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Battery Arbitrage Revenue Calculator: BESS Energy Trading Income

Arbitrage is the most straightforward way a battery earns money: charge cheaply during off-peak hours, discharge at a premium during on-peak hours, and pocket the spread. But round-trip losses eat into every cycle, and how often you can actually run that cycle in a year depends on the local wholesale market and equipment constraints. This calculator estimates gross and net annual revenue from battery arbitrage, accounting for efficiency losses, operating costs, and your actual cycle count.

Usable energy capacity(MWh)
Round-trip efficiency 88%
Charge price — off-peak($/MWh)
Discharge price — on-peak($/MWh)
Cycles per year(cycles/yr)
Annual O&M cost($/MWh of capacity)
Revenue per cycle
$4,920

discharge revenue − charge cost

Gross annual revenue
$1,476,000

$4,920/cycle × 300 cycles

Annual O&M cost
$800,000

$8,000/MWh × 100 MWh

Net annual revenue
$676,000

gross − O&M

Net revenue / MWh / yr
$6,760/MWh/yr

net ÷ capacity

Results update live as you type. For planning and field-check estimates — always verify against applicable standards and equipment ratings.

How we calculate this →

How battery arbitrage revenue is calculated

Arbitrage math starts with a single cycle. You purchase your full usable capacity at the off-peak charge price — that is your cost. Round-trip efficiency (typically 85–92% for lithium-ion) determines how much energy you recover and can sell: a 100 MWh battery at 88% RTE delivers 88 MWh to the grid each discharge cycle. Revenue per cycle is (88 MWh × discharge price) minus (100 MWh × charge price). Multiply by annual cycle count for gross revenue, then subtract O&M to arrive at net.

The critical levers are the price spread and cycle frequency. A $60/MWh spread ($90 discharge minus $30 charge) at 88% RTE yields roughly $52.80 of net energy margin per MWh dispatched — but you need deep, consistent spreads and enough cycles to cover O&M. Wholesale markets with abundant midday solar generation are increasingly producing large price swings, creating better arbitrage opportunities, but the same forces that create those spreads can erode them as more storage participates.

Real arbitrage projects also carry market risk: forward price curves, curtailment, dispatch constraints, and capacity degradation all affect realized revenue. Battery developers typically stress-test spreads at 50–70% of historical averages and model cycle degradation effects on usable capacity over the project's 10–20 year life. This calculator gives the annual snapshot; a full project model layers in degradation, financing, and tax treatment.

Frequently asked questions

For a utility-scale 100 MWh battery doing 300 cycles per year with a $60/MWh spread and 88% round-trip efficiency, gross annual revenue runs roughly $1.6M. After O&M costs of around $800,000, net revenue is around $800,000 — about $8,000 per MWh of capacity per year. Results vary widely by market: PJM, ERCOT, and CAISO have historically offered better arbitrage opportunities than markets with flatter price curves.

Round-trip efficiency is the ratio of energy you can sell to energy you bought. At 88% RTE, a battery that charges with 100 MWh can only discharge 88 MWh — you pay for 100 but only earn on 88. A 5-point efficiency difference (88% vs 83%) reduces discharged energy by about 6%, directly cutting revenue per cycle. Over 300 cycles a year on a 100 MWh battery at $90/MWh, that's roughly $135,000/year in lost revenue.

Price spreads vary significantly by market and year. ERCOT (Texas) historically sees some of the widest spreads — $50–$150/MWh on average across the year, with occasional extreme events. PJM and CAISO see moderate spreads of $30–$80/MWh on a sustained basis. Markets with high renewable penetration tend to show larger midday-to-evening spreads as solar depresses midday prices. Developers typically underwrite projects at conservative spread assumptions and treat upside events as bonus revenue.