BESS & Hybrid Parks

Why Optimisation Is Becoming Critical for Renewable Energy Projects

Battery energy storage systems are often discussed in terms of their revenue potential. In project development practice, however, the business case starts much earlier: with the grid connection, site-specific conditions, curtailment risks and the question of whether flexibility can actually be utilised.

BESS and hybrid parks are considered as key levers for making renewable energy assets more economically resilient. This is not solely due to the potential for additional revenue streams. Crucially, battery storage can decouple electricity generation from its sale in the market. This makes it a tool for managing redispatch, negative electricity prices, volatile price profiles and limited grid capacity.

For project developers, investors and asset managers, this means that a BESS is more than merely a technical addition to a wind or solar PV project. It changes the logic of the project itself. The storage system affects which revenue streams can be accessed, the extent to which grid constraints influence the project, which site-related issues must be clarified first and whether a concept can ultimately be developed into a bankable project.
This article marks the launch of our BESS Insights series. It explains why optimisation is becoming increasingly critical for renewable energy projects and why the business case does not begin with the financial model.

Why Flexibility Is Becoming a Value Driver

The economic environment for renewable energy assets is becoming increasingly complex. Wind and solar PV projects are operating within an energy system in which generation peaks, grid congestion and price volatility increasingly occur at the same time. Under these conditions, generating as much electricity as possible is no longer sufficient. What matters most is when—and under what grid and market conditions—electricity is fed into the grid or stored temporarily.

BESS can make a structural contribution in this context. They can shift generation over time, smooth feed-in profiles, take advantage of short-term price opportunities and stabilise the economics of an asset. Flexibility therefore becomes a value driver. It is not a supplementary function to be added at a later stage, but a feature that must be considered from the outset of project development.

Anyone who views a BESS project merely as additional hardware is therefore missing the point. From an economic perspective, storage is primarily an optimisation tool: for market value, utilisation of the grid connection, PPA structures, risk profile and operational control.

Redispatch, Negative Prices and Volatile Price Profiles

The pressure to optimise arises particularly where generation patterns diverge from grid or market conditions. Redispatch, curtailment and negative electricity prices demonstrate that renewable electricity generation does not automatically translate into predictable revenues. Simply expanding generation capacity will not solve this problem if flexibility and grid connection capacity do not grow at the same rate.

Negative prices are a particularly visible indicator of this imbalance. They show that, at certain times, electricity is not merely worth less but may become an economic burden. For subsidised assets and PPA structures, periods of negative prices can have a significant impact on cash flow, market value and revenue forecasting.

A BESS cannot eliminate these effects across the board. It can, however, help reduce exposure to unfavourable market and grid conditions. Whether it succeeds in doing so depends on the project setup, charging strategy, technical availability, regulatory framework and route-to-market strategy.

Why the Grid Connection Limits the Business Case

In many projects, it is not the battery itself that is the limiting factor, but rather the grid connection. Available grid capacity, existing connection rights, potential operational restrictions, and the classification of the storage system determine which project setup is realistically feasible.

The business case therefore begins earlier than is often assumed. Before revenue streams are modelled, it is necessary to establish whether sufficient grid or converter capacity is available, whether an existing generation asset can be integrated and whether additional charging from the grid is permitted or the battery may only be charged using renewable electricity.

This preliminary assessment is particularly important for hybrid parks. A storage project may appear commercially attractive but still be constrained by the grid. Conversely, an existing grid connection may provide a strong rationale for co-location if it allows flexibility to be utilised more quickly or efficiently.

Which Site-Specific Issues Must Be Clarified Before Financial Modelling

Before developing the financial model, a number of straightforward but critical site-specific questions must therefore be addressed: Is there an existing wind or solar PV asset? Is grid capacity limited? Is the asset already subject to curtailment? Is the project integrated into a PPA structure? Is spare converter capacity available? Are suitable control systems in place? Is there sufficient space for battery containers, transformers, cable routes, construction activities and ongoing operations?

The answers determine whether a co-location model, a stand-alone BESS or a hybrid structure is most appropriate. They also determine whether the storage system should primarily be used for asset optimisation, to capture market opportunities or to combine several revenue models.
The key conclusion is that a BESS setup is generally opportunity-driven rather than purely market-driven. It follows the actual conditions at a particular site. Only once those conditions have been established on a reliable basis can the commercial viability of a particular revenue model be meaningfully assessed.

What This Means for BESS and Hybrid Park Projects

For project development, this means that optimisation is not a task to be addressed at a later stage. It forms part of the project’s fundamental structure. The grid connection, site, charging strategy, revenue model and technical implementation must be considered together. Otherwise, there is a risk that a project may appear attractive in the financial model but ultimately fail during implementation due to grid constraints, regulatory limitations or interface risks.

BESS can improve the economics of wind and solar PV projects. They can stabilise market value, reduce curtailment, unlock additional revenue opportunities and provide flexibility that supports the wider energy system. Whether they actually deliver these benefits, however, depends on the specific project structure.
The key question therefore is not: Which storage system fits the business case? Rather: Which project setup is viable under the specific grid, site and market conditions? This question marks the starting point for every commercially viable BESS development.

Outlook: The Next Article

The next article in our BESS Insights series will examine which setup is suitable for which type of project: co-location, stand-alone or hybrid. It will focus on when storage primarily serves to optimise an existing renewable energy asset and when a more market-driven model may be the better option.

FAQ

Working Basis

The content is based primarily on the presentation slides covering target setting, redispatch, and price curves; Section 51 of the EEG / negative prices; basic requirements for BESS development; and setup options from the presentation “BESS & Hybrid Parks as an Asset Optimization Tool” held on June 9, 2026, in Hamburg.

Legal Status / Disclaimer

This article is intended to provide general guidance and does not replace project-specific legal, technical, tax, or financial advice. The regulatory analysis reflects the state of the discussion as of the date of publication and is subject to change. Last updated: July 2026.