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LearnETRM — Visual Explainer

Power Trading
PNL & MTM

How a German power trade on the EEX is captured, how volume aggregates to MWh, and how mark-to-market P&L is calculated when prices move.

EEX Exchange
Base + Peak Products
EUR/MWh Price Unit
MTM Valuation
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Chapter 01
01 — Products

Base load
vs. Peak load

Base load delivers power 24 hours a day, every day of the delivery month — including weekends and holidays. It's round-the-clock energy, typically cheaper per MWh because it includes low-demand off-peak hours.

Peak load covers only 12 hours on weekdays (08:00–20:00). No weekends, no holidays. Because it targets the highest-demand window, peak products command a premium price.

ETRM systems must treat these as separate volume streams with different hours and prices, then aggregate both to MWh for valuation.

00:00 02 12:00 22 06:00 18:00 08 16 BASE 24h × all days PEAK 12h × weekdays
Chapter 02
02 — Aggregation

Volume Aggregation

MW describes capacity. MWh describes energy delivered. ETRM converts capacity to energy: Volume (MWh) = MW × Hours/day × Days

Base
33,600 MWh
Peak
7,200 MWh
Base: 50 MW × 24h × 28 days = 33,600 MWh
Peak: 30 MW × 12h × 20 weekdays = 7,200 MWh
Total: 40,800 MWh
Chapter 03
03 — Valuation

Mark-to-
Market

Trade value = Trade price × Volume (MWh).
Market value = Current market price × Volume (MWh).

For a BUY trade: if the market price rises above your trade price, you have an unrealised profit. If it drops, you're sitting on a loss.

For a SELL trade, the logic inverts. MTM is computed per component (base, peak) and then summed.

Trade Price
€85
Market Price
€88
MTM P&L Formula
BUY: (Market − Trade) × MWh
SELL: (Trade − Market) × MWh

+€100,800 = (€88 − €85) × 33,600 MWh
Chapter 04
04 — Over Time

Price Changes &
P&L Impact

Markets move. At T0 (trade date), market price equals trade price — MTM P&L is zero. At T1 (say T+7 days), prices have shifted. The delta between new and old MTM reveals how much the position gained or lost.

Try it yourself
05 — Interactive

Calculator

Adjust the inputs below and watch volume, valuation, and P&L update in real time.

Trade Inputs
days
days
MW
MW
EUR/MWh
EUR/MWh
Market Prices (MTM)
EUR/MWh
EUR/MWh
Volume
Base hours
Peak hours
Base volume (MWh)
Peak volume (MWh)
Total volume
MTM Valuation
Trade value
Market value
Base MTM P&L
Peak MTM P&L
Total MTM P&L
Price Change Scenario (T+7)
Volume Aggregation (MWh)
Base Peak
MTM P&L by Component
Base P&L Peak P&L
Chapter 06
06 — After the trade

Settlement & Nomination

Mark-to-market P&L is only part of the picture. Once a power trade is executed, physical delivery must be arranged.

Scheduling & nomination — Power must be scheduled (hourly quantities per delivery day) and nominated to the relevant TSO (transmission system operator) or market operator by defined deadlines (e.g. D-1). The ETRM or a dedicated scheduling/nomination system sends these declarations and receives confirmations or capacity allocations.

Physical delivery — For physically settled contracts, the nominated volumes are delivered or received at the agreed delivery point. Imbalance between nominated and actual delivery can lead to imbalance charges.

Collateral & margin — Exchange-traded and cleared power positions typically require initial margin and variation margin. As MTM moves, margin calls may be issued; the ETRM and treasury must track collateral and funding. OTC positions may be subject to credit support (e.g. CSAs) and margin under EMIR or similar regimes.

Real ETRM implementations integrate with settlement, nomination, and risk modules so that P&L, delivery, and collateral are consistent end-to-end.

Important
Complexity & risks

MTM is theoretical — This explainer uses simplified MTM with no funding, collateral, or discounting. Volume aggregation assumes fixed days/hours and standard weekday definitions for peak; calendar and product definitions vary by exchange (e.g. EEX holiday calendars, German base/peak definitions).

Shape risk — Weekend vs weekday demand and prices differ; peak products exclude weekends, so actual delivery shape can diverge from a flat profile. Holidays reduce delivery days and change the number of peak hours (e.g. fewer weekdays in a month with many holidays). Load shifts (e.g. demand response, renewables) can move prices within the day.

Negative prices — In markets with high renewables penetration, prices can go negative; MTM and P&L formulas still apply but hedging and risk management become more complex.

Cross-border flows & congestion — Interconnector capacity and congestion can affect local prices and delivery; valuations may need to reflect zonal or nodal prices rather than a single reference price. Real ETRM systems handle settlements, nominations, risk limits, and these market specifics.

For German market specifics — EEX products, holiday calendars, and German baseload vs peak contract definitions — see German Power Trading (EEX & DE).