Gas Market

Overview

Natural gas plays a dual role in the Australian energy market: it is both a fuel for gas-fired electricity generation (peakers and base load CCGTs) and a commodity traded in its own right through the Short Term Trading Market (STTM). Energy Copilot tracks the gas-electricity nexus to help traders and analysts understand cross-commodity price drivers.

Short Term Trading Market (STTM)

The STTM is AEMO’s gas trading platform for three East Coast hubs:

Hub	Location	Daily Volume	Key Pipelines
Sydney Hub	Horsley Park (NSW)	~700 TJ/day	MAPS, SEA Gas, CityGate
Adelaide Hub	Pelican Point (SA)	~200 TJ/day	SEA Gas, Moomba to Adelaide
Brisbane Hub	Wallumbilla (QLD)	~1,500 TJ/day	Qld Gas Pipeline, SWQP

Dashboard Pages

STTM Hub Prices (`/front-office/gas-prices`)

Daily STTM commodity prices for Sydney, Adelaide, and Brisbane hubs ($/GJ)
Price chart with configurable time range (7d, 30d, 90d, 1y)
Hub-to-hub price spreads — arbitrage opportunities between hubs
LNG export netback price comparison (JKM / TTF adjusted)

Pipeline Flows (`/front-office/gas-pipelines`)

East Coast pipeline network diagram with flow direction and volume
Major pipelines tracked:
- Moomba to Adelaide Pipeline (MAP): Cooper Basin → SA
- South East Australia Gas Pipeline (SEA Gas): VIC → SA
- Queensland Gas Pipeline (QGP): Roma → Brisbane/Gladstone
- Eastern Gas Pipeline (EGP): Longford → Sydney
- Tasmanian Gas Pipeline (TGP): VIC → TAS

Gas-Electricity Nexus (`/front-office/gas-electricity`)

Scatter plot: STTM gas price vs NEM spot price for gas-heavy regions (SA1, QLD1)
Heat rate calculator: implied gas price given current spot price and CCGT heat rate
Gas peaker dispatch cost curve: at what STTM price do OCGT units become economic?
Marginal cost of gas generation: (Gas_price_$/GJ × Heat_rate_GJ/MWh) + Variable_O&M

Gas-Electricity Price Driver Analysis

Gas is often the marginal fuel in SA1 and QLD1, so the gas-electricity price relationship is tight:

# Implied marginal cost of OCGT generation
def ocgt_marginal_cost(gas_price_gj: float, heat_rate_gj_mwh: float = 10.5) -> float:
    """
    Typical OCGT heat rate: 9.5–11.5 GJ/MWh
    Variable O&M: ~$3–5/MWh
    Carbon cost: emissions_factor × carbon_price
    """
    fuel_cost = gas_price_gj * heat_rate_gj_mwh
    variable_om = 4.0
    return fuel_cost + variable_om

At a STTM gas price of $10/GJ, the marginal OCGT cost is approximately $109/MWh — this sets a soft ceiling on NEM spot prices in regions where OCGTs are the marginal generator.

LNG Export Impact

Australia is one of the world’s largest LNG exporters, with Queensland’s Curtis Island LNG trains (APLNG, QCLNG, GLNG) consuming significant gas that would otherwise be available for domestic use. Energy Copilot tracks:

JKM (Japan Korea Marker) LNG price in $/GJ terms
LNG export terminal utilisation (quarterly AEMO data)
Domestic gas reservation policy status

API Endpoints

# Current STTM prices
GET /api/gas/prices/latest

# STTM price history
GET /api/gas/prices/history?hub=sydney&start=2025-03-01&end=2025-03-21

# Gas-electricity price correlation
GET /api/gas/nexus?region=SA1&period=30d

# Implied heat rate from current prices
GET /api/gas/heat-rate?region=SA1

Gold Table Schema

-- gold.gas_hub_prices
SELECT
    settlement_date,        -- DATE: STTM trading day
    hub_name,               -- STRING: sydney, adelaide, brisbane
    commodity_price_gj,     -- DOUBLE: $/GJ commodity component
    uplift_price_gj,        -- DOUBLE: $/GJ uplift (system costs)
    total_price_gj,         -- DOUBLE: $/GJ total (commodity + uplift)
    allocated_quantity_tj,  -- DOUBLE: total volume allocated (TJ/day)
    ingest_timestamp        -- TIMESTAMP: when loaded
FROM energy_copilot.gold.gas_hub_prices
WHERE settlement_date >= CURRENT_DATE() - INTERVAL '30 DAY'
ORDER BY settlement_date DESC, hub_name;