✅ Roughly speaking
- ⚡ Compared to the solar power generation business, the grid battery storage business Connection review, market operations, and stakeholder coordination It is believed that the specific gravity of is very large.
- 🏗️ EPC operators have: Not from the basic design stage, but from the connection consideration stage It seems preferable to have them involved.
- 📈 Aggregators are not just outsourced; Business partners who influence equipment configuration and monetization assumptions We believe that it should be taken as.
- 🧭 Because so many players are involved, PMO (general management function) It seems important to clarify the division of responsibilities and process control by setting the following:
✅ Audio summary of this post here
Introduction
This time, Practical rules to avoid failure in the grid battery business We will explain.
Recently, I feel that an increasing number of companies are considering entering the grid battery business as their next revenue stream, taking advantage of the land acquisition and development experience they have gained in the solar power generation business.
In fact, it was held on September 24, 2025 Agency for Natural Resources and Energy's Next Generation Power System Working Group The main issue is the rapid grid connection of grid storage batteries.
It also drew on the materials of the meeting Passion Power explanation article The figures are summarized as follows: as of the end of June 2025, the capacity for connection consideration applications reached approximately 143 million kW, and the capacity for contract applications reached approximately 29 million kW.
SOLAR JOURNAL coverage According to the report, the number of applications for connection consideration for fiscal year 2024 was 9,544, an increase of approximately six times compared to the previous fiscal year.
However, you need to be careful here.
While the grid battery business is similar to the solar business in some ways, the way the business is organized is quite different It is considered that.
If we overlook this difference and proceed with "the same feeling as sunlight," it is likely that the cost of backtracking will be high.
Therefore, in this article, I will explain from the perspective that I feel strongly about in the field of legal and business support Three golden rules to follow when entering the market I would like to try to organize the.
Why it's dangerous to have the same sense as the solar business
Solar power generation projects are often assembled in a relatively linear manner, with land being secured, licenses being obtained, construction and sales beginning, but the structure of grid storage batteries is very different.
Specifically, The connection consideration is easy to directly connect to business profitability , that the centre of monetisation is in market operations , The increasing number of involved players complicates the division of responsibilities We believe that these three points are the essential differences from the solar power business.
Below, we will organize the practical rules in order to address these three structural differences.
Iron Rule 1 – Involve EPC operators from the "connection consideration" stage
Difference from sunlight. Connection considerations affect business profitability
In terms of grid connection, you can apply to a general transmission and distribution company or a power distribution company to consider connection, and based on the technical considerations, you will be able to determine whether the connection is possible and the construction cost contribution ( Explanation of the Agency for Natural Resources and Energy's system connections See).
Connection considerations are also necessary in the solar power generation business, but the weight of grid storage batteries varies.
Without a response to the connection review, construction costs and connection conditions are difficult to predict, and the structure is difficult to make the business profitable.
In fact, the aforementioned SOLAR JOURNAL coverage As stated above, the number of applications for connection consideration for fiscal year 2024 has reached 9,544, and there is a noticeable trend of applications being submitted for consideration at multiple locations simultaneously.
In other words, in the battery storage business, Connection considerations are not just an entry procedure, but an important initial action that determines income and expenditure assumptions It is considered easy to become.
Why early involvement of EPC operators is needed
In the renewable energy business, EPC (Engineering, Procurement, Construction). Design, Procurement, Construction) It is common to position the operator as the person who will carry out the design, procurement, and construction, but in the case of storage batteries for systems, It is desirable to involve them from the connection consideration stage I think so.
There are three main reasons for this.
- To be able to get a technical perspective into the process of exchanging information with general power transmission and distribution companies and organizing application materials early
- Reduces inconsistencies between initial layout assumptions and the actual design stage, and is easy to prevent rework such as rethinking connections and rearranging
- When selecting manufacturers and equipment configurations, it is easy to incorporate aspects such as construction, maintainability, delivery time, and implementation performance early on, rather than just price
In particular, it seems to be of great significance to carry out on-site inspections together with EPC operators as soon as possible.
Ground conditions, delivery lines, securing construction yards, and ease of handling neighbors are all easily linked to the construction period and costs if you notice them later.
Common Failures
To the extent that the author has seen and heard, After identifying the land and connectivity possibilities, we consulted with the EPC operator, who told us that the planned layout lacked construction space and delivery routes, necessitating a review of the equipment configuration and a re-application There is a case where.
In these cases, it is not uncommon to incur additional costs of tens of millions of yen and schedule delays of several months.
From a legal perspective, this type of backtracking is likely to spark contract changes, delivery liability, and damages, as well as additional costs.
Iron Rule 2 – Choose your aggregator first, not just "just before luck"
Difference from sunlight. The center of monetization is "market operations"
In the solar power generation business, the central theme is likely to be how to sell the electricity generated, while in the storage battery system, How to control charge and discharge, which markets, and when to convert them into value becomes the core of businessability.
Commentary by the Agency for Natural Resources and Energy According to the study, aggregators are positioned as operators who bring together demanders and distributed energy resources, and are responsible for balancing electricity supply and demand and market transactions.
Also, VPP (Virtual Power Plant. Virtual Power Plant)・DR (Demand Response). Demand response) In the, the role of aggregators and the like is shown to be to provide integrated control of energy resources and provide services such as coordination power, imbalance avoidance, and output suppression avoidance.
Although grid storage batteries do not necessarily assume only the resources of the consumer, the practical sense is that Instead of "if we build the equipment, it's over," we need to think about "deciding on the equipment based on operational assumptions." It is expected that this will be the case.
Why should we select at an early stage
Aggregators are not just "contractors for operations after completion."
Each aggregator has its own operating logic, track record in participating markets, and compatible storage batteries and PCS (Power Conditioning System). Power Conditioner)・EMS (Energy Management System). energy management systems) can be combined differently Because.
Therefore, if the equipment specifications are solidified first, they may not match the requirements of the aggregator you want later, narrowing your revenue opportunities and consignment options.
At least early in entry, it makes sense to interact with multiple aggregators to narrow down early on who fits your investment policy, expected holding period, risk tolerance, and exit strategy.
"Choosing" here does not mean rushing to make a contract, Find business partners who can share your equipment design assumptions first That's what I mean.
Comparison and selection points
When comparing aggregators, it seems useful to at least check the following points of view:
- JEPX (Japan Electric Power Exchange) Japan Wholesale Power Exchange) has a track record of participating in which markets, such as spot markets, capacity markets, and supply-demand adjustment markets
- What is the basic structure of revenue allocation, whether revenue-sharing or fixed-remuneration
- Are there any restrictions on the battery manufacturers and PCS/EMS combinations that can be supported
- Check for compatibility issues with control signal communication specifications and API integration
- What is the size and region of the project that has been used in operation
Common Failures
A common mistake is accepting the manufacturer's proposal first, solidifying the equipment specifications, and then consulting with the company to outsource the operation Control requirements and communication specifications do not meet, resulting in a large limitation of aggregator candidates It is that.
As far as I know, if these inconsistencies were noticed later, it would require the introduction of additional EMSs or firmware changes to the PCS, leading to additional investments of millions to tens of millions of yen, and in some cases, the luck period was pushed back by more than six months.
This is a technical issue as well as a fundamental issue in business schemes.
Iron Rule 3 – Establish a PMO, unify the division of responsibilities and processes
Difference from sunlight. Increased involvement of players and more complex division of responsibilities
In the development of grid storage batteries, there are various types of storage batteries available from business entities, EPC operators, storage battery manufacturers, PCS manufacturers, EMS operators, aggregators, and SIer (System Integrator. system building operators), construction companies, and many other players are involved.
There are several parties involved in the solar power generation business, but in the storage battery system, Technical specification alignment, control signal coordination, scope of responsibility for commissioning, responsibility for licensing and notification, initial operation in the event of a problem In this regard, it seems likely that the location of responsibility will become much more ambiguous.
Why we need PMO
PMO (Project Management Office). General Control) is a mechanism to address this complexity.
In a project involving a large number of players, even if individual contracts are carefully crafted, it is difficult to fully factor in everything that happens on the ground in advance.
In practice, it is not uncommon for issues to shift mid-specification, for it to become unclear who will submit the notification, or for initial action to be delayed when a malfunction occurs.
The expected role of a PMO is at least four things:
- Managing the entire process and setting milestones
- Documentation of the division of labour and division of responsibilities for each of the parties concerned
- Centralized management of issues and pending matters and regular inventory
- Consolidation of the liaison office in the event of trouble and clarification of the initial operating rules
In that sense, the PMO is more than just a secretariat; An umbrella function that supports project decision-making and promotion It seems better to understand this.
If there are not enough experienced employees within the company, it may be effective to appoint an external company with a track record of battery storage projects as a PMO.
Recently, there have been some operators, such as aggregators, SIers, and battery storage manufacturers, that can provide multiple functions in a relatively integrated manner.
We believe that the option of reducing the grey area of the division of responsibility to a certain extent by partnering with such parties also deserves full consideration.
Common Failures
The author's experience in the legal support field is that when a malfunction in the control system is discovered during commissioning or just before the interconnection, The response stalled for several weeks as it was not possible to immediately decide whether the battery manufacturer, SIer, EPC operator, or aggregator was primarily responsible There is a case where.
Such a condition undermines the credibility of the project itself, even before contractual liability theory.
The impact goes beyond financial damage, as failure to meet the scheduled interconnection date could even put the company at risk of losing its grid connection order.
Summary
The important thing to avoid failure in the grid battery business is not to fill in the individual points later, Don't get the first design idea wrong I think.
If I were to give you my order, the first three things you should check are:
- Before moving forward with land or projects, consider the connection and adjust the construction conditions from the perspective of the EPC operator
- Before finalizing equipment specifications, determine compatibility with the aggregator
- Before finalizing individual contracts, a PMO function will be established to oversee the entire project
While grid storage batteries are a sector with great business opportunities as the renewable energy market expands, in Japan they are also an area where grid interconnection procedures, market systems, and the division of labor among the relevant operators are intricately intertwined.
Even among the authors involved in battery storage-related projects in the ASEAN region, the Japanese market has a particularly close connection between the system and practice, and I feel that the ingenuity of the system's construction makes it easy to determine the success or failure of a business.
As I personally deal with both legal and business aspects of this field every day, I am very conscious of both the issues that cannot be resolved by contracts alone, and the legal risks that are easily overlooked by on-site experience alone.
If you have any problems with the reorganization of the grid battery business, the division of contracts with EPC, aggregator, and SIer, the division of responsibilities, or the design of risk allocation, Blog contact page Please feel free to contact us at. We also handle initial online consultations.
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