Operational Insights: Methodology
Operational Insights: Historical curtailment, revenue, transmission flows and headroom layered over the project pipeline for first-pass screening and asset benchmarking.
Operational Insights sits early in your workflow, bridging grid dynamics with the upcoming pipeline to enable rapid first-pass screening of sites, regions and assets without needing to connect separate datasets and tools.
Users can review historical signals, compare projects, lines and substations, and identify questions where deeper diligence or analysis is required. All in RenewMap’s responsive, easy-to-use platform.
These pages outline the methodology of the metrics provided by Operational Insights. This page gives a quick overview, while each metric has a full page with more detail.
Where the data comes from
All the operational data in Operational Insights is derived from data published by the Australian Energy Market Operator (AEMO) via NEMWEB.
Data sources & coverage sets out the update cycle and the time period, regions, units and equipment currently covered.
Project measures
Generation and Load
Generation (MW) is a unit’s average measured output, averaged over a half hour. Load (MW) is the same measurement from the other side of zero: how much the unit was drawing from the grid, which matters for batteries and pumped hydro that both charge and discharge.
Full derivation: Generation & Load
Curtailment
Curtailment is the gap between what a wind or solar generator could have produced and what it was actually dispatched to produce. It’s a measure of lost renewable generation that the market didn’t receive. This is reported as Network Curtailment if the unit was willing to sell at the price on offer and couldn’t, because a constraint was binding; Economic Curtailment is the share it priced out of the market itself.
Revenue and Missed Revenue
Revenue ($) values a unit’s output at the spot price that applied at the time, adjusted for transmission losses. It’s positive when the unit was generating and negative when it was consuming; and it can be negative while generating or positive while consuming, because NEM prices go below zero. Note this is Net Spot Revenue: it only includes revenue from the spot market, and subtracts spot costs for loads (e.g. battery charging).
Missed Revenue ($) is the same calculation applied to curtailed energy: what the output that never happened would have been worth. It’s the number that tells you whether curtailment actually cost anything, and it splits the same way curtailment does, so you can separate what a constraint cost from what a pricing decision cost.
Both figures are spot market outcomes only. They don’t include contracted revenue, FCAS, certificates or any cost of running the plant.
Full derivation: Revenue & Missed Revenue
Network measures
Line Flow and Ratings
Flow is the measured power flowing through a piece of transmission equipment, taken from AEMO’s telemetry.
A conductor can only carry so much current before it sags and heats beyond its design limit, so every piece of equipment carries a rating: Normal for continuous operation and Emergency for short periods after a contingency. Ratings are dynamic: they move with ambient temperature and equipment configuration, which is why you’ll see them change through the day and across seasons.
Full derivation: Line Flow & Ratings
Headroom
Headroom is how much more flow a piece of equipment could carry, as far as the market is concerned.
Equipment is limited by what the market is allowed to dispatch, and AEMO enforces that through constraint equations that often bind well before any individual asset reaches its physical limit, because of a contingency somewhere else on the network, a parallel path that would overload if this one tripped, or a group of assets sharing one limit.
Binding Hours and Marginal Value
Binding Hours records how long at least one matched thermal constraint was binding, shown as Hours and as a % of Time. It is a simple way to rank the parts of the network that are constrained most often.
When a constraint binds, the NEM dispatch engine reports its Marginal Value: the shadow price, in dollars, of that limit. It’s the answer to “if this limit were relaxed by one megawatt, how much cheaper would this dispatch interval have been?” A large Marginal Value is the market’s own measure of how expensive a bottleneck is.
Full derivation: Binding Hours & Marginal Value
Common questions
Each metric page ends with its own questions. Some questions you might have:
Getting started
- Why does my project have no operational data at all?
- Why does Operational Insights data stop at the end of last month?
- Is this settlement data?
- Why does history start in January 2022?
Reading the numbers
- Why doesn’t this match the number I get from another source?
- Is a low output day the same as curtailment?
- Why is revenue negative?
- Why is Missed Revenue zero when curtailment was high?
- Why do both flow directions have values in the same half hour?
- Why is Headroom lower than rating less flow?
- Why does my reconciliation come out half an interval off?
Gaps and blanks
- Why is Generation populated but Curtailment is blank?
- Why does that line have no operational data at all?
- Why is Marginal Value zero when the line looks full?
- What about projects in Western Australia?
Using it for a decision
- Can I use Headroom to size a new connection?
- Does this include PPA revenue, FCAS or LGCs?
- How do I compare congestion between two lines?
If your question isn’t covered, please get in touch.