Reference
Glossary
The energy-market terms behind NukeGryd, in plain English. If a label on any page isn't obvious, it's probably defined here.
Prices & units
- $/MWh
- Dollars per megawatt-hour, the price of one MWh of electricity. Every power price here is in $/MWh.
- On-peak
- The high-demand weekday hours (about 7am to 11pm). Our hub prices are on-peak, the window traders watch most.
- Hub
- A benchmark pricing location for a region (PJM West, Mass Hub). Like a regional index for power price.
- Henry Hub
- The U.S. benchmark natural-gas price, in dollars per MMBtu. Gas is the input fuel; power is the output.
- $/MMBtu
- Dollars per million British thermal units, the energy unit gas is priced in.
- Basis
- The price difference between two locations (e.g. a regional hub vs the benchmark). Requires a market-data vendor; not in EIA.
How outages move price
- Marginal fuel
- The last, most expensive plant needed to meet demand. It sets the price. Usually natural gas, which is why losing nuclear pushes price up through gas.
- Heat rate
- How much gas it takes to make power. Power price is roughly heat rate times gas price, so the dollar impact of a supply loss scales with gas.
- Implied heat rate
- On-peak power price divided by gas price. Shows whether power is rich or cheap relative to fuel, independent of gas swings.
- Spark spread
- Power price minus the gas cost to produce it, a rough generator margin.
- Tight / Long
- Tight means demand is close to available supply, so prices are jumpy and sensitive to any loss. Long means ample slack, so losses get absorbed.
- HDD / CDD
- Heating and cooling degree days, a measure of how cold or hot it is. They drive gas (heating) and power (cooling) demand, and therefore price.
What we project (nobody else does)
- Outage overrun
- How many days PAST its published duration an outage is expected to run. The operator files a return-to-service date; this is our projection of what actually happens, per unit, built from that unit's own last three scheduled outages blended with a fleet model. A +8 day overrun on a 1,200 MW unit is 9,600 MW-days the market has not priced.
- Projected outage start
- When a unit will actually come off line. Where the operator has filed a date we carry it; where nobody has filed one we project it. Refueling dates are not public, no regulator filing carries them, and they cannot be scraped.
- Forced-outage duration
- If a unit trips, how many days until it is back. A scram is the supply event nobody schedules, so the only question in the hour after one is when the megawatts return. Scored against each unit's own trip history.
- Accuracy score
- Our own forecasts marked against what actually happened, rescored every morning and published in full. 100 means the call landed within two days, decaying as the miss grows. It is a score out of 100, not a hit rate.
- Operational Excellence
- One 0-100 score for how well a reactor runs, computed from 27 years of daily records: capacity factor, forced-outage days, breaker-to-breaker streak, fuel utilization, refuel and startup duration and scram rate. Ranked against comparable units.
- Breaker-to-breaker
- A continuous run from one refueling outage to the next with no unplanned shutdown. The industry's own badge of a well-run reactor.
- Coastdown
- Deliberately letting power drift down at the end of a fuel cycle as the fuel depletes. It is the earliest physical signal that a refueling outage is close, visible before any schedule confirms it.
Nuclear supply
- Baseload
- Always-on generation (nuclear, coal) versus peakers that ramp up and down. This product tracks nuclear baseload availability.
- MW offline
- Capacity not currently producing, the core supply signal. Nameplate capacity minus what is generating.
- Capacity factor / Availability
- Generation divided by full capacity, as a percent. 100% means the fleet is running flat out.
- Refuel / outage
- A planned shutdown to replace about a third of the fuel and do maintenance. The date is set years ahead, and these are the scheduled supply dips.
- Scram / forced outage
- An unplanned reactor trip. The supply loss nobody scheduled, and the one our same-day NRC wire exists for.
- Overrun
- When an outage runs longer than scheduled, keeping supply offline past its expected return.
Our methods
- Scheduled vs projected
- Scheduled = a confirmed outage date from our sourced schedule. These are not public: we source them through the NukeWorker industry network. Projected = our model estimate where we do not yet hold a date. We always lead with scheduled.
- P10 / P50 / P90
- The confidence band on the forward curve. P50 is the central case; 80% of outcomes fall between P10 (low) and P90 (high).
- Price residual
- On-peak price minus its own recent (30-day) norm. Strips the gas/season level so we can isolate the effect of a supply loss.
- ISO / RTO
- The regional operators that run organized power markets (PJM, MISO, ERCOT, CAISO, ISO-NE, NYISO, SPP).
Missing a term? Tell us and we'll add it.