Daily guide · BG · 2026-08-16

Negative-price watch Bulgaria: this week's floor, and what's ahead

All numbers computed from the week's published auction results at publication and frozen — this article is an honest snapshot, not a page that rewrites itself. Reproduce via the API.

Bulgaria did not record a single negative-price hour this week. The floor held at 0 EUR/MWh, reached on 9 August at hour 12, which is the classic midday solar trough. Ten hours came in below 10 EUR/MWh, so downward pressure is present, but it stopped short of pushing prices under zero.

For readers, this is the distinction that matters. A market that grazes zero at noon but does not break through it behaves differently from one that regularly clears negative. Here the risk is concentrated in the middle of the day, and it currently expresses itself as very low prices rather than outright negative ones. Context from the year so far, with 584 negative periods recorded, shows the mechanism is far from absent over 2026 as a whole.

The concrete takeaway: watch the midday window, not the full day. With a modelled probability of a negative period over the next seven days at 0,99, the balance of evidence points to a breach being close rather than remote. Treat this week's flat zero floor as a warning line, not an all-clear.

When wind and solar produce more than a zone can consume or export, the day-ahead auction clears below zero — producers literally pay consumers to take power. Negative prices went from curiosity to structural feature across Europe, and for anyone with flexible load or storage they're the most interesting hours of the year. Here's where BG stands.

0

this week's floor (€/MWh), 2026-08-09 at 12:00 local

0 / 10

hours below €0 / below €10 this week

584

negative delivery periods in 2026 so far (BG)

The forward view

Our negative-price risk model (Brier-scored daily against climatology — record on /accuracy) currently puts the peak probability of a sub-zero period in BG over the next 7 days at 99%. That number updates daily via GET /v1/risk/negative/BG — a 14-day calendar of per-15-minute probabilities.

Never miss one again

The useful pattern isn't watching a dashboard — it's a webhook that fires when tomorrow's auction clears negative anywhere in your zone: 

curl -X POST -H "Authorization: Bearer YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{"event": "negative_prices", "zone": "BG", "url": "https://your-app/hook"}' \
  https://voltcast.com/api/v1/webhooks

It delivers seconds after the 13:00 CET publication, HMAC-signed. Journalists and analysts: the live BG tracker has the all-time records, monthly history and a CSV download — free to cite with attribution. For the systematic view (which hours, which seasons, how deep), the full 2015+ archive is one bulk export away.

Live BG prices → All daily guides → Start with Home →

Method & citation. Prices are hourly means of published day-ahead auction results (native 15-minute periods averaged; ENTSO-E/SMARD, attributed). Wholesale-price component only — grid fees and taxes come on top and vary by supplier. Cite as "Voltcast Research, voltcast.com/guides/negative-watch-bg-2026-08-16".

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