battery energy storage system with solar panels and wind turbines behind battery energy storage system with solar panels and wind turbines behind
Bess

Tales of BESS #2 - Case Study : Due Diligence on Belgium's biggest BESS project

Jul. 18, 2025
2 minutes

Due Diligence on Belgium’s biggest BESS project : 50MW / 100MWh (BL)

Greensolver performed the technical due diligence of the largest BESS project in Belgium 50MW/100MWh in the context of the project’s financing.

This audit covered both:

Technical aspects:

  • Site assessment & permitting : grid connection agreement, permits, EIA, connection signal with TSO, compensatory measures
  • Review of the selected equipment
  • Design review and capacity to operate on primary reserve markets, calculation of “puissances valorisables”
  • Contracts review: BESS supply & maintenance, construction, RTM, TSO
  • Insurance policy coherence with technological risks

Financial/aspects:

  • Audit of the revenue scenarios and Assumption sheet (revenue stacking), including FCR, aFRR, CRM, voltage supply markets, imbalance market
  • Review of the inputs of the financial model and validation of the Assumption sheet : CAPEX, OPEX, budgets, revenues, IRR

Based on the reviewed technical capabilities of the BESS project, Greensolver audited the expected revenue streams of this BESS project. Our best expert analysed the very detailed financial models provided by the project developer, encompassing all the types of (ancillary) services to be serviced by the BESS, according to its constructive capabilities.

Our expert detected many inconsistences & issues in the financial model due to assumptions with needed to be modified and discussed with the project’s sponsors, its consultant and the potential lenders.

These discussions allowed to have more a robust financial model. Our expert has also identified points of attention to be discussed and negotiated with the RTM operator and the TSO, in order to achieve the revenues and the economics of the BESS.

Written by David Roissé

Blog

The Latest Renewable Energy News

Solar panels with sheeps around like agri-pv

Agrivoltaics – Dual Land Use, New Incentives, and Market Opportunities

Handshaking by two women

Why will certifications become necessary in 2026?

Solar Panel with Blue sky

Grid Availability and Curtailment: The Hidden Drivers of Solar Asset Performance

Sun with ondulations in purple

Smart Coexistence: When Sheep, Solar, and AI Work Together

Team of people at a conference

Greensolver will be in Montpellier for Energaia – 10 of december

Battery energy storage open

What the Update to NFPA 855 Means for Energy Storage Safety ?

Battery energy storage open with cables

Tales of BESS #11 – Case study: Technical Due Diligence for BESS project: 17.75MW / 35.5MWh (FR) 

Battery energy storage contener

Tales of BESS #10 – Case study: Technical Due Diligence on two Greek BESS projects: Totaling 100MW / 200MWh (GRC) 

Solar farm with solar panels with grass

Safety Concerns in Single-Axis Tracker PV Plants: Risks and Mitigation Strategies

Resources and insights Tales of BESS #2 – Case Study : Due Diligence on Belgium’s biggest BESS project