BRP, aggregator and balance responsibility: Who does what in the value chain?

When a battery takes part in the electricity market, several roles appear that are easy to mix up: balance responsible party, balancing service provider, aggregator and asset owner. For an industrial business, it matters who does what, because that decides what the business itself must do, what it signs, and what others handle on its behalf.

This article is an actor map. It explains the central roles in the value chain around a battery, why owning an asset does not in itself make anyone a market participant, and where ZynexGroup sits in the picture. The aim is to make an otherwise opaque chain concrete, so it is clear what is the customer's responsibility and what others handle.

Balance responsible party: the one who carries balance responsibility

The balance responsible party, often abbreviated BRP, is an actor that is approved by and has entered into an agreement with Energinet (Denmark's national transmission system operator) to carry out balance responsibility. Balance responsibility means that someone must stand financially accountable to Energinet for the difference between what was planned and what actually happens.

In practice, balance responsible parties buy and sell electricity on the power exchanges on behalf of electricity suppliers and asset owners. They send daily schedules to Energinet for expected production and consumption and are financially responsible for imbalances between the expected and the actual, as described by Energinet. Imbalance settlement itself is handled across the Nordic region by eSett. The point is that balance responsibility is a formal, financial role with an agreement with Energinet, not something every asset owner automatically holds.

To understand why the role exists, it helps to look at what an imbalance is. The electricity system is planned in advance: schedules are submitted for how much is expected to be produced and consumed in each period. In reality, the actual outcome always differs slightly from the plan. That difference is an imbalance, and someone must carry the financial responsibility for it toward the system. That is precisely the task the balance responsible party takes on, and it is why an asset cannot simply connect to the market without a balance responsible party behind it.

Balancing service provider: the one who delivers the reserves

Another role is the balancing service provider, often abbreviated BSP. This is the actor that delivers the ancillary services themselves, for example aFRR or mFRR, and that is approved for that under the applicable prequalification requirements. A BSP can be an electricity producer, an electricity consumer or an aggregator, and it does not need to be the same as the balance responsible party.

The distinction between BRP and BSP is worth holding onto. One carries the financial balance responsibility; the other delivers the technical service. Sometimes both roles are held by the same company, but they are legally distinct, and a battery can participate through one, the other or both, depending on the setup.

Aggregator: the one who pools multiple assets

An aggregator pools multiple assets into a portfolio so that together they can meet the market's requirements. The term independent aggregation business covers an aggregator that is not affiliated with the customer's own electricity trading company. Since 1 January 2025, aggregation businesses have, under the executive order on aggregation, the right to participate in all electricity markets on non-discriminatory terms, and their access does not require the consent of other market participants. That right builds on the EU electricity market directive, which establishes that market participants engaged in aggregation, including independent aggregators, can enter the markets without others' consent.

For a battery owner, the aggregator is often the practical path into the market. Instead of having to meet the market's requirements alone, the asset joins a larger pool that the aggregator administers and bids into on participants' behalf.

Owning a battery does not make you a market participant

A point often overlooked is that owning a physical asset is not the same as being a market participant. An asset owner typically sells its electricity through an electricity supplier, which in turn works with a balance responsible party that places the production in the market. Market access therefore sits in the market-facing roles, not in ownership of the asset.

The same applies to ancillary services. To bid into the markets for reserves, an asset owner must either work with a balance responsible party or a balancing service provider, or become approved as one of those itself, as Energinet describes in its outlook for ancillary services. Prequalification can happen either as a standalone asset or as part of an aggregated portfolio, per Energinet's prequalification framework. That framework is what makes it possible to pool several smaller assets.

Why size matters

Part of the reason these roles exist is that the markets require a certain minimum size. Several ancillary service products have a minimum bid size of around 1 MW, as set out in Energinet's tender conditions. A single smaller industrial battery cannot necessarily deliver that much power on its own, and the requirements also vary between products. That is why it makes sense to pool several assets into a portfolio that together reaches the requirements. It is the aggregator's and the balance responsible party's role to make that pool function as one market participant, even though it consists of many small units.

This is also where market access is really decided for the smaller assets. A battery that is too small to participate on its own is not shut out of the market, but it depends on joining a pool. Who runs that pool, and on what terms, therefore becomes a central question for a smaller asset owner.

Where ZynexGroup sits in the value chain

Our role is to deliver and coordinate the asset and to handle commercial optimisation through a partner. We are not ourselves a balance responsible party, and we do not trade in the customer's name on the markets. The market-facing roles, including balance responsibility and bidding into the markets, sit with our partner.

One point is worth highlighting. The markets often have minimum size requirements that make it difficult for smaller assets to participate directly. Through our own platform, we can help smaller sites that would otherwise fall below typical partner requirements to join the partner network. In that way, smaller grid connections can also enter the market through our setup, without the customer having to meet the requirements alone. That is facilitation of market participation, not an offer for the customer to trade on the market themselves.

What the customer signs, and what ZynexGroup handles

For the customer, the picture is simple: the customer enters into an agreement with ZynexGroup. We and our partner handle the market-facing roles, the technical optimisation and access to the markets. The customer therefore does not need to enter into an agreement with a balance responsible party itself or prequalify the asset itself.

In our standard model, the customer receives a fixed contractual availability payment, while the commercial optimisation and any market revenue it may generate accrue to ZynexGroup for the agreement period. In other words, the customer signs an agreement for an asset and an availability payment, not an agreement to become a market actor. Market access is something we facilitate through the value chain, not something the customer has to run themselves.

That distribution has a practical consequence worth highlighting. Balance responsibility involves financial risk: the balance responsible party is accountable for imbalances and for movements in the market. When that role sits with our partner and not with the customer, it is also the partner and ZynexGroup that carry that risk in the standard period, in return for the customer accepting a fixed payment rather than variable market revenue. The customer is thereby relieved of both the administrative work of being a market actor and the exposure to market fluctuations.

That does not mean the customer has nothing to consider. It remains useful for the customer to understand what the agreement covers, which roles are handled by whom, and what applies after the agreement period. But the ongoing operation as a market actor, including balance responsibility, bidding and optimisation, sits with us and our partner, not with the customer.

Overall perspective

The value chain around a battery consists of several roles: the balance responsible party, which carries the financial balance responsibility; the balancing service provider, which delivers the reserves; the aggregator, which pools assets into a portfolio; and the asset owner, which owns the physical asset. Owning the asset does not in itself make the owner a market participant. Market access sits in the market-facing roles.

For an industrial customer, the useful point is that ZynexGroup and our partner handle those roles so the customer does not have to. We are not a balance responsible party, but we ensure that the asset can take part in the markets through the value chain, and the customer receives a fixed availability payment rather than having to act on the market themselves. When reading about BRP, BSP and aggregators, it is therefore worth remembering that the roles describe how the market works behind the scenes, not what the customer itself must do. For the customer, the entry point is one agreement with us, and we and our partner make the rest of the chain work together.

Assessing the potential for your site

If you want to know how an industrial BESS asset can specifically take part in the markets through us and our partner, we start from your own data: grid connection, consumption profile and history. On that basis we prepare an initial assessment of whether there is a match, and what the next step could then be. You are welcome to contact us.