Which energy storage technology is going to power Australia’s future?

Recent events in Australia indicate a growing appetite for renewable energy and energy storage in the energy sector. Pumped hydro, thermal energy storage, hydrogen—which form of storage will reign supreme Down Under?

New regulations and a growing share of renewables are changing the way the electricity market operates in Australia, opening up a playground for new energy storage technologies that could deliver a cleaner energy grid, said speakers at a conference in Sydney earlier this month.

New South Wales Parliamentary Secretary for Energy, Ben Franklin, told the audience: “Put simply, [people] want reliable, affordable power, and they expect action on climate change…We know that climate risk is impacting the design and future of electricity systems all over the world, with or without policy measures.”

ENERGY

As the cost of energy storage solutions like batteries slides down the cost curve, Australia has a chance to lead globally in the creation of large-scale electricity grids that can balance a high volume of renewable energy, Franklin said at the 2019 Australian Energy Storage Conference and Exhibition.

The share of renewable in Australia’s energy mix has leapt from about 8.5 per cent to about 21 per cent since the early 2000s. In 2018, hydro power was 7.5 per cent of total power generation, with wind close behind at 7.1 per cent and small-scale solar power at 4.2 per cent, according to the Clean Energy Council.

But the intermittency of wind or solar energy—that is, power generation that is inconstant and depends on the weather—is proving to be a stumbling block in scaling up clean energy.

Energy storage technologies like batteries can make energy from irregular sources available for a larger part of the day. Batteries can charge up during the middle of the day, when the sun is out; and then discharge in the early evening, when solar panels are no longer generating but household demand for energy is at a peak. This is known as time-shifting in the energy industry.

With storage becoming cheaper, a combined renewable-storage source of generation is a more attractive option to replace a coal or gas plant. As the newly-elected federal member of Parliament for Warringah, Zali Steggall, told attendees at the conference: “With battery costs predicted to drop 70 per cent by 2025, I think the wind—pardon the pun—is behind us”.

More room for storage
But energy storage can be used to provide services beyond ‘time-shifting’ renewables. One example that had tongues wagging was the upcoming introduction of five-minute settlement to the wholesale electricity market. Compared to the existing system where the price of electricity is settled every half hour, the new system is more responsive to demand, which would lead to lower prices.

Growing government support for virtual power plants (VPPs) could also create more demand for energy storage solutions. The New South Wales government has announced it would install smart batteries on government buildings to boost energy security by providing up to 13MW of through a virtual power plant.”

A VPP is a network of batteries and power generating assets such as solar panels, physically spread out but centrally controlled. These networked batteries can charge or discharge at the most opportune time for the grid, collectively acting like a large power plant, without the large emissions footprint of the real deal.

Terry Daly, director of Energy Programs at New South Wales’ Department of Planning and Environment, told delegates at the conference that VPPs have a role to play in the state government’s Emerging Energy Program, with several projects yet to be announced.

These are just two examples of the paradigm shift underway in the Australian energy landscape that are enabling a range of commercial opportunities for energy storage, and inventors and investors are rushing to bring out new products to take advantage.

A new iteration of the classic lithium-ion battery is the focus of many. Rob Fitzpatrick, chief executive officer of Gelion presented s zinc bromide gel battery, developed in partnership with the University of Sydney, that is as flexible in application as rechargeable lithium-ion batteries but significantly more durable, safer, and doesn’t rely on the troubled lithium market for production inputs.

Thermal energy storage, which maintains a desired temperature without electricity inputs, is an attractive alternative for commercial and industrial energy users. Adam Valmoro, regional director of Viking Cold, explained how arrays of phase-change materials—which for instance shift between solid and liquid states and are excellent thermal regulators—can produce power savings and reduce the operating costs of refrigeration for food producers and warehouses.

Meanwhile, 1414 Degrees has developed a proprietary thermal energy storage solution that exploits silicon’s latent capacity to withstand extremely high temperatures. Using molten silicon, the company’s solution can output both heat and electricity.Its first installation at a wastewater treatment plant is powered by biogas, said chief operating officer Dr Jordan Parham.

But energy storage technologies such as batteries and thermal storage systems can’t provide a solution beyond a certain timeframe. That requires longer-duration approaches like pumped hydro: dams which pull water uphill when energy is cheap and releases it through turbines when demand increases.

The massive Snowy Hydro 2.0, a government-supported Australian pumped hydro project due in 2025, should add 2000MW of generation (roughly equivalent to a new coal plant) with a week’s storage capacity—enough to cover critical breakdowns in existing infrastructure.

For really long-term storage, it’s difficult to go past hydrogen, but hydrogen safety remains a concern.

While some of the technologies on display at AES 2019 will no doubt fall by the wayside, many speakers reinforced the point that decarbonisation can only be achieved through a mix of approaches rather than any single option. As MP Steggall reminded the audience: “Renewable power must be delivered reliably across the grid. Many technologies are needed, but the most important—as you would all agree, being here today—is storage.”

Source: eco-business