Why CurtailCast

Curtailment is not luck. It has an hour, a zone and a probability.

CurtailCast is under development: no forecast runs yet, and we are looking for producers to join the pilot. This page explains what the problem is, exactly what we will send you every evening, who it is for, and what we will not do. The examples on this page show what the forecast will look like — illustrative demo data, not live output.

The problem

At midday, generation exceeds what the system can absorb.

When PV and wind produce more than demand asks for and the interconnections can carry, ADMIE (IPTO, the Greek TSO) issues a curtailment instruction. Energy above the absorption line is never paid for. The weight falls in the midday window, 10:00–18:00 — which is where the forecast works.

RES generation against system absorption, a sunny Sunday Indicative values in MW per hour (demo). The orange area is the curtailment: generation above what the system absorbs.
See the data as a table
HourRES generationAbsorptionCurtailment
239

hours of zero & negative prices in Q1 2026 alone

12%

of RES generation expected to be curtailed in 2026

Sources: 239.5 hours of zero or negative prices in Q1 2026, based on ADMIE (IPTO) and ENTSO-E data — The Green Tank. The 2026 curtailment estimate of 3.3–3.7 TWh, i.e. ≈12% of RES generation against 7.5% in 2025, comes from a study by Prof. P. Biskas (AUTh) presented at POSPIEF — Solar Energy News, powergame.gr.

The solution

One email every evening. That will be the product.

At 21:00, once day-ahead prices and ADMIE's forecasts have been published, the model will run and send you what it expects for tomorrow: per zone, per technology, per hour. Below, an illustrative sample of the evening report (demo).

CurtailCast <forecast@curtailcast.com>
to: you

Evening forecast · example · High curtailment risk 11:00–17:00

Evening forecast · example · horizon D+1

Tomorrow

Day-ahead market prices have been published and are used as an input.

Zero or negative price hours: 0.9 h expected (no hour with P ≥ 0.5). Lowest hourly price (p50): 38.9 €/MWh at 11:00 · p10 minimum 33.8 €/MWh.

ZoneTech.scoreRiskmax Pexp. MWh-eqp90 peak MWwindow
Central MacedoniaWind0.52High0.663,1621,06411–17
ThessalyPV0.44High0.651,41952711–17
Central Greece / AtticaWind0.31Moderate0.686,4161,91511–18
Central MacedoniaPV0.27Moderate0.665,0991,62011–18
Western GreeceWind0.24Moderate0.681,70156611–17
Thrace / East MacedoniaPV0.08Low0.601355911–17

+ 6 more zones × technologies in the full email.

System: highest-risk window 12:00–16:00 (Greek time) · Σ expected curtailed power 24,026 MWh-eq · daily estimate p50 27,238 (p10 4,471 – p90 59,554) MWh-eq.

Probabilities refer to curtailed power > 0 (an ADMIE instruction below the reference) per zone × technology × hour. The MW figures are curtailed power, not lost energy. The score combines probability and expected magnitude; it is not the same as max P.
You will receive this email because you will be subscribed to the evening forecast. Settings · Unsubscribe

Illustrative design sample (demo).

What you gain

What the pilot will give you.

01 · In the pilot

Negative or zero price hours, one by one

For every hour of the next day, the probability that the market price drops to zero or below, and the price estimate. You will know which hours will cost you before they happen.

HourP(price ≤ 0)price p50 €/MWh
00:00–08:000.0076–81
09:000.0062
10:000.0344
11:000.1539
12:000.1740
13:000.1940
14:000.1340
15:000.1740
16:000.0244
17:000.0054
18:00–23:000.0078–82

Illustrative demo data · Stage A · input: day-ahead market prices (HEnEx via ENTSO-E). Marked rows (▲) have P ≥ 0.15.

02 · In the pilot

Curtailment risk per zone and technology

Seven mainland zones, PV and wind separately. For every zone × technology (PV and wind): maximum probability, expected curtailed power, p90 peak and the window of hours with P ≥ 0.5 inside 10:00–18:00. The risk tier comes from a score that weighs probability against expected magnitude relative to the zone's own history.

  • Lowscore < 0.15
  • Moderate0.15 – 0.40
  • High0.40 – 0.65
  • Severe≥ 0.65
Central Macedonia · Windscore 0.52 · High
Thessaly · PVscore 0.44 · High
Central Greece / Attica · Windscore 0.31 · Moderate
Peloponnese · PVscore 0.22 · Moderate
Thrace / East Macedonia · PVscore 0.08 · Low

Bars: the day's risk score. Illustrative demo data · Stage B. The score combines probability and expected magnitude relative to the zone's own history; it is not the same as the maximum probability.

03 · In the pilot

Two runs a day

A morning run at 09:00 without knowing tomorrow's prices, for those placing bids. An evening run at 21:00 with prices published, for those planning the next day.

Who it's for

For anyone who loses money when the sun comes out on a Sunday.

  1. 01

    Producers and park operators

    PV and wind in one of the seven mainland Greek zones. You want to know tonight whether they will curtail you tomorrow at midday and by how much, so you can schedule maintenance, cleaning, or simply not be caught out.

  2. 02

    Traders and bid desks

    The morning run at 09:00 will come out before day-ahead prices are published. It will give you the probability of hours ≤ 0 € and a price range, so you can place bids on an estimate instead of blind.

  3. 03

    Aggregators and FoSE

    You manage many parks across many zones. The zone × technology picture will show you where the weight falls tomorrow, so you can warn your producers with one message.

What we don't do

Five things we will not promise you.

A forecast is a probability, not a certainty. We would rather you knew the limits before you rely on it.

  • We will not forecast per park. Not yet.

    The forecast unit will be zone × technology (PV and wind). Mapping ADMIE instructions to individual parks is not public at that resolution.

  • We will not measure lost energy.

    ADMIE's monthly reports give curtailed power (reference minus instruction). The MWh-eq you will see is that, not what you would have produced.

  • We will not guarantee prices or hours.

    Every number will come with a probability or a range (p10 – p90). The track record will show how often we get it wrong.

  • We will not control your park.

    We will not connect to SCADA or inverters and we will not send instructions. We will give you information; the decisions stay yours.

  • We do not hide our sources.

    ADMIE, ENTSO-E, HEnEx, Open-Meteo and CAMS. Public data, which will be archived immutably, with an explicit check that no forecast will use information that was not available at issue time.

Roadmap

What is coming. None of this is available today.

  • In development

    Ten-day horizon (D+2 to D+10)

    A daily picture per zone beyond tomorrow: expected hours ≤ 0 €, minimum price, expected curtailed power — with lower accuracy the further out the horizon goes.

  • In development

    Public track record

    Every forecast compared against what actually happened, as soon as the first issues run.

  • In development

    Park and portfolio view

    Your parks on top of the zones, with the zone's risk mapped onto your own capacity.

  • In development

    Battery charge/discharge guidance

    Charging windows when the price drops and discharge windows when it climbs, from the same hourly forecasts.

  • In development

    Loss documentation

    An exportable monthly record of curtailment for compensation claims, once per-park mapping becomes reliable.

  • In development

    SMS and threshold alerts

    A message only when your zone's risk crosses a threshold you set yourself.

  • In development

    Keyed API

    The same forecasts as JSON for EMS and trading stacks, with a key per customer.

Early access

Join the pilot list.

Request pilot access