What Is Energy Arbitrage?

Energy arbitrage means buying or storing electricity when it's cheap and using, selling, or exporting it when it's expensive. With a battery on-site, that price difference becomes a revenue stream in its own right, on top of whatever else the battery is doing.

Energy Arbitrage Meaning in One Sentence

Energy arbitrage is earning money from the gap between low and high electricity prices: you buy or store power when it is cheap and use or sell it when it is expensive. The "arbitrage" is the price gap, and a battery is what lets you move energy from the cheap hours to the expensive ones.

Why Electricity Prices Move

Wholesale electricity prices swing throughout the day based on supply and demand: cheap when renewable generation is high and demand is low, expensive during evening peaks when demand rises and gas plants set the marginal price. A battery that charges during the cheap hours and discharges during the expensive ones captures that spread, whether the discharged energy is used on-site, sold back to the grid, or offered into balancing market services.

How Energy Arbitrage Works, Step by Step

1. Forecast prices. Track wholesale and balancing prices to find the cheap and expensive periods of the day.
2. Charge when power is cheap. Typically overnight, or when renewable generation is high and demand is low.
3. Discharge when power is expensive. Use the energy on-site, export it, or offer it into flexibility services during the evening peak.
4. Net off the losses. Round-trip efficiency, battery degradation and fees decide how much of the price gap becomes margin.

A Worked Example (Illustrative Figures)

Take a battery with 1 MWh of usable capacity and 90% round-trip efficiency. Suppose it charges at £60/MWh and discharges at £140/MWh. It buys 1 MWh for £60 and, after losses, sells 0.9 MWh for £126, a gross margin of £66 for that cycle. These prices are illustrative, not a forecast: real spreads change every day, and the margin shrinks once degradation and fees are counted.

Why This Needs Automation, Not Manual Trading

Wholesale and balancing market prices move in patterns too fast and too frequent for a person to track and act on manually, especially across a portfolio of sites. An automated trading platform monitors live and forecast pricing continuously and dispatches the battery accordingly, charging and discharging on a schedule no manual process could keep up with.

Energy Arbitrage in the UK

In Great Britain, wholesale electricity is settled in half-hourly periods, so the price a battery sees can change every thirty minutes. Businesses can also respond to time-based price signals through half-hourly or time-of-use supply contracts, and the distribution charges on a commercial connection (DUoS) vary by time of day across red, amber and green bands. A battery that charges in the cheap periods and discharges in the expensive ones can capture value from all of these signals at once, which is why UK sites with solar, storage and EV charging often treat arbitrage as one revenue layer among several.

Whether the spread covers losses and degradation depends on your tariff, your connection and your route to market, so model it for your own site before committing.

One Battery, Multiple Revenue Streams

Arbitrage rarely stands alone as the reason to install a battery. It's usually stacked with other jobs, peak shaving, EV charging support, and virtual power plant participation, on the same physical asset, with software deciding moment to moment which job takes priority.

Energy Arbitrage vs Peak Shaving vs Flexibility Services

• Energy arbitrage earns from price differences over time, so its revenue depends on how wide the spread is.
• Peak shaving cuts a site's highest demand spikes to lower demand charges, so its value depends on the tariff and the load profile.
• Flexibility services pay a site for being able to change its power on request, for example through a virtual power plant or vehicle-to-grid.

Neutron's Energy Trading Platform

Our energy platform continuously monitors wholesale and balancing market prices and dispatches connected BESS assets automatically, layering arbitrage revenue on top of whatever else the battery is already doing for a site.

Is energy arbitrage profitable for a small battery system?

Profitability scales with battery size and how many price cycles it can trade per day, so small systems earn smaller absolute returns. It's rarely the only reason to install a battery; arbitrage is usually a secondary revenue stream on top of peak shaving or EV charging support, not the sole justification for the asset.

Do I need to trade energy manually to do arbitrage?

No, and in practice you shouldn't. Wholesale and balancing market prices move on timescales and patterns no person can track manually. An automated trading platform monitors prices continuously and dispatches the battery accordingly, without requiring someone watching a screen.

How do you calculate energy arbitrage revenue?

For each cycle, revenue is the discharge price multiplied by the energy sold, minus the charge price multiplied by the energy bought. Round-trip efficiency matters because you sell less energy than you buy. Multiply the margin per cycle by the number of cycles per day and per year, then subtract degradation and fees to get a realistic figure.

What is the difference between energy arbitrage and peak shaving?

Energy arbitrage earns from the difference between low and high prices, while peak shaving reduces the site's highest demand to cut demand charges. The same battery can do both, with software choosing which job pays more at each moment.

Can an EV charging depot do energy arbitrage?

Yes, if the depot has a battery and software that can charge and discharge it around the charging schedule. In a 25MW UK trial of an HGV depot, day-ahead optimisation and flexibility markets lifted depot profit by up to 9.88%, which we cover in our energy trading case study.