Today’s news is full of stories on corporations, cities and other organisations that are investing in wind and solar. But many are only plans and projects – and the impact though worthy is often small. The term greenwashing has been used. But recently, the state of South Australia and Transport for London (TfL) have passed some significant milestones. By Jeremy Torr.

Adelaide, Australia. November 2020. Sunday October 11 saw an enormous step forward in the widespread use of renewable energy; the entire state of South Australia (SA)’s energy demand was met one hundred percent by solar panels alone.

“Never before has a jurisdiction the size of South Australia been completely run be solar power, with consumers’ rooftop solar systems contributing 77%,” said Australian Energy Market Operator (AEMO) CEO, Audrey Zibelman,

Thanks to mild temperatures and cloudless skies that day, the state’s 288,000 rooftop solar installations fed almost 1,000 megawatts (MW) back into the grid, with large-scale solar farms (like the Bungala solar power plant near Port Augusta) topping that up with an extra 300MW at the same time.

“This is truly a phenomenon in the global energy landscape,” added Zibelman. “The domination and successful integration of rooftop solar in South Australia foreshadows the rebuilding of jurisdictional power systems (across) Australia,” she added.

Rooftop solar is installed on over 30% of SA homes, with 2,500 systems installed every month at current rates.  To achieve this level of renewable power generation, AEMO has worked with existing transmission and distribution network service providers to ensure the power system remains secure and reliable.

“We are working hard to identify technical solutions to replace power system services, such as inertia, system strength and voltage control,” said Zibelman. The organisation’s aim is to replace the service-level provisions previously provided by conventional thermal (coal, gas) power generation in Australia, and to reach even higher penetrations for renewable generation.

“South Australia is experiencing a surge in rooftop solar installations. We are  forecasting an additional 36,000 new rooftop solar systems in the next 14 months, which will mean that SA’s grid will see zero demand - rooftop solar alone will be able to meet 100% demand,” Zibelman added.

The authorities are estimating that by 2040, more than 60% of coal-powered electrical generation will be replaced with grid-scale renewable energy, with rooftop solar and residential battery capacity also expected to double or triple.

SA Power Networks spokesperson Paul Roberts said that the state has an ‘exciting future’ with its rapidly expanding solar and renewable capability. But the change to renewables means a different usage pattern for consumers. They need to use air-con, dishwashers, pool pumps and hot water systems in the middle of the day, rather than when they get home from work – and investing in batteries to store power when the sun is shining. All these things could be helped by the introduction of different (lower) tarrifs for daytime use, said Roberts

Across the other side of the world, Transport for London (TfL) last month saw its power supplies pass the 15% renewably-sourced hurdle. “As one of the single biggest purchasers of energy in London, it is important that TfL leads the way on green energy,” said Lord Mayor Sadiq Khan. “This is a vital step towards my ambitions for TfL - and London - to be zero-carbon by 2030.”

TfL’s fleet of trains buses and other energy use departments suck up 1.6TWh every year, the same as 437,000 average homes. But by concentrating on specific sectors, TfL has managed to make all its staff, station and depot power requirements run purely on renewables..

“One hundred per cent of the electricity used to power London Underground officers station and depot power requirements is now supplied using renewable energy,” said Khan. The remaining electricity demand that is used to run the trains is powered by the standard grid mix of electricity. Moving to purely renewable power by 2030 is a bit ask, though. One study by British Business Energy estimated it would need 200 wind turbines or 5.6 million solar panels to completely cut out fossil fuel energy.

And while that is a decade away, SA has proved it can be done.

“We’re shaping a better energy future,”said Zibelman.