Wind supplied 47% of South Australia’s energy last week

As I write these words, 7.4 per cent of the electrons powering my laptop come from wind farms – travelling at the speed of light between hundreds of silently whirring generators and the complex electronics in my computer. The output of wind farms over the past nine days – the span of National Science Week – has been particularly excellent, and it’s worth diving into some data to have a closer look.

Screenshot taken at 12:30 AEST 19/08/2013 from www.mistervint.com

Science Week was from August 10-18, inclusive. The Australian Energy Market Operator (AEMO) makes 5-minute generation data available through a gargantuan database. I’ve chosen to focus on South Australia and Victoria, states which lead the way in installed wind generation – there are 22 wind farms I’ve obtained generation data for, summarised in the table below.

The total generation of those 22 wind farms was 285,257 megawatt hours. But what does that deliver to the energy market? The average Sydney household consumes 11.6 KWh per day, or 0.104 MWh over 9 days. So, the generation of wind farms throughout science week could power ~2.7 million homes – enough for all of Greater Sydney, and all of Greater Adelaide. That statistic alone is a firm reminder that wind power is a formidable player in the supply of energy.

Wind farms regularly contribute a large quantity of energy to the electricity market. We can chart total power output, every five minutes, over the course of Science Week:

Wind power is already regularly crowding out generation from fossil fuels, and Science Week is a great example of this. Looking specifically at South Australia, we can compare wind power generation to demand:

Wind power was a key player in generation, over Science Week. South Australian demand was 339.51 GWh over the course of the nine days, and total SA wind generation was 157.07 GWh – meaning wind supplied 46.26% of total energy in South Australia. South Australians ought to be proud – the integration of wind energy into their supply mix has been largely seamless, and in FY12, ~24% of total energy was sourced from wind. Victoria’s installed wind capacity is much lower, and coupled with Victoria’s significantly higher demand, wind plays a smaller role in offsetting fossil fuel generation:

Victorian wind power generated at close to full capacity for a large portion of the week, and at 05:55 on 18/08, wind power in Victoria was at 826 megawatts and demand was at 4,365 – during this interval, wind was powering nearly 1 in 5 homes in Victoria (18.9% of demand). Though this occurred during a period of low demand, these statistics give us a glimpse of the huge quantity of energy Victoria could source from wind power, something that’s currently being scuttled by Victoria’s draconian and non-scientific planning laws.

The power generated by wind crowds out the burning of fossil fuels. The 285GWh of energy that was pumped into the grid over the course of Science Week would otherwise have been sourced from traditional fuel sources, such as black or brown coal. You’d need 415,423 tonnes of brown coal, to generate that energy using fossil fuels (assuming a heat rate of 15 GJ/MWh and an energy density of 10.3 GJ/tonne).

As part of the Australian Museum’s Science Festival last week, we set up a booth adorned with a small solar panel, a wind turbine model, and a few displays showing real-time data from our wind farms, and wind farms across the NEM. One particularly inquisitive kid walked up to our booth, and paused briefly, gazing at the multitude of screens and the slowly-rotating wind turbine model behind.

“It’s generating a lot now, but doesn’t wind speed change all the time? What are we meant to do when there’s no wind power?”

It was oddly refreshing to hear this as a real question, rather than a statement delivered to buttress an ideological hatred of renewable energy. The answer is simple – there are generators already in place that are used to meet electricity demand during periods of low wind availability. The grid wasn’t built from a single energy technology. Fifty years ago, coal, gas, oil and hydro were used to supply power. Right now, these technologies have been joined by wind and solar, to reliably meet demand.

In the future, concentrated solar thermal, biomass and tidal energy might remove our reliance on fossil fuels altogether. But, the answer to the puzzle lies in discarding dogmatic barracking for individual fuel types, and being open to the advantages and disadvantages of all technologies on offer. Most importantly, it means demanding that people support their assertions with evidence. Another student seemed surprised by my display of the power output of wind energy, on Wednesday afternoon:

“Is this real? I thought wind turbines were useless!”

The general perception seems to be that wind power can only supply a tiny percentage of power to the energy market – a myth easily struck down by our analysis of the generation of wind farms during science week. At times, generation from wind farms is lower, but this is easily managed, and demand is easily met in states with a high installed capacity for wind farms.

When you strip away the layers of politics, emotion and rhetoric, wind turbines are simply a way of pushing electrons onto the grid. This conversion is quantifiable – we can meter the output of these machines, and watch it live, or chart it post-hoc. Recording and analysing changes in the world sits at the heart of science, and it’s a philosophy that ought to be hoisted above the swirling stream of mythology that seems to have latched onto the genuinely fascinating world of renewable energy.

Want to play with the data, graphics or pivot tables used in this article? Click here to download an Excel Spreadsheet (~12MB, make sure your computer can handle it!), or click here to play with a simplified version published using Google Sheets. If you notice any errors, please get in touch with me via twitter – @ArghJoshi

Ketan Joshi is a Research and Communications Officer at Infigen Energy. The views expressed in this article do not necessarily represent those of his employers.