Energiforsk 2026-1193 Unison Prissignal Timeffektavgift (2026)

Energiforsk Report 2026:1193, Unison prissignal för ökad flexibilitet — Timeffektavgift (June 2026) — the UniFlex project (programme Elnätens hållbara teknikutveckling och digitalisering). Authors: Emilie Andersson, Johan Bergerling, Magnus Lenasson, Magnus Lindén. Develops a unified hourly grid price signal that reflects both grid and electricity-market value, to promote demand flexibility. Case study on the Sala-Heby grid, applying Energicentrum Gotland’s capacity-based tariff pilot to the whole network.

Key claims

• Goal: a single, unison economic incentive — a time-based (hourly) capacity tariff (timeffektavgift) — that accounts for grid value and market value, so customers’ flexibility is steered coherently rather than by colliding signals. The design allocates forward-looking and residual costs by the customer’s network use, degree of flexibility, and use of microproduction/storage.
• Capacity-definition level matters: available capacity can be set at nätstation, fördelningsstation, or whole-grid (subscription to overlying network) level — each produces very different price signals.
• Locational signal: whether customers under different stations are allowed different prices based on local available capacity is a key design choice.
• Findings from the Sala-Heby application:
  • An hourly price based on nätstation-level capacity challenges can produce high price spikes for individual customers and wide dispersion in customer impact between stations.
  • If geographic time-differentiation is not applied — i.e. all customers in the grid get the same hourly price set by the low margin in some station — it can be perceived as unfair, since many customers face spikes without any local capacity shortage.
  • High timeffektavgift hours usually coincide with high spot prices. Mostly the highest demand charges merely add to already-high spot prices; only sometimes is a high total price driven mainly by the charge. Hours where total price >2 kr/kWh and the effektavgift is more than half: 51.
  • A low share of revenue comes from the “most expensive hours” — positive for DSO revenue stability.

Relevance to wiki

• The Signal Stack — Price Signal Collisions at the Customer DER — the unison-signal idea is a direct response to signal collision; the spot/effektavgift coincidence is evidence.
• Demand Response — effekttariffer double-edge; geographic differentiation as a design lever.
• Swedish DSO Tariff Reform — Three Parallel Tracks (2025–2027) — Track 2 (new effektavgift model): UniFlex dynamic/locational tariff as a design option.
• Companion: Source - Energiforsk 2026-1197 Konkurrensen om Efterfrågeflexibilitet Simulering (2026).