“Just as common as solar-hybrids:” Most developers now including batteries in plans for wind

Over the last 18 months wind developers have started thinking about how they too can add a battery to upcoming projects, with most now looking at the issue.

Energy consultant Marija Petkovic says that every developer she knows is now looking at battery storage from the earliest stages of project development, but work still needs to be done to work out how these will best function in Australia’s rapidly changing energy market.

“They’re planning for it from the start, which is very different to what the case was a couple of years ago,” Petkovic, the founder of EnergySynapse, told the Wind Energy Forum in Melbourne last week. 

“I think we’ll see wind and best hybrids becoming just as common as solar-based hybrids.”

Developers are now looking at batteries because low prices are increasingly a challenge for wind farms all over the National Energy Market (NEM). 

Two such wind and battery hybrid projects – Baldon and Bungaban – were among 19 winners of the latest Capacity Investment Scheme generation tender, along with six solar-battery hybrids, a technology combination that has dominated recent federal and state tenders.

Petkovic says almost every single wind farm in the NEM is earning a dispatch weighted average price that is significantly lower than the average spot price.

If wind projects can do a little of what utility-scale solar has so successfully done over the last few years and time-shift low value electricity to a more profitable time of the day, that will drag up the price “capture” a site is able to achieve. 

Battery warranty stretch

Already battery manufacturers are moving to better enable both solar and wind hybrids, with a shift towards 30-year warranties for large-scale batteries.

The problem, particularly for wind projects where generation isn’t as predictable as solar, is that no two battery warranties will be the same, with different conditions on how they can be operated, such as how long a battery can be kept at maximum storage.

That means that wind farms also can’t be so big that batteries are kept full for long periods. 

Petkovic is “seeing some movement” by battery manufacturers to support big generation projects with better terms and longer warranties past the current 20 years. 

“Given that the wind is expected to have a longer life, your financial model would have to take into account that you’re going to be doing some replacements of inverters and the like at the battery or replacing cells,” Petkovic says.

Testing underway

Turbine manufacturer Goldwind is already building and testing a system that combines wind with storage and control systems adapted for this new hybrid.

Fellow Chinese turbine maker Envision has built its own large-scale “living laboratory” in Chi Feng in China, to get a better understanding of what true, AC-coupled wind and battery energy storage systems (BESS) can offer a modern-day grid.

As Renew Economy reported last week, that company believes a wind farm with an appropriately-sized battery can not only replace the generation of coal power but replicate its system performance.  

Petkovic says battery sizing is “tricky” because the battery will cannibalise some of the revenue from a wind farm. 

“But in a DC coupled variation, the battery is actually going to be distributed across the site, located at individual turbines. This has implications on where your revenue cannibalisation occurs,” she says.

“When we talk about revenue cannibalisation, what we mean there is the competition for export from the wind farm in the battery.

“In an AC-coupled scenario [with a battery at one centralised location but operating as a separate asset sharing a connection point], this is happening at your point of connection, but in a DC coupled configuration, it’s actually also happening at that individual turbine level as well. 

“When you’re modeling DC-coupled hybrids, you do need to take that into account, those turbine level power limits.”

Bigger is not always better either. 

The best times for wind farms to send power to the grid tend to be evening and night time, so investing in a powerful battery with lots of storage to capture some of that – just when households are using the most electricity of the day – will result in a lot of capacity that can’t be well used. 

“There will always be some cannibalisation of revenue in a hybrid context,” Petkovic says. 

“But the thing is, in the hybrid configuration, you’ve got the benefits of not having to find new land [for a battery if you’re planning one in the area], you can utilise your existing site, or at the very least, you can avoid that additional cost of a whole new connection for a separate asset in the hybrid. You’re able to monetise your curtailed energy, which you wouldn’t be able to do standalone either.”

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