Nearly every Australian has felt the wild weather lately. Damaging winds, record rainfall, and record-breaking temperatures have recently hit South Australia, Victoria and New South Wales. These events caused power shortages, which have left over 100,000 households and businesses without power as hazards and energy demand exceeding supply have impacted energy infrastructure.
On the provision side of electricity, participants in the energy market are relentlessly working to keep the lights on. On the demand side, it seems like a no-brainer to turn our air-conditioning on to beat the heat, but it won’t be that simple, and we can do much more to support communities during these extreme times.
It seems like a nightmare, but it does beg the question: How will our electricity grid cope with the pressures of increasingly extreme weather? How do we moderate our energy consumption if there’s a chance power supplies can’t cope with our needs?
Demand is changing
Power is divided into demand-based categories – base and peak. “Base,” or average, is relatively constant and similar to day-to-day usage. Peak demand is the maximum demand and may only happen for a few hours on a few days of the year, like early mornings and evenings on 35+ degree days when air-conditioners are in full force.
Electricity demand in Australia is getting ‘peakier’ on average. We use less electricity daily as people and businesses become more efficient. However, more electricity is being used on particularly hot days, such as what we’ve seen in the past few weeks.
At the same time, demand is becoming a more active participant with the record installation of solar roof-top PV. These systems support household demand and are the main drivers behind lowering operational demand in the National Energy Market (NEM), which challenges how grids have traditionally been managed. We all have a role to play as energy system participants.
Supply is changing
There needs to be a change from our electricity generators, classified as ‘baseload’ or ‘peakers,’ to cope with our growing energy needs and climate targets.
Traditional baseload generators have been the steady, on-all-the-time electricity generators that supply constant electricity. In Australia, ‘baseload’ generators are usually large coal-fired power stations. Generally, baseload generators are fairly slow in changing the amount of electricity they generate. To match sudden changes in electricity from peak demand, we use ‘peaking’ generators, which are more flexible and dynamic in producing electricity. They quickly ramp up or down to match changes in demand and are usually based on hydro or gas generators.
However, the electricity that peaking plants (especially gas) produce is more expensive than baseload coal plants. The conventional solution has been to use cheaper coal-powered plants to supply baseload and more expensive gas plants (or hydro) to supply the variable peak component of our demand.
A role for renewables
We need a clean electricity supply that matches demand closely to ensure reliability and carbon emission commitments. Electricity systems worldwide show this can be achieved without ‘baseload’ using a combination of interventions:
- Flexible generation that can quickly vary its output, like wind and solar.
- ‘Demand management’ techniques that can vary electricity demand to match supply. For example, electricity loads such as hot water or pool pumps can be turned on/off, matching the available supply, and the consumer would never notice any change.
- Energy storage (for example, batteries or pumped hydro) to fill in any short-term gaps between supply and demand.
These concepts, matched with sophisticated load and generation forecasting schemes and careful control, mean that electricity systems can operate reliably with much renewable energy without needing baseload generation.
Managing your consumption
To keep our lights on and manage peak demand periods, there are small actions you can take to reduce your power consumption, such as keeping your air-conditioning temperature at 24-25°C, closing the blinds and turning appliances off at the switch. You can also use other passive techniques like draught-proofing, insulation, and landscaping to reduce costs and improve your home's resilience to extreme temperatures. If you have solar PV at home, techniques like pre-cooling can help you prepare your home for the evening heat. Households with batteries have the advantage of storing and using electricity when needed and greatly improve their resilience and autonomy during outages in case of bushfires and other extreme weather events.
Everyone has a role to play
Australia needs to be certain of what percentage of renewable energy our power system can cope with while staying reliable. Is it 40 per cent? 60 per cent? 100 per cent?
We don’t know how far this can be pushed, or more accurately, the trade-offs between cost, reliability and variable renewable energy penetration. A pivotal role exists for households, businesses, research institutions and industry in supporting the energy transition. As members of the last COP28 agreed, we need to double energy efficiency and triple renewable energy. Our ongoing energy research is focused on solving these challenges and ensuring Australia's secure, affordable, sustainable energy future.