Battery storage presents investors with an unusual problem. The asset is simple, the construction risk is modest by infrastructure standards, and the technology is well understood. The difficulty is entirely on the revenue side, and it is structural rather than temporary.
Storage earns from several sources at once. The mix between frequency and balancing services, wholesale arbitrage and capacity payments shifts as connected capacity grows, and the services that were most valuable when a project was conceived are frequently not the ones paying for it when it energises. Underwriting therefore requires a view of a market several years out, which is precisely the exercise most investment committees are least comfortable with.
Three responses
Capital has broadly settled into three positions.
- Contract the volatility away. A tolling agreement transfers the revenue risk to a counterparty in exchange for a fixed payment. Returns are lower and financeability is materially higher. This is the route most debt providers now prefer.
- Floor it. Floor mechanisms with an upside share leave some exposure with the owner while giving lenders a downside they can size against. It has become the practical middle ground for portfolios of scale.
- Take the risk deliberately. A smaller pool of specialist investors accepts merchant exposure, prices it explicitly and manages it through active optimisation. This capital exists but it is not cheap, and it is not persuaded by a base case built on last year's spreads.
What developers should evidence
The projects that raise capital are rarely those with the highest modelled return. They are the ones where the connection date is firm, the duration matches the market being targeted, the cell supply position is contracted, and the augmentation and degradation assumptions are consistent with the warranty actually held rather than a manufacturer's datasheet.
One further point is routinely underestimated. The optimiser arrangement is a commercial decision that materially affects revenue, and investors will read it closely. Presenting it as an operational detail to be settled later suggests it has not been thought about.
The market position
Storage remains one of the more attractive parts of the transition for capital, precisely because volatility is the source of the return rather than a threat to it. What has changed is that the argument now has to be made with structure rather than enthusiasm.
This article is general commentary. It is not investment advice, a recommendation or an offer, and it does not take account of the circumstances of any particular party. Juliet Rose Capital introduces only and does not provide advice on investments.