People, companies and governments around the world are seeking solutions to intermittent blackouts caused by ageing infrastructure and fragile supply chains.
Solar power, especially rooftop solar power, is emerging as a leading source of consistent and renewable energy — particularly when paired with the rapid innovation not just of battery technologies but also of methods to redistribute the electricity they store.
A combination of technological and social innovations could help pave the way to an energy system that, while still dependent on the weather, could prove more resilient to climate impacts, political and economic shocks, experts say.
“Each technology has its own special set of outages and stoppages,” says Stephen Turner, a senior business development manager at the clean tech company Zenobe, which focuses on building a circular economy for renewable energy storage. Concerns about intermittency — the fact that any given power source might go down, either periodically or in response to disruptive events — are often used to describe wind and solar power, but it’s far from being unique to renewables, Turner says.
Batteries installed alongside solar panels allow for excess energy from peak sunshine hours to be either redistributed via the grid or stored for later use. They have become much cheaper over the past decade, and are now affordable enough that it has become possible for the world’s sunniest cities to run on solar power 24 hours a day, according to the energy think-tank Ember.
The technology is popular in Puerto Rico, which has struggled with regular power outages since its electricity grid was severely damaged in a 2017 hurricane. Over the past decade, many residents have invested in solar panels for their homes to protect themselves both from the fragility of the central electricity grid as well as from the potential interruption in gas supply and associated spikes in prices, says Cathy Kunkel, an analyst for the Institute for Energy Economics and Financial Analysis.
As of this year, more than 10 per cent of the Caribbean island’s energy comes from rooftop solar panels, and the territory’s grid operator expects that rapid increase to continue.
Now, Puerto Rico hosts Latin America’s first operational virtual power plant. The programme draws on more than 2,000 batteries, owned by people across the island who have enrolled and own a solar-plus-storage system, to make up for power supply shortfalls by the central grid. The system allows individuals to be compensated for helping stabilise the island’s electricity system while still conserving energy for their own use.
Australia has also seen a shift towards renewable energy since 2022, when a combination of factors, including the volatility of oil and gas supplies following Russia’s full-scale invasion of Ukraine, contributed to an energy crisis. Today, roughly a third of Australian homes have rooftop panels. Starting in 2026, residents of three states will be eligible for free electricity for three hours a day as long as they have a smart meter installed.
About a third of Australian homes have solar rooftop panels © Brendon Thorne/Bloomberg
“What I think is going to play a pretty big role is the software systems and the automation of these different [energy] loads,” says Johanna Bowyer, IEEFA’s analyst for Australian electricity. For instance, the grid tends to be most stressed — and energy most expensive — in the early evening, when many people get home and start using their household appliances while the sun is going down.
“Say you plug in your electric vehicle when you get home,” she says. “When does [the vehicle] actually start charging? Does that happen right at peak demand? Or does that happen a few hours later?”
What I think is going to play a pretty big role is the software systems and the automation of these different [energy] loads
Johanna Bowyer, Institute for Energy Economics and Financial Analysis
Some of these innovations are large-scale, and make use of existing infrastructure, Turner at Zenobe says. For instance, in Queensland — another Australian state with a high percentage of renewable electricity use — a decommissioned gold mine has been repurposed to store power from nearby wind and solar farms by pumping water between two reservoirs and releasing power when energy prices are high. A similar project is being built in Europe’s deepest base metal mine, located in Finland.
“That’s sort of another way you can combat a lot of that intermittency,” Turner says — and it’s been garnering interest from owners of infrastructure that might otherwise decrease in value as the energy transition progresses. “Asset owners might, instead of decommissioning their gas plant, just turn it into a synchronous condenser,” another kind of system that can help hold large quantities of energy, Turner says.
A useful feature of wind and solar energy is that, while both are intermittent, they also complement one another, says Mark Jacobson, a professor of environmental engineering at Stanford. “There is a meteorological correlation between cold and wind, just like there is hot and sun,” he says. In many energy markets that have a strong preference for renewables, such as California and Australia, the bulk of energy supply during the night-time comes from a combination of wind energy and batteries charged by solar power.
This is the case in South Australia, says Bowyer, which uses more than 70 per cent renewable energy. There, rooftop solar power alone accounted for over 60 per cent of energy demand over peak sunshine hours throughout November, according to data provider Open Electricity, with most of the remainder made up by wind and large-scale solar power projects owned and operated by utility companies. During night-time hours, wind power covers about 80 per cent of demand, and solar-charged batteries provide another 5 per cent to 10 per cent. The majority of fossil fuel use occurred at night time.
“The goal is that the households can still do what they need and have that system firmed up enough that we’ve got these different energy sources that are quite diverse that we can call upon to fulfil demand whenever we need it,” Bowyer says. “It’s about having a flexible generation and supply side, and then getting as much flexibility in that demand side as we can.”
