The energy landscape is churning, with new answers to the same old problem coming every day. The wee issue of intermittency in renewable generation isn’t going to go away and utility-scale batteries have popped up as potential policemen of grid stability. Visitors to this year’s Australian Energy Storage Conference and Exhibition noticed much of the talk was about units the size of shipping containers, whereas last year the buzz was about residential storage solutions.
The Finkel Review underlined the role utility-scale storage might play but the technology is relatively new. Some experts say it will be suitable for various services including frequency control, but they stipulate that it can’t provide inertia. Whatever the case, the $7 billion pipeline of solar and wind projects to be built this year and next will ensure large-scale storage is about to become much more common.
Finding a solution that’s fit for purpose isn’t straight-forward, however, and mistakes can be expensive. Customers must know what they want a battery to do, what technology they need and what is fair pricing for maximum benefit. Bargain-hunters shopping for an energy target can get it wrong.
Lithium batteries are not all the same, says Ike Hong, vice-president of the power solution division of Korean manufacturer Kokam. If some customers see a purchase as fairly straightforward, it isn’t. “They need to understand what service you’re going to use,” Hong says.
For example, a system that’s intended to cycle once a month will be expected to manage 120 cycles over 10 years. But if the owner starts pushing this low-cycle solution and expects one cycle a day out of it, he should have thought about purchasing a battery that could take a minimum 5,000 cycles, Hong says. “Even if your requirement is 3,000 cycles you can’t just buy a 3,000-cycle-life battery,” Hong says. “That’s dangerous. What if it doesn’t work in year nine or year eight? You need to have redundancy – or extra capacity.”
Know what you want
The ratio of power to energy, known as the C rate, is a very important consideration when designing the best battery solution. Hong gives the example of a system with a 0.5 C rate, where a 500kW battery provides 1MWh of energy. If the owner decides he wants to push the system beyond its C rating, however, it can’t be done. “But there will be a battery that performs to a higher C rate, with a little bit higher pricing.” The best solutions may not appeal to buyers who are inflexible about cost.
Hong says Kokam has expressed interest in further Australian projects but reminds EcoGeneration it has installed 42MW in the country to date. The maker has “200MW of experience” around the world and enough big data, he says, to offer genuine solutions and to know when to walk away from unrealistic briefs.
Which brings us to the uncomfortable question: Do customers know what they’re looking for?
“Typically, they know 50%,” Hong says. What usually ensues is a conversation about similar projects undertaken by Kokam around the world and then an invitation to get involved in the research. It may take extra effort of the customer’s part, but in the long term it’s worth it when they come back and say, ‘Hey, I now understand what you’re talking about.’ “When they understand, I know that now we’re talking.”
Initial inquiries that focus on price will only lead to Hong having to explain that “hundreds of different factors” must be considered before he can provide an estimate.
The right brief
In a market where the transition to renewables is accelerating and batteries are an obvious solution to some of the teething problems that brings, a rush to buy and build large-scale storage could lead some into trouble. “The biggest mistake battery companies are making today is … marketing themselves on [competitive] pricing,” Hong says.
The issue isn’t so much about bringing down pricing – “that’s good for everybody” – but quoting pricing off the cuff can be dangerous. A customer who has heard Elon Musk quote $250/kWh and expects the rate to apply to a 10,000-cycle battery with 4 C-rate power will be disappointed, Hong says. “You’re never going to find it anywhere on Earth!”
Cheap solutions that fail in the field will cause suffering for the whole industry. Enough is known about utility-scale storage for that not to happen, he says. Some systems have been running for up to six years, with no problems.
One such project is Kokam’s installation for Korean utility KEPCO. It was a success, Hong says, because in the first year different technologies were tested and delegates were sent around the world to see what was working in other regions. Only then did KEPCO define technical specifications and release a tender.
“They knew exactly what they wanted,” Hong says. “They didn’t want a mistake because pricing was a driver bringing bad quality product.”