▲ Sell / discharge─ Hold▼ Charge

Best sell windows

Discharge battery - peak price hours

16:00 - 21:0017.1 ct/kWhPeak
07:00 - 09:0013.2 ct/kWh

Best charge windows

Charge battery - cheapest hours

00:00 - 06:005.2 ct/kWhCheapest

Arbitrage spread

Estimated sell − charge margin

12.0 ct/kWh
Sell avg: 17.1Charge avg: 5.2

Euro cents per kWh (EPEX SPOT)

Solar suppresses midday prices in summer - charge 11:00-14:00, sell in the 17:00-20:00 evening peak. Overnight wind can briefly push prices negative.

Indicative profiles based on typical day-ahead market patterns (EPEX SPOT, OMIE, CAISO, ERCOT, NEM/AEMO). Actual prices vary every 30 min - always verify with live market data before programming your battery schedule.

How battery arbitrage works

Charge during off-peak

Buy cheap electricity (or use excess solar) to fill your battery when prices are lowest - typically overnight or midday when solar generation is high.

Hold through neutral hours

Avoid selling or drawing from the grid during mid-range price periods to maximise the spread between your charge and sell price.

Sell at peak price

Export your stored energy when demand - and prices - are highest. Evening peaks (16:00-21:00) are the most consistent sell window in most markets.

Understanding the price profiles

The hourly profiles shown are indicative average patterns derived from typical day-ahead spot market behaviour for each region. They reflect the seasonal and diurnal price shape you can expect, not a specific historical day. Key forces shaping each profile:

  • Solar generation - suppresses midday prices in high-PV markets (Germany, Spain, California, Australia)
  • Wind generation - keeps overnight prices low in wind-heavy grids (Netherlands, Texas, UK)
  • Heating demand - drives sharp winter morning and evening spikes (France, UK, Poland)
  • Cooling demand - creates summer afternoon peaks (Spain, Italy, Texas, California)

What affects your actual arbitrage return?

The price spread shown is the gross opportunity. Your net return depends on:

  • Round-trip efficiency - typical lithium batteries lose 10-15% in charge/discharge cycles
  • Time-of-use tariff structure - retail export rates may differ from wholesale spot prices
  • Grid connection fees - some utilities charge standing or export fees
  • Battery cycle life - each charge/discharge cycle contributes to degradation cost

A spread of 10 ct/kWh with 85% round-trip efficiency and a 1 ct/kWh cycle cost gives a net margin of approximately 7.5 ct/kWh per stored kWh - a meaningful return on a 10 kWh battery in daily arbitrage use.