Another big year for BESS 12 min read
Utility-scale batteries reached new heights in 2024, achieving several industry firsts. Milestones include the first project-financed virtual offtake agreement and long-term energy service agreement (LTESA), coupled with inventive approaches to revenue stack structuring. As investor interest intensifies, the future of battery storage looks promising.
This latest Insight on the Australian big battery market delves into the recent trends, the potential opportunities and hurdles for this rapidly evolving industry.
Key takeaways
- Project financing of battery energy storage system (BESS) projects is on the rise, with an increasingly sophisticated market, a widening pool of sponsors and diverse range of investment structures.
- Virtual offtake agreements are dominating the offtake market, giving developers greater flexibility in their revenue stack and opportunities for equity upside through market arbitrage.
- Interest in the Capacity Investment Scheme and LTESAs is increasing and contributing to projects reaching financial close.
- Equity investors continue to be attracted to standalone and co-located BESS projects, as well as investment in the hardware and software of a battery.
What we are seeing in the market
A growing number of battery projects achieved financial close across the past year and project finance has continued to be the dominant approach. We have seen significant greenfield and operational battery projects financed on a standalone basis and as part of hybrid projects, as well as portfolio-based financings.
Key examples of this trend are the renewables portfolio financings for Global Power Generation, FRV and Neoen, all of which included battery projects as part of the technology mix. Akaysha Energy's standalone financing of its Orana Battery Energy Storage System marked a financing for the largest four-hour BESS in Australia's National Energy Market (NEM), and one of the largest in the world.
The continued support in the project finance market for battery storage projects has been driven by a range of factors, including:
- a widening pool of sponsors—and, in some cases, extremely strong sponsors—who are investing in the technology;
- a diverse range of investment structures and rationales, which have seen developers and sponsors raise debt financing for batteries on a standalone and portfolio basis, or as part of co-located or hybrid projects. In some cases, this has been motivated by a business pivot or expansion in response to an increasing need to couple projects with intermittent generation sources with a firming energy source or, more generally, net zero and decarbonisation objectives; and
- increasing sophistication and experience of developers, contractors and other stakeholders in relation to procurement and contracting strategy, trading strategy, management of interface and gap risk in the context of split contracting, and innovation in revenue structures.
These trends have been accompanied by—and, in some ways, conducive to—an expanding range of financiers (including mainstream commercial banks, government lenders and other non-bank lenders) participating in financings for battery projects; a greater understanding from lenders of technology and degradation risk; and a greater market acceptance of split contracting structures and non-traditional revenue structures as bankable.
Throughout 2024 we observed a marked increase in the development and adoption of virtual offtake agreements as a preferred offtake structure. Notable examples are Neoen's Western Downs BESS and Victorian Big Battery, and, as mentioned earlier, Akaysha's Orana BESS.
A virtual offtake agreement decouples the financial offtake from the physical project. The project company may therefore choose not to follow the instructions of the offtaker and instead operate the BESS according to its own internal trading strategy, but it must still settle the financial swap on pre-agreed terms, regardless of battery capacity and how much the battery is charged or discharged.
From the project company's perspective, unlike a traditional physical toll, it retains control of the physical battery. This increases the opportunities for equity upside through trading arbitrage. The structure also facilitates greater flexibility for a single project to procure offtake agreements with multiple offtakers. It may also be compatible with hybrid or co-located projects in need of multiple offtakers for different components of the project.
Virtual offtakes are not, however, for everyone. Both the owner and the offtaker need sophisticated trading teams to allow them to make the most of the virtual arrangements and to reduce the risk of making losses. Similarly, developers who want to sell out of a project prior to financial close may want to consider whether a virtual offtake agreement could limit the potential buyer pool to those that have the technical capability to trade the asset.
In considering this type of structure from a financing perspective, lenders will be focused on mitigating the potential downside exposure in circumstances where physical trading by the project company underperforms against the virtual nominations, eroding actual base case revenue against revenue assumptions against which debt is sized.
Providing lenders with appropriate oversight and protections (including, if required, agreed trading protocols), while providing sufficient room for equity to seek upside opportunities, will be the key to building broader market acceptance of the bankability of non-traditional revenue structures such as virtual offtake agreements.
Last year saw the Federal Government launch the first five tenders in its Capacity Investment Scheme, which wrapped in a tender for the NSW Government's LTESAs.
Each tender round has been oversubscribed, indicating a strong appetite from project developers to secure a government underwriting contract such as a Capacity Investment Scheme Agreement (CISA) or an LTESA.
While these underwriting contracts have typically been viewed by project financiers as welcome enhancements, they have traditionally been seen as a 'nice-to-have' feature, with the primary focus of lenders being on whether the project has the benefit of a traditional tolling or offtake agreement. At most, we saw sponsors and borrowers proposing to recognise CISAs and LTESAs acting as a floor against any potential market risk (either due to the residual life of the BESS past the offtake tenor or for partially contracted assets).
More recently, we are seeing lenders develop a greater understanding of how such agreements can underpin forecast project cashflows in a way that enables higher weighting to be placed on them as a certain and bankable revenue line in the base case financial model. This approach is often supported by tailored protections that are agreed in the debt documents, such as:
- undertakings around how the project activates and manages its rights to receive support payments;
- information undertakings, to provide lenders with appropriate visibility over the operation of the underwriting agreement during the facility term; and
- cash reserving requirements, to facilitate the project maximising the benefit of underwriting agreements, while providing for a buffer should there be a need to meet any payment obligations back to the counterparty (eg reconciliation payments or rebates).
As more government underwriting agreements are awarded under the LTESA and CISA schemes, there will be an increasing number of projects in the market where such agreements are a feature of the revenue profile. We expect that market acceptance of this approach will continue to broaden over time.
Split contracting has established itself as the market standard for BESS projects, with sponsors and financiers becoming significantly more comfortable with managing and banking the interface risks between battery supply and balance of plant (BOP) scope.
Commissioning, handover, defects, security, liability caps and liquidated damages coverage continue to be key areas of focus in negotiations, gaps analysis and bankability assessments. However, the issues, and the related mitigation strategies and contingencies, are now well understood.
As the BESS split contracting structure has matured, we have also begun to see sponsors with a portfolio of upcoming BESS and other renewables projects seek to partner informally with preferred battery suppliers and/or BOP contractors across that pipeline—the goal being to expedite procurement timeframes, secure production slots and standardise terms across their portfolio.
With BESS projects increasingly being co-developed with related solar/wind projects (either greenfield or expansions), we also expect to see an increase in a common BOP contractor delivering both the battery and solar/wind BOP scope. At this stage, the BOP scope usually remains ringfenced between assets (eg there is a BESS BOP contract and a solar BOP contract). However, we expect to see sponsors push towards a single hybrid project BOP contract covering both assets, to seek to streamline contracting terms and construction programs on hybrid projects.
In order to ensure that the structure is bankable, project financiers require a rigorous gaps analysis process underpinning the contract negotiations, along with confidence in the capability and experience of the contractors themselves. The need for a robust gaps analysis does mean more substantial engagement with financiers, and sponsors and developers have had to factor this into the overall transaction timetable. However, the continued rise in standard terms contracts from certain contractors in the market may facilitate efficiencies in the due diligence process, especially on portfolio-based financings.
Investors continue to be attracted to BESS assets. Unsurprisingly, the reasons for their increasing investment appeal are similar to why we are seeing more and more BESS projects reach financial close.
These factors enable BESS owners to diversify and maximise revenue output from their renewable energy portfolios. Coupled with favourable investment characteristics for BESS assets, such as lower capex costs and shorter development timelines (particularly when compared with other renewable asset types), we expect to see investment appetite for BESS assets continue to grow.
In the Australian M&A market, this investor appetite has manifested primarily in the form of co-location 'add-ons'—where vendors looking to sell a solar or wind project have added a BESS development opportunity to the project. If the BESS can be developed on the project's existing land footprint, the 'add-on' process is relatively simple (other than for the connection process, which continues to cause headaches for developers), and the project up for sale can be rebranded as a co-located wind/solar and BESS project, unlocking for the buyer the various new revenue streams. For the vendor, those additional revenue streams mean a higher purchase price.
What's on the horizon
Recognition of sub-investment grade offtakers?
The offtaker's credit quality will continue to be a focus for lenders when assessing BESS projects. However, as a greater range of offtakers enter the market, we can expect more frequent proposals for financiers to consider counterparties that may not have the credit ratings that would typically be required for a bankable project.
We are seeing this area incrementally develop. This is particularly so in renewables portfolio financings, where certain sub-investment grade offtakers may be recognised and given greater weighting (and, in some cases, equivalent to an investment grade offtaker) as part of debt sizing cashflows, subject to appropriate percentage caps and other criteria being met.
Opportunities for fully merchant BESS projects
A further example of the evolving market for BESS financings may be found in the recent Amp Energy project financing of a fully merchant BESS project by commercial bank lenders and Export Development Canada. While we have certainly seen project financings for BESS projects with merchant exposure, those projects have typically included at least some contracted revenue component (whether through a tolling agreement, virtual power purchase agreement, LTESA or revenue risk-sharing agreement).
This makes the Amp transaction an interesting market development. Depending on the project and the sponsor, the debt model on the Amp transaction may not be feasible for all sponsors and developers, given that a fully merchant BESS compared with a contracted BESS would necessarily mean more conservative debt sizing, at least in the short term. However, for certain sponsors with strong equity backing, where a high percentage of equity is available to be contributed to individual projects, and where there are challenges or other commercial reasons for not procuring an offtake, a fully merchant-based project financing may still be attractive.
Whether this means we will see a growing number of merchant BESS project financings is unclear. The Australian Energy Market Operator (AEMO) forecasts energy storage capacity in the NEM will increase from approximately 2GW at the end of 2024 to nearly 7GW by the end of 2025.1 As more BESS projects come online over time, there may be fewer arbitrage and other similar revenue opportunities.
At least in the short term, we expect this may lead to certain sponsors and developers more closely exploring opportunities to raise debt against BESS projects that are fully merchant or that have substantial merchant exposure.
Investment in BESS platforms and core components
A growing trend is the investment in BESS-specific investment platforms. While only a limited number have come to market in Australia so far (including the recent ZEBRE BESS platform announced by ZEN Energy and HDRE), we have worked with a number of investors who are looking at opportunities in this space. Investors are drawn to the benefits of BESS projects described above and the potential to accelerate the growth of those benefits when they are aggregated on a portfolio basis.
We have also seen increased investment interest in core BESS components, including:
- the hardware—as rival technologies, focused on cost efficiency and safety, are emerging to challenge lithium-based batteries; and
- the software—focusing in particular on storage and discharge optimisation.
While the current focus from investors in these core BESS components appears to be on systems designed for the residential and commercial and industrial markets, the ambition for a number of these technologies is to scale up to the utility-scale BESS market.
Commencement of the GO Scheme
The Guarantee of Origin Scheme (the GO Scheme) is set to commence in 2025, bringing with it new tradeable certificates in the form of Renewable Energy Guarantee of Origin (REGO) certificates. Unlike large-scale generation certificates, REGOs will be able to be created by energy storage systems (such as batteries) where there is a 'direct supply relationship' with an eligible renewable energy facility.
In addition, REGOs will be time-stamped, meaning they will record the hour of the day in which they were generated. This will allow temporal matching of electricity generation and consumption, and will likely drive a price differentiation between eg REGO certificates generated at 1pm when there is excess solar generation and 1am when renewable energy supply is scarce.
The introduction of REGO certificates presents an interesting opportunity, and a potential new revenue source, for BESS projects.
More information on the GO Scheme can be found in our previous Insight.
Revenue implications from AEMO's market interventions
Under the National Electricity Rules, AEMO has powers to issue mandatory 'directions' to registered participants in the NEM in relation to the operation of their facilities. This is not uncommon, and is primarily used by the market operator to manage periods of volatility in the market and maintain the reliability standard. Participants are subsequently reimbursed for their compliance via a well-established compensation framework administered by AEMO.
AEMO has indicated that it intends to use its directions power on battery operators to address the increasingly commonplace minimum system load issues— eg by directing an operator to fully discharge batteries early in the morning and to hold the batteries at minimum charge during the morning, with the direction lifted in the early afternoon.
However, there are growing concerns that this directions compensation model is not fit for purpose for standalone batteries and other energy storage technologies. The financial model for a standalone BESS is particularly reliant on taking advantage of exactly these periods of financial volatility in the market, and AEMO's directions compensation framework may not be appropriate in providing adequate financial redress for the opportunity cost that is lost by virtue of being required to comply with an AEMO direction.
Following the AEMC's 'Review into electricity compensation frameworks', the final report for which was published in December 2024 and can be found here, we expect there to be continued discussions on this issue, to ensure that BESS operators are fairly compensated for AEMO's market interventions.
Vanadium flow as an emerging alternative to lithium-ion?
As the BESS market expands, we expect to see competing technologies emerge as alternatives to lithium-ion batteries. The WA Government recently announced $150 million of funding to develop a 50MW / 500MWh vanadium flow battery (VFB) in Kalgoorlie, which would be Australia's largest VFB. While VFBs have been mooted for a number of years as a potential utility-scale alternative to lithium-ion batteries, the first (and largest) 'commercial' VFB in Australia (a 2MW / 8MWh battery) was only commissioned in mid-2023, as part of the Spencer Energy Project.
The key roadblocks to the widespread adoption of utility-scale VFBs seem to be higher upfront costs compared with lithium-ion batteries (vanadium is heavily used in steel refining, which creates price and supply chain volatility), and lower roundtrip efficiency of around 70–85% (compared with 90–95% for lithium-ion batteries).
Despite this, VFBs seemingly provide a number of commercial benefits compared with lithium-ion batteries. In particular, VFBs offer longer storage duration (between 8–12 hours), and the theoretical ability to discharge completely and for an unlimited number of times without significant degradation (providing a much longer and consistent asset life). Further, VFBs are said to be safer (and fire resistant), and storage capacity can be easily increased by adding more electrolyte. At scale and over time, these benefits could help drive a significantly lower LCOE. The WA Government's funding may be the catalyst to cut upfront costs and kickstart VFBs as a leading alternative to lithium-ion batteries.
The continuing evolution
As we look ahead, it is clear that 2025 promises to be another exciting year for the BESS sector. We expect to see more diverse, and growing, opportunities for battery projects, including across construction contracting, revenue structures, project and portfolio-based financing, and M&A.
If you would like to hear more about what we're seeing in the market, please contact any of the team members below.
Footnotes
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[1] AEMO | Generation information (NEM Generation Information).