Wholesale Electricity Market (WEM) battery revenues are built from several moving parts, and pulling them together usually takes a lot of manual work.

Merchant revenues need wholesale prices, dispatch volumes and FCESS enablement. Total revenues then need Reserve Capacity Mechanism payments and Non-Cooptimised Essential System Service contracts layered on top. Without that full stack, it is easy to miss why two batteries facing the same market conditions recorded very different outcomes.

Ko brings these datasets together in the Terminal. It can pull price history, trace facility dispatch, compare merchant and contracted revenue, and show how individual batteries operated through specific market conditions.

What WEM market data does Ko have access to?

Modo Energy has synchronised Ko with WEM market data across four tables:

• wem_dispatch_prices: The 5-minute dispatch price for every interval from September 2023 to present. Includes the energy clearing price and all four FCESS market prices.
• wem_dispatch_facility: Per-facility dispatch volume at 5-minute resolution. This is the table for asset-level analysis.
• wem_tlf_values and wem_tlf_mapping: Transmission loss factors by facility and year. Used to transform at-station generation to grid-level revenues.
• wem_ncess_contracts, wem_reserve_capacity_prices, wem_supabase_capacity_credits: Contracted revenue data, NCESS contract values, Reserve Capacity Prices, and which facilities hold Capacity Credits in each capacity year.

You do not need to choose between these tables when asking Ko a question. Ko selects the right table based on what is being asked.

Why stay across WEM data?

WEM battery economics have shifted as more capacity has entered the market. FCESS prices have fallen, energy spreads have compressed, and the merchant revenue pool has become smaller. At the same time, contracted revenue through NCESS and the RCM now accounts for the majority of income for the assets that hold it.

As these conditions continue to shape the market, WEM operators and investors need a faster way to track the full revenue stack across energy, FCESS and contracted revenue.

How to analyse WEM market data

The examples below were produced by asking Ko questions against the WEM market data tables. Ko generated the SQL, queried the data, and produced the written interpretation. All charts were built from the same underlying data.

Output: Winter 2025 (Jul–Aug) saw the highest prices in that calendar year, peaking at $109/MWh in August — typical of the WEM’s seasonal demand patterns driven by heating load. November 2025 was a notable outlier on the low side at just $57.50/MWh, likely reflecting a combination of strong solar generation and mild demand.

2026 has picked up strongly, with prices climbing steadily from $84/MWh in January to a period high of $116/MWh in May 2026 — the highest month in the entire dataset. Note that these figures are simple arithmetic averages of all 5-minute dispatch interval clearing prices, so extreme price events (spikes or negative prices) are included and can move monthly figures materially.

Output: The overall trend is one of sharp and sustained decline across all four services.

Raise contingency dominated — then cratered. It was the highest-priced service throughout early to mid-2025, peaking at $48.67/MWh in May 2025, but has since collapsed to just $3.02/MWh in May 2026 — a fall of ~94%. The 2025 baseline was supported by frequent small scarcity events that have since been replaced by long periods at zero price.

Lower regulation and lower contingency flipped relative ranking. In early 2025, lower regulation was often priced above lower contingency. By late 2025 and into 2026, the gap between all services has compressed dramatically as the fleet grows and scarcity becomes rarer.

April 2026 was the low point across the board, with lower contingency and lower regulation both averaging below $0.30–$0.50/MWh — effectively near-zero support for batteries relying on FCESS revenue.

​Output: Collie BESS2 was the most active facility, accounting for around a quarter of total fleet discharge. Together, the six tracked battery facilities discharged approximately 91 GWh across the month.

The Collie cluster (ESR1, BESS2, ESR4, ESR5) collectively discharged around 63 GWh — roughly 70% of fleet output — while the two Kwinana units contributed the remaining ~28 GWh. It’s worth noting that despite the relatively high energy prices in May 2026 (averaging $116/MWh), the collapse in FCESS prices means batteries were increasingly relying on energy arbitrage rather than ancillary services to drive that throughput.

Output: RCM is the dominant revenue driver where it applies. COLLIE_ESR1’s ~AUD 4.27M RCM payment in a single month equates to ~AUD 21,350/MW, dwarfing its energy and FCESS contributions and putting its total at nearly AUD 23,400/MW for the month. KWINANA_ESR1’s ~AUD 945k RCM similarly lifts it to AUD 9,700/MW despite a negative energy position.

FCESS is critical for Kwinana ESR2. With a slightly negative energy position but AUD 1,768/MW in FCESS — the highest FCESS rate in the fleet — KWINANA_ESR2 appears to prioritise frequency services over arbitrage. Its raise contingency alone generated ~AUD 314k, consistent with a strategy of holding headroom for FCESS at the cost of energy dispatch.

ESR4 and ESR5 show negative merchant outcomes on the data available — net buyers in the energy market and no recorded FCESS revenue. This is likely explained by NCESS contracts: these facilities earn fixed availability payments outside the merchant streams tracked here, and their charging behaviour may reflect optimisation around those contracted obligations rather than spot market arbitrage.

​Output: The Reserve Capacity Price of $251,420/MW/year applies to both batteries under the current combined product. Only two battery facilities appear in the current-year CC data: Collie ESR1 and Kwinana ESR1. Notably, Kwinana ESR2 (which holds an NCESS contract) and Collie BESS2 do not appear — they may hold credits under the RCM that aren’t yet reflected in the data, or their credits may be offset/netted differently.

Collie ESR1 also holds an NCESS contract (Oct 2024–Oct 2026). Under AEMO Schedule 5, NCESS payments for that facility are netted against its RCM/RCP payments — so its net RCM revenue will be less than the ~$50.3M gross figure shown. The two separate credit products (Peak Capacity Credits and Flexible Capacity Credits) don’t take effect until Capacity Year 2027-28. Until then, all facilities operate under the single “combined” credit product.

​Output: The battery fleet shows a pronounced morning discharge peak, averaging 266 MW at 07:00 — the highest morning hour — alongside an energy price peak of ~$124/MWh. This reflects the morning demand ramp before solar generation ramps up.

Midday prices soften to a trough of ~$98/MWh at 10:00, consistent with the solar generation belly. Fleet discharge collapses accordingly, averaging just 2–10 MW across these hours as batteries shift to charging mode.

The dominant discharge event of the day is the evening ramp. Fleet output ramps sharply from 169 MW at 16:00 to a peak of ~438 MW at 18:00, tracking the evening price peak of ~$135/MWh at 17:00. This classic solar duck-curve response drives the bulk of battery energy revenue in the WEM.

Prices remain moderate ($106–122/MWh) overnight, but discharge is subdued — under 25 MW for most hours from 20:00 to 05:00 — suggesting the fleet is largely exhausted or holding capacity for the next morning peak.

Analyse WEM market data with Ko

When you're looking for WEM dispatch and revenue insights, Ko can quickly grab the data you need and turn it into the product you need. Ask a question in plain English, and Ko will identify the right table, write the SQL, and return results without any setup required. The live data covers September 2023 to present across prices and dispatch, with contracted revenue data spanning multiple capacity years.

Some questions to start with:

• How did WEM energy prices compare in the evening peak versus overnight in Q1 2026?
• What was Kwinana ESR1’s total discharge volume month by month in 2026?
• Which WEM battery facility had the highest dispatch volume on 28 April 2026?
• How have NCESS contract values changed between the 2024-25 and 2025-26 capacity years?
• What is Collie BESS2’s transmission loss factor, and how does it compare to Kwinana ESR1?