Energy Costs

Time-of-Use Tariffs: Timing Your Energy Use to Cut Costs

Guide · Commercial solar & battery · ~5 min read

Time-of-use tariffs price your electricity differently depending on the hour of the day, which means when you use power matters almost as much as how much you use. Get the timing right and you can trim a meaningful chunk off your bills without changing what your business actually does.

What a time-of-use tariff actually is

A time-of-use (TOU) tariff splits the day into pricing periods rather than charging one flat rate. The exact windows and rates depend on your network and retailer, but the structure is usually the same across the board.

Understanding which period you're in at any given moment is the first step to using power more cheaply. If your business runs heavy loads during the most expensive window, you're paying a premium you may not need to.

• Peak: the most expensive period, usually aligned with high grid demand.
• Shoulder: a middle rate either side of peak.
• Off-peak: the cheapest period, often overnight.
• Windows and rates vary by network, retailer and season, so check your bill or ask us to review it.

Why timing matters for your bottom line

On a flat tariff, a kilowatt-hour costs the same whenever you use it. On a TOU tariff, the same kilowatt-hour can cost noticeably more in peak than off-peak. For a business with predictable, shiftable loads, that difference adds up over a billing cycle.

The catch is that peak periods often line up with your busiest operating hours, which is exactly when you can least afford to switch things off. That's where a smarter strategy, rather than simply cutting usage, comes into play.

Practical ways to shift your load

Load shifting means running energy-hungry tasks during cheaper periods where your operations allow. It doesn't suit every process, but many businesses have more flexibility than they realise once they map out where their power goes.

• Schedule non-urgent equipment, pumps, charging or pre-cooling to off-peak or shoulder windows.
• Stagger start-up of heavy machinery to avoid stacking demand into the peak.
• Review timers, controls and automation so equipment isn't running expensively out of habit.
• Identify processes that genuinely must run in peak and treat everything else as flexible.

Where solar and battery storage change the game

Solar generates during daylight hours, which often overlaps with shoulder and peak windows, so it can offset your most expensive grid power directly. Pair it with a battery and you gain real control over when you draw from the grid at all.

This is where our AI-driven energy arbitrage comes in. The system can charge the battery when power is cheap and discharge, or export, when it's dear, effectively letting your site trade around the tariff rather than just react to it. How much that's worth depends on your tariff, load profile and network, which is exactly what a site review is for.

We install from 6.6kW right up to MW scale, in-house with no subcontractors, so the system is matched to how your business actually runs.

Getting the strategy right for your site

No two sites sit on the same tariff with the same load pattern, so the best approach is always specific to you. The starting point is understanding your current tariff, your peak demand and where your usage falls across the day.

From there we can model whether load shifting alone gets you most of the way, or whether solar, storage and arbitrage make a stronger case. Real numbers come from looking at your bills and your site, not from a generic rule of thumb.

If you'd like to see how a time-of-use tariff is affecting your business and what could be done about it, we're happy to arrange a site review and walk you through the options.

More: browse all guides · see our projects