Today, one in four South Australian homes have rooftop solar panels and the numbers are growing rapidly. Network operators and suppliers predict that solar could soon supply the state’s entire energy needs. While this is good news for the solar industry and the environment, grid operators are viewing it as a threat to the grid’s energy security system.
Transmission network operators ElectraNet says the state was at its most vulnerable to another blackout event on days of "minimum demand" — that is, when consumers consume the least amount of power and all of that power is being drawn from solar.
"It could be as early as 2023 when the energy coming from rooftop systems in South Australia is all the electricity that state needs to run the grid," Australian Energy Council chief executive Matthew Warren said. He adds that this poses some technical challenges when it comes to keeping the grid stable. Warren explained that grid operators are faced with the challenge of maintaining a grid that is essentially a back-up as consumers switch to solar and batteries.
Renewables can support a grid-not break it
Energy security is a sensitive topic in South Australia. Wild weather recently left the entire state in the dark. Both Prime Minister Malcolm Turnbull and Energy Minister Josh Frydenberg have emphasised the importance of energy security.
Turnbull described the blackout as a wake-up call, suggesting that reliance on renewables places very different strains and pressures on a grid than traditional coal-fired power. The assumption that these politicians and others are working off is that South Australia’s wind industry weakened the state’s energy security.
But perhaps these politicians have got the wrong end of the stick when it comes to baseload power and the role of renewable energy. In a modern energy landscape, baseload power refers to power sources that continually generate electrical power, therefore meeting a minimum demand.
The underlying assumption is that the only way of supplying baseload electricity demand is by means of power stations, such as those fired by coal, that operate at full power all day and night. This is a widely held belief in Australia.
A former Australian industry minister, Ian Macfarlane, claimed that the only real alternative way that baseload power can be produced is by hydro and nuclear. But this does not hold true. In 2014 South Australia got 39% of its electricity from renewable energy (33% wind plus 6% solar). Consequently, the state’s coal-fired power stations have become redundant. Today, approximately 60% of natural gas in South Australia is used for electricity generation.
To date, despite a couple of teething problems, the system has operated reasonably well given the enormous transitional challenge.
It has strongly demonstrated the ability to achieve energy security via an energy mix that combines renewables, gas and a small amount of imported power from Victoria. The South Australian system also highlights the fact that baseload power is not synonymous with fossil fuels.
In this context, diversity of renewable energy sources is critical. Wind and solar are dependent on the weather to generate electricity but fluctuations in energy generation can be balanced with alternatives that can supply power on demand, such as hydro, concentrated solar thermal power (CST) or bio-fuelled open-cycle gas turbines.
Spreading out wind and solar PV farms also reduces this variation. Wind and solar must also be connected with new transmission lines to achieve wide geographic distribution and ensure diversity is promoted within the grid.
Smart energy management is another piece of the puzzle. Through the use of smart meters and consumer-controlled switches, it is possible to shave off peaks during periods of high electricity demand. These devices allow consumers to turn off power-intensive facilities, such as air conditioning, water or heating, for short periods when demand on the grid is high or supply is low.
More than just baseload
Energy security is not about traditional baseload power production. It is about the capacity of households, businesses and government to accommodate disruptions in the supply in energy markets. This is more than just about the weather-it highlights broader changes that are disrupting the energy sector.
Today, a secure and reliable energy future relies on energy diversity. Ideally, traditional baseload power will be replaced with a mix of renewable energy sources that together can achieve the equivalent of baseload power.
Improving storage for wind and solar production is a priority if its real potential is to be harnessed. Another priority is the improvement of connectivity between the states so that more renewable energy can traded across borders.
Microgrid technology will also be crucial since these have the capacity to disconnect from the traditional grids and operate independently of the grid. This is critical for areas that experience so-called super storms. This can help reduce grid disturbances and strengthen resilience. Microgrids essentially serve local energy loads and, in so doing, reduce losses in transmission and distribution.
Energy security strategies for the future
Some states have already implemented strategic groups to assess the growing energy security issues. One example is the Tasmanian Energy Security Taskforce which was implemented this year. Its aim is to examine how the state’s energy security can be strengthened and improved. The taskforce has just released a consultation paper which highlights the fact that energy security should focus on meeting long-term energy demand to a level of energy reliability that consumers will be willing to pay for.
The taskforce will examine the potential for reduced Basslink exports at high prices in Victoria, the costs of competing fuel sources for generation, and the costs associated with developing new generation and the associated system reinforcements. Basslink is a high-voltage direct current (HVDC) cable link crossing Bass Strait, connecting the Loy Yang Power Station, Victoria on the Australian mainland to the George Town substation in northern Tasmania. It can supply some of the peak load capacity to the mainland of Australia and take some of the excess base load capacity off the coal-fired generators on the mainland to supply Tasmania, leading to reduced pollution.
The Tasmanian taskforce seeks to examine a range of inter-related factors that include: progressing an energy mix in renewables; reducing energy security risks from extreme weather events such as storms and bushfires; and examining how much cost consumers are willing to assume to transition energy production to achieve a higher level of energy security for the state.
These developments show that energy security is not about going backwards to an outdated reliance on fossil-fuelled baseload power. Energy security is about new forms of baseload power and modern technology and business models supporting it.
Its success will ultimately depend upon the industry’s capacity to completely transform current energy systems in preparation for a new (cleaner and sustainable) energy future.