The state-wide black-out in South Australia on October 28th was a warning sign of the most dramatic type. Our energy systems are changing faster than we know how to deal with. And our politicians, try as they may, are struggling to keep up with the changes.
Let’s take a look at the facts:
In 2009 the SA government set the state on a path to 33% renewables by 2020. This prompted the installation of solar and wind generation at unprecedented rates and that target was lifted to 50% in 2014. SA has the second highest penetration of rooftop solar per capita and over 40% of its energy came from its 16 large scale wind farms in 2015.
In Australia’s National Electricity Market, the least expensive generation gets dispatched first. Since there is no fuel cost for wind farms (unlike coal or gas, the wind is free!), they offer their energy cheaper than fossil-fuel based generation. As a result, the financial case for fossil generation has eroded over the past decade, which has prompted the owners of existing fossil-fuel-based generators in South Australia to moth-ball or retire several units. Since wind is an intermittent resource, the power connection to Victoria was beefed up in order to make up the supply gaps during periods of low wind production.
At 16:17 the epic storm took out one 275 kV transmission line. These are the lines which take the power from the generators to the cities where it’s used.
At 16:18 another 275 kV transmission line collapsed.
One second later, five wind farms reduced their output as a protection mechanism to avoid damage to the individual turbines.
Four seconds after that, a third transmission line was taken out by the storm. Two seconds later another two wind farms reduced their output.
Four seconds after that, the rapid reduction in South Australian wind power called on the power connector with Victoria to increase power flow in to South Australia. The amount required was higher than what the connection could provide which meant it ‘tripped’ offline. Essentially, it was over-loaded so it shut down.
With all these lines out, the power couldn’t flow and the entire state was cast in to darkness.
What our pollies have failed to adequately grasp is that the reduction in output from the wind farms and the transmission lines falling over are unrelated. That is, the blackout would have occurred if the state was entirely powered by coal or gas because the poles and wires required to transport the energy were down. Whatever your view of wind energy, that fact remains. Indeed, just this week the AFR reported that a top engineer at Seimens (the manufacturer of some of the wind turbines that took themselves offline) has stated that the same protection mechanisms would have kicked in whether the power was coming from a gas plant or a wind turbine.
So what have we learned from the events of 28th September? Despite the best effort of those who manage our energy system (and in general they do a phenomenal job), our power systems are vulnerable. Since several large industrial users went without power during the storm and the subsequent repairs, the estimated cost to SA is in the many millions of dollars. So the business case for increasing the security of supply is not hard to make. But how do we do that?
Interestingly, there are a few examples of South Australians who’ve taken the plunge and invested in energy storage for their homes. Reneweconomy reports on one such individual who unknowingly rode through the blackout with his power still being supplied by his battery! His family only realised the blackout had occurred from seeing reports on social media!
The most resilient grid would have batteries dispersed throughout the network so when one section of the poles and wires go down, the lights still stay on. So called microgrid clusters would be a much more economical way of building our network if we started from scratch today. Instead of large-scale generators far off on the horizon, with huge wires to channel the energy in to our cities, we’d have a network of distributed generation and storage. Where would the energy come from? How about the 1.5 million Australians with solar on their roofs. Household solar in Australia is growing at 10–20% PA so in 5 years, that’ll be around 3 million roofs with solar.
The transition to this brave new world will not be an easy one, though, with many unable to install solar whether because they can’t afford it, they rent, or they live in apartments. What if those with excess local energy could sell their energy at competitive rates to those looking for cheaper, cleaner energy in a ‘set-and-forget’ way? This brings the overall cost of energy down for everyone, and reduces the need for the large dirty generators, and transmission lines that can’t handle a strong breeze ;). This future is far more resilient that the current system, and my company Nexergy is working to make it a reality.
Our pollies say we need to reduce intermittent renewables to safeguard our energy system from events like what South Australia experienced last month. Next time I bump in to Prime Minister Turnbull I think I’ll mention that we actually need to increase the amount intermittent generation resources on our grid and distributed batteries are the facilitator. In fact, increasing customer choice through a peer-based Local Energy Trading platform is the way to do it.