Australia’s premier science body and the owners of the country’s electricity networks have put a lie to the conservative campaign against wind and solar, saying Australia could reach renewable energy levels in the high 90 per cent without compromising the reliability of the grid.
The CSIRO and the Energy Networks Australia also say that such grids will be cheaper than business-as-usual, and as a way of illustrating the pathway forward show how South Australia could be powered 80 per cent by wind and solar by 2036.
See also our story: CSIRO sees $100 billion savings in zero carbon grid by 2050.
The South Australia situation is deeply topical, because right-wing bloggers and think tanks, many in mainstream media and state and federal Coalition have used recent outages and price spikes in the state as an excuse to criticise wind and solar and state-based Labor targets that aim for 50 per cent renewables by 2030.
But the CSIRO and networks study – Electricity Network Transformation Roadmap – shows that way more than 50 per cent could be integrated into the grid without too much problem. By 2050, and Australia-wide, it could and should be in the high 90 per cent level for renewables, and nearly all of this will be wind and solar.
The report says that a range of new mechanisms will be required to ensure that the security of the power system is maintained as the sources of generation change at both the transmission and distribution level. And those initiatives should be put into place soon.
But this is how a three-day period in summer, and a three-day period in winter may look, with 80 per cent renewable energy in South Australia in 2016. (South Australia is already nearing 50 per cent wind and solar and will likely reach that point in the next 12 months).
In the summer scenario, nearly all the demand is met by wind, large-scale solar and rooftop solar, with battery storage and gas plants filling in the gaps. (Some have forecast that rooftop solar will meet all of daytime demand for the state on some occasions as early as 2023).
In winter, with less renewables in this three-day period, more gas is needed. What’s interesting to note is that “baseload” power, in this case combined cycle gas plants, are hardly needed at all. The system changes to one focused around renewables and flexible generation.
The report notes:
In the example shown for summer (Figure 21), excess energy will be produced in the middle of the day, some of which is transferred to battery storage. Overnight demand is met from battery storage, in combination with some baseload, peaking gas and a small amount of dispatchable biomass.
Figure 21 also indicates that on the third day it remained sufficiently windy overnight (green), which allowed for renewable diversity to meet the energy balance on that day without the need for other capacity.
In Figure 22, winter renewable output in 2036 can be observed as being lower than during summer, and as such the system producing less energy for battery storage during the day. This results in the system needing to utilise gas peaking plant much more during this period. It should be noted that this example could be modified to include other solutions such the deployment of further demand management or state interconnectors.
This example ultimately demonstrates that individual NEM region balancing is unlikely to rely on one single strategy or solution but will need to consider all possible combinations of solutions to provide a secure and reliable power system.
As more low emissions generation is installed, and in the absence of sufficient alternative strategies, consideration should be given to the needs of each NEM region. This includes if there is a need to specify a requirement for provision of firm capacity to meet the system security needs – the amount needed to deploy to support intermittent renewables in special circumstances.
Of course, wind and solar are not the only technologies. Battery and other storage technologies also thrive, as do smart controls. Electric vehicles become popular and micro-grids are also widely used. And the way the network is run also changes dramatically.
“Australia’s future power system must transform to become a sophisticated and intelligent network that will enable new and diverse technologies and services; increasingly dynamic markets and access to third parties; more active customer choice and control; and, new business models,” the report says.
This next graph illustrates the issue about minimum demand in South Australia any 2027 under different scenarios.
As this graph shows, by 2027 the state could be experiencing significant negative demand on certain days in summer months, largely as a result of solar – both rooftop and large-scale. Managing these swings, it says, will require close attention, both in the deployment of smart controls, storage and market design.
But other states will also have issues. This next graph shows that Tasmania could also reach near zero minimum demand by the same date. “This should not pose excessive challenges in terms of balancing and frequency control,” the report says, although careful planning will be needed.
Next is the graph that shows how the CSIRO and the network owners envisage the grid being powered by 2050. It is almost exclusively wind and solar, with a little bit of hydro, a tiny bit of gas, and storage.
The analysis assumes a primary role for storage in balancing the output of intermittent variable renewable energy.
The other solutions include the use of synchronous condensers, large-scale batteries, flywheel technology and emulated inertial responses from wind farms. Additionally, the distribution system is also a potential source of new ancillary services to support transmission-level system stability, and that means storage paired with solar on homes, business, and in communities.
While battery storage is forecast to provide the dominant new source of energy balancing, pumped hydro storage, ‘Power to Gas’ hydrogen storage, concentrated solar thermal generation, demand management and other systems could all play the same role.
