability contracts: FSPs guarantee availability during DSO-determined peak hours for the following week only — designed specifically to give FSPs planning flexibility in both product scheduling and pricing, addressing the “energy-only isn’t enough” remuneration problem
• Baseline/metering prequalification burden: legal treatment of metering data, baseline agreements, and locational information of aggregated resources required significant DSO+FSP effort, disproportionately burdening aggregators; no consensus emerged on metering data source (DSO vs. FSP)
• CoordiNet’s Swedish work fed directly into sthlmflex, a Common Information Model (CIM), and Sweden’s 2021 flexibility product catalogue

Minor discrepancy — demonstration partner list

This paper’s acknowledgment names Vattenfall Distribution, E.ON Energidistribution, Svenska kraftnät, Uppsala City, Expektra, and RWTH Aachen as demonstration partners — RWTH Aachen is not currently listed in CoordiNet‘s consortium table, and this paper’s list omits Energiforsk (which the wiki’s existing, presumably more complete D4.7.2-sourced list includes). Treated as additive (RWTH Aachen noted as an additional technical partner) rather than a correction to the existing consortium table.

Relevance to existing wiki topics

• CoordiNet — primary source for the exact subscription-penalty tariff structure, market-timing sequence, and winter 2020/21 results table; also the source of the Skåne price discrepancy noted above
• TSO-DSO Coordination — The Central Design Problem — the seven-scheme taxonomy adds a finer layer beneath the existing four-model EU taxonomy; the dual-prequalification barrier is new, citable evidence for the value-stacking section
• Source - Lind et al TSO-DSO Coordination Meshed-to-Meshed (2023) — this is the real-world paper that academic model explicitly builds on and replicates; the Uppland 205/87 MW subscription figures are now confirmed from a primary rather than secondary source