Summer always pushes up business energy use, and this one is shaping up to be hotter than usual. With El Niño strengthening and the Bureau of Meteorology flagging an increased risk of heatwaves, air conditioning and refrigeration will be working harder for longer, often during the hours when electricity costs the most. A few weeks of preparation now can take the sting out of the bills that land in January and February.

What's different about this summer? In June the Bureau of Meteorology declared an El Niño, and its latest long-range forecast, issued on 1 October, says days and nights are likely to be warmer than average across almost all of Australia for the rest of the year. Unusually warm days are more likely in the south-east, and the Bureau expects El Niño to peak in late spring or summer.

Hot weather drives demand across the whole grid. During a heatwave last January, underlying demand on the east coast grid passed 40,000 megawatts, a record. The pressure point was the early evening, after solar output dropped away and prices became more volatile. That is exactly when many businesses still have cooling, cool rooms and equipment running flat out.

 

Why does hot weather push up your bill?

Most of the extra cost comes from cooling. Air conditioners and fridges have to work harder as the temperature outside climbs, and on a 38-degree afternoon they rarely get a break. A café's display fridges, a warehouse cool room and an office full of split systems all draw more power to hold the same temperature.

When you use that power matters too. Many business electricity plans charge more during a peak window. On Ausgrid's network, which covers much of Sydney, the Central Coast and the Hunter, the peak for small businesses runs from 3pm to 9pm on working weekdays from November to March. Other networks set different times, so check your bill or ask your retailer which windows apply to you.

Larger sites often pay a demand charge as well. It is based on the most power you draw at any one time during a set period, so one hot afternoon with every system running at once can lift that charge for the whole billing period, and on some network tariffs for months afterwards.

 

Start with last summer's bills

Before changing anything, pull out your bills from last December to February and put them next to a mild month like April or October. The difference gives you a rough idea of what summer costs your business. On each bill, look for:

  • your average daily usage, in kilowatt hours (kWh)

  • how much of that usage falls in peak times compared with off-peak

  • whether you pay a demand charge, and how high it went in summer.

If you have a smart or interval meter, your retailer can usually provide your half-hourly data, which shows exactly when your usage spikes. With that baseline in hand, it is much easier to set a realistic target and see whether the changes you make are working.

 

Get your cooling sorted before the first heatwave

Cooling is where most businesses can make the biggest difference, and the first steps cost very little. Book an air conditioning service now, before technicians get busy. Clean filters and coils let a system cool the same space with less effort, and a service picks up faults before they turn into a breakdown on the hottest day of the year.

Pick a sensible temperature and leave it there. Every degree cooler adds to running costs, and around 24 degrees is usually comfortable for staff and customers without overworking the system. Ceiling or pedestal fans make a room feel cooler, so you can run the air conditioning a little warmer. Pre-cooling in the morning, while it is still mild outside, also takes pressure off the system later in the day.

Only cool the spaces people are using. Close off storerooms and meeting rooms that sit empty, and look at shade on west-facing windows. Blinds, awnings and window film block heat in the late afternoon, which on many networks is also when peak pricing kicks in.

If you run fridges, freezers or a cool room, check the door seals and keep condenser coils free of dust, because both make compressors work harder. Strip curtains on cool room doors are a cheap fix for one of the biggest summer loads in food and hospitality businesses.

 

Work around the peak where you can

If your plan has a peak window, shifting even part of your usage outside it helps. Run dishwashers, laundry, battery charging and other heavy equipment in the morning or after the peak ends where your operations allow. Spreading big loads through the day, so several large machines aren't all starting up together, also keeps your highest reading down if you pay a demand charge.

It is worth agreeing on a plan for extreme heat days, too. Decide ahead of time which non-essential equipment can be switched off or delayed when the forecast passes 35 degrees, and make sure whoever opens up knows what to do.

 

Stop paying to cool an empty building

After-hours usage is easy to miss and adds up over a long summer. Walk through your site one evening after closing and note what is still running: lights, signage, air conditioning on a timer that no longer matches your trading hours, and computers and screens left on standby. Timers and smart switches are inexpensive and take the guesswork out of switching off.

 

Check your energy plan or contract before December

Your usage is one half of the bill. The other half is price: the rate you pay for each kilowatt hour, plus any peak and demand charges, which are set by your plan or contract. If you haven't compared recently, or your retailer moved you onto a new rate when a fixed term ended, there is a good chance you could be paying less.

For small businesses, comparing is quick if you have a recent bill, your ABN and your site address handy. A free bill comparison with Zembl takes about 10 minutes, and an energy expert compares your current pricing against options from a panel of leading retailers.

Larger businesses on fixed-term contracts should check when theirs ends. Going to market a few months before expiry gives you time to compare offers and lock in competitive pricing before the old contract lapses. Zembl runs an obligation-free tender with its retailer panel and presents the options for you to review.

 

Where to start

None of this needs a big budget. Servicing your air conditioning, moving a few loads out of the peak, switching off after hours and checking your rate before December can make a real difference to the bills that arrive after the hottest months of the year.