Why “Perfect” Battery Models Keep Failing in Reality - Harmony Energy

Most BESS revenue forecasts aren't wrong, they're just being used for the wrong thing. The gap between a valuation-grade forecast and what a project actually earns in a live market is where BESS developers win or lose. The developers who survive that gap are the ones who design for uncertainty from the start - not after the fact.

Recorded live at the Investing in Battery Energy Storage conference, Paul Mason, Chief Investment Officer of Harmony Energy, joins Ed Porter for a return appearance on Transmission.

They cover:

- Why treating a revenue forecast as a fixed cash flow is the most common mistake in BESS development.

- How the listed fund model enabled GB BESS to scale.

- Why splitting BESS revenues into ancillary, wholesale, and balancing mechanism streams is now a misleading framework.

- How Harmony selects new markets in France and Germany: renewable penetration, grid-first site selection, and why any business case dependent on high ancillary revenues is a losing strategy.

- What good optimizer relationships actually look like.

Got follow-up questions? Ask Ko, Modo Energy's AI analyst : https://modoenergy.com/sign-up?utm_source=podcast_apps&utm_medium=podcast&utm_id=paul_mason

Watch on YouTube: https://youtu.be/a2--s956k-c

⏱ CHAPTERS

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0:00 Introduction

1:16 What do BESS developers get wrong when building an IPP?

3:25 Why full EPC contracts — and why they still hired project managers

5:28 Duration strategy: the case for 2-hour batteries early

7:00 The full BESS lifecycle — develop, build, operate, sell

8:25 How Harmony raised capital through listed funds (and why it worked then)

10:45 Why listed fund capital flowed out and what came next

13:20 The Foresight asset sale: private vs. public valuation

15:08 New markets: what Harmony looks for in France, Germany and beyond

18:05 Market timing — should you enter early or wait for wholesale dynamics?

20:12 Grid connection across Europe: where it works and where it doesn't

22:33 Operating a live fleet: what drives performance once assets are running

24:10 How to work with optimizers without burning the relationship

26:30 BM trading trials with Tesla — what the data showed

28:45 Is GB still exciting for Harmony, or is it old hat?

30:20 Audience Q&A: colocation, revenue cannibalization, and market saturation

32:35 If you ran European power: one thing to fix

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Transmission is hosted by Ed Porter, Director EMEA & APAC at Modo Energy.

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