Neoen, arguably the most successful developer of battery storage in Australia and the owner of several landmark projects, has conceded that part of the grid connection process for one of its newest batteries has been delayed because of the complexities of having multiple equipment suppliers.
Neoen built the first big battery in Australia, and the biggest in world at the time, at Hornsdale in South Australia, and followed this up with the Victoria Big Battery near Geelong (which also held the title of the biggest), and is now building the giant 560 MW, 2240 MWh Collie battery, which will also – for a time – be the biggest in the country.
In the meantime, it has built and is building a number of other battery projects, including at Bulgana in Victoria, Capital in the ACT, Western Downs in Queensland, and Blyth in South Australia.
It’s the latter, the 238 MW, 477 MWh Blyth battery around 120 kms north of Adelaide, that has run into issues caused – says Neoen – by its decision to use separate suppliers for the battery components and power control systems and the inverters.
The Blyth battery is significant because it forms a key part of Neoen’s landmark contract to deliver “baseload renewables” to BHP’s giant Olympic Dam mine, along with the Goyder South wind farm.
That contract is still on track, and on schedule, Neoen says. But Blyth will also feature so-called “grid forming” inverters, as opposed to the more traditional “grid following” inverters, and it is this part of the battery project that has been causing problems.
Grid forming inverters are considered a key part of the transition to a wind and solar dominated grid because they can provide some of the key “grid services” such as synthetic inertia and system strength usually provided by spinning machines in coal, gas and hydro power plants.
Neoen has used a single provider – Tesla – for most of its big battery projects in Australia, such as Hornsdale, VBB, Bulgana, Collie and Western Downs, including for those using grid forming inverters.
However, for the Blyth battery it selected a consortium of Elecnor Australia and NHOA Energy to design and construct the battery. The battery has been delivered using batteries from Chinese giant CATL, and inverters from Spanish manufacturer Power-Electronics, while the Power-Plant Controller and BMS were provided by two different parties.
However, it has run into problems as it prepares for the 5.3.9 grid connection process for those inverters, which it says has caused delays and added costs.
“Compatibility issues with the advanced inverters and site controller and contract uncertainties have delayed the commencement of the 5.3.9 studies and connection application for GFM capability,” Neoen writes in a Knowledge Sharing report that it is obliged to submit as part of funding from the Australian Renewable Energy Agency.
The report does not portray a disaster of any sort, and Neoen insists that the BHP contract is on track, and that the battery will soon connect to the grid.
But the issues around the grid forming inverters are part of the key learning process for new technologies that ARENA funding is designed to support, and it does include important lessons for the industry. The big lesson in this case is that it is less good to have too many cooks in the battery broth.
“(The Blyth battery) is being built by multiple parties in a consortium,” the report says. “Within that consortium however, there are additional parties delivering discrete devices critical to the overall generating system.
“As the project has progressed through the preliminary engineering to convert (the battery) to GFM (grid following mode), it has become challenging to determine which aspects of technical requirements are the primary responsibility of certain devices as opposed to devices which are also part of the generating system namely the PPC and inverters.
“The complex nature of standard multi-party agreements for delivery of projects like a large-scale battery mean it becomes unclear to the point it is not possible to determine with certainty where within the multi-party arrangement technical requirements and responsibilities lie.
“The root cause of these issues stems from uncertainty relating to the overlapping technical requirements from each party to deliver GFM capability, compounded by the fact that the original agreements for the project were to deliver a GFL (grid following) BESS.”
It says these issues can be apparent in the operations of the battery, as well as the initial connections process.
Asked what it would do differently with the benefit of hindsight, Neoen says it would “more forcefully” engage the various parties – including the network operator – to make sure the issues were understood.
The GFM connection process is already devilishly complicated – particularly in retrofits as Neoen discovered at the VBB – but also with last minute changes as occurred with Blyth. (It was originally going to install only grid following inverters rather than grid forming, but this will change with the assistance of the ARENA funding).
“The challenges faced in clearly defining technical responsibilities among multiple consortium parties and their associated devices complicated decision making about replacing components due to impacts on project timelines and contractual obligations,” Neoen says.
“It is recommended to simplify the number of devices and parties involved in supplying the control system for the generating system as this would reduce the risks during upgrades and eased contract negotiations and management.”
And, that, it says, will also help to “lower the cost and improve the timeliness to deliver projects, which in turn should reduce the cost of electricity delivered to the end consumers.”
Blyth completed the mechanical construction of the battery late last year, ahead of schedule, but it is still working through the final stages of its hold point commissioning process and it is expected to start commercial operations soon.
Grid forming commissioning will commence at a later stage once the 5.3.9 submission has been made and is approved. The battery has been visibly active at high charge and discharge levels in recent days.
Note: This story has been updated to clarify the equipment suppliers, and to make clear that the problems lie within the grid forming inverter component, and that the BHP supply component and overall function of the battery has not been affected.
