New Tesla big battery at Lake Bonney wind farm delayed again

The second Tesla big battery planned for South Australia next to the 275MW Lake Bonney wind farm has suffered more delays and will not likely come into service until six months after the installation was completed.

The 25MW/52MWh battery being installed at Lake Bonney by listed renewable energy developer Infigen Energy is less than half the size of the first Tesla big battery, officially known as the Hornsdale Power Reserve, and located next to the Hornsdale wind farms operated by Neoen Australia.

The Lake Bonney battery to have come into service earlier this year, but Infigen said in May that while the “physical installation” of the $38 million battery was substantially complete (see image above), including the inverters and related balance of plant, connection issues were still being worked through.

It was thought then that the commissioning would be complete in the September quarter but that has now passed. The latest indication from Infigen Energy in recent statements, without further explanation, is for the connection to be complete by the end of calendar 2019.

Infigen will be keen for the battery to start operation. The battery – like its predecessor at Hornsdale – will tap into the frequency and ancillary services market, and will also be used to “firm” its supply contracts with commercial and industrial customers.

It will also mean it can continue to generate and store electricity during negative prices on the wholesale market.

On Saturday, both the Lake Bonney 1 and the Lake Bonney 2 wind farms (blue and green lines in graph below) switched off for more than six hours  from around 7am to 1pm when wholesale prices turned negative, presumably because they had no customers over the long weekend.

A similar shutdown of Lake Bonney 1 and 2 occcurred on Monday, also a public holiday, as prices went negative again.

The smaller Lake Bonney 3 wind farm (purple line in graph above), which has a long-term power purchase agreement, continued to generate because the price fo its output is guaranteed – although some newer PPAs also require wind or solar farms to turn off, as the Tallem Bend solar farm in South Australia has been on numerous occasions in recent months.

Lake Bonney will be the third big battery to join the grid in South Australia, after Hornsdale and Dalrymple North, with a smaller 10MW/10MWh battery due to be completed soon at the new Lincoln Gap wind farm near Port Augusta, and at least half a dozen major battery projects proposed at other large wind and solar farms in the states.