SUMMARY
GO prices rose across every technology in September, led by the 2027 vintage: WSH 2027 averaged €1.873/MWh (+13.1% MoM) against €1.684/MWh (+9.2%) for WSH 2026. Prices stepped up through the first three weeks to a 16 to 17 Sep peak (WSH 2027 €2.00/MWh), then held most of the gain into month-end rather than retracing as in August. The 2027 premium over 2026 widened from €0.09/MWh on 1 Sep to €0.24/MWh on 30 Sep, and the 2029 to 2031 vintages gained almost as much as 2027, leaving the current-year vintage as the laggard on the curve. Volume nearly doubled to 25.1 TWh across 357 trades (August: 13.4 TWh, 243 trades, same basis), with large multi-year WSH strips and a 1.43 TWh 2035 block reflecting forward coverage buying. Nordic Hydro posted the smallest gain of any technology on both vintages as Norwegian reservoirs refilled through the month. In North America, Mid-Atlantic non-solar RECs dropped on 4 Sep (PA Tier II -23.0% to $19.96/MWh, NJ Class II -14.7% to $22.38/MWh) while DC Solar rose in every week to close at $381.67/MWh (+7.5%), and Michigan's 13.6% fall on 25 Sep drove the Midwest basket's late-month decline.
MARKET ACTIVITY
Europe
- 357 trades and 25.1 TWh across 22 active days, against 243 trades and 13.4 TWh in August on the same basis (+47% trades, +87% volume). Excluding one 1.43 TWh WSH 2035-delivery trade at €1.595/MWh, volume rose 76%.
- W38 (14 to 18 Sep) was the busiest week at 108 trades and 8.3 TWh, above August's busiest week (W33: 104 trades, 5.2 TWh), and coincided with the price peak.
- WSH: 189 trades, 15.3 TWh, 61% of monthly volume.
- Hydro (non-Nordic): 49 trades, 3.3 TWh.
- Nordic Hydro: 55 trades, 2.9 TWh, up from 2.5 TWh in August.
- Renewable: 40 trades, 1.4 TWh. Wind: 13 trades, 0.95 TWh. Solar: 9 trades, 0.22 TWh.
- Nuclear: 2 trades, 1.0 TWh at €0.075 to €0.080/MWh, against a single €0.040/MWh print in August.
- Buying moved forward along the curve: the 2027 vintage share of volume rose to 24.4% from 21.3%, and the largest blocks were deferred WSH strips:
- 2028 to 2030: 900 GWh at €1.73/MWh.
- 2029 to 2031: 600 GWh at €1.70/MWh.
- 2026 Q4: 600 GWh at €1.71/MWh.
- Bids rose to 42 from 18 against 174 offers (August: 117). The market stayed offer-heavy, but buy-side participation more than doubled alongside the price step-up.
PRICE ACTION
Europe
- Every technology and vintage rose. The 2027 vintages gained 12.4% to 13.3% MoM, against 7.9% to 9.2% for 2026.
- WSH 2026: opened €1.51/MWh (1 Sep), closed €1.69/MWh (30 Sep), high €1.78/MWh (16 Sep); averaged €1.684/MWh vs €1.542/MWh in August (+9.2%).
- Weekly: €1.558 (W36), €1.678 (W37), €1.742 (W38), €1.724 (W39), €1.700 (W40).
- WSH 2027: opened €1.60/MWh, closed €1.93/MWh, high €2.00/MWh (16 to 17 Sep); averaged €1.873/MWh (+13.1%). The close sits above August's €1.78/MWh high.
- Weekly: €1.672 (W36), €1.862 (W37), €1.956 (W38), €1.932 (W39), €1.920 (W40).
- Nordic Hydro: smallest gain on both vintages; 2026 averaged €1.673/MWh (+7.9%) and 2027 €1.867/MWh (+12.4%). Its 2026 spread to WSH moved from +€0.008 to -€0.011/MWh on monthly averages.
- Hydro, Renewable and Wind tracked WSH: 2027 vintages averaged €1.873, €1.840 and €1.871/MWh (+13.1%, +12.9%, +13.3%).
- Vintage curve (WSH, 30 Sep): 2026 €1.69, 2027 €1.93, 2028 €1.84, 2029 €1.73, 2030 €1.71, 2031 €1.71. The curve now peaks at 2027; the 2029 to 2031 vintages gained €0.28 to €0.29/MWh open-to-close against €0.18/MWh for 2026.
- Volatility rose: WSH 2027 coefficient of variation increased to 5.92% from 4.05% in August.
- Trade-weighted averages in the table reflect vintage mix: the Nordic Hydro trade-weighted average (+12.2% MoM) carries heavier 2027 and 2028 volume than August.
North America
Mid-Atlantic
- DC Solar rose in every week, from $355.00/MWh (1 Sep) to $381.67/MWh (30 Sep), +7.5%; weekly averages $363.75 (W36), $366.88 (W37), $376.66 (W38), $377.33 (W39), $380.56 (W40).
- Non-solar credits fell in the first half of the month. On 4 Sep, PA Tier II fell $5.96/MWh (-23.0%) to $19.96/MWh and NJ Class II fell $3.87/MWh (-14.7%) to $22.38/MWh.
- PA Tier II held a $19.96 to $21.71/MWh range from 14 Sep and closed at $21.46/MWh (-20.4% vs 1 Sep). NJ Class II held $22.25 to $22.42/MWh from 15 to 29 Sep, then fell $1.34/MWh (-6.0%) to $21.04/MWh on 30 Sep (-21.0% vs 1 Sep).
Midwest
- Michigan held $4.92/MWh through 24 Sep, then fell $0.67/MWh (-13.6%) to $4.25/MWh on 25 Sep and held there to month-end, driving the basket's late-month decline.
Northeast/New England
CROSS-REGIONAL DYNAMICS
Europe
- Norway was the origin on 43 of 55 Nordic Hydro trades (August: 21 of 40). Norwegian reservoir filling rose from 63.4% at the end of week 35 to 66.6% at the end of week 38, remaining 18.3 percentage points below the 20-year median in week 37 (NVE); Nordic Hydro underperformed the basket over the same period.
- European and AIB GC origins accounted for 135 of 189 WSH trades, keeping the pan-European basket as the default instrument.
- Dutch-origin Wind and Wind/Solar printed at €3.91 to €4.16/MWh (170 GWh), more than double the €1.687/MWh Wind 2026 index average, extending August's €3.34 to €3.60/MWh Dutch wind prints. These trades are excluded from the averages above.
- Portuguese Solar traded at €1.19/MWh (5 trades, 106 GWh, 7 Sep), against €1.91/MWh for Spanish 2027 and €1.90/MWh for AIB GC 2028 Q4 Solar.
- Named national origins priced above the basket: Austrian WSH €2.06/MWh, German Renewable €2.06/MWh and French Hydro 2026 H1 €2.07/MWh (150 GWh), against 2026 index averages of €1.65 to €1.69/MWh.
Note: All figures, prices and market activity referenced in this report are based on the period 1 to 30 September 2026.
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