Picking the right duration is one of the single biggest calls for battery investors in Great Britain. Too short, and you miss wholesale opportunities; too long, and the extra capacity won't recover the investment cost.

The biggest factor in determining the duration to choose for a battery energy storage system (BESS) is the cost to build that battery. BESS CapEx can range from project to project and from year to year, making the decision on what duration to build less set in stone.

This analysis runs every grid supply point zone, eight possible durations, several cost paths, and two commissioning windows starting from 2026 to 2030. The results show a clear, if shifting, sweet spot.

This article breaks down:

• The significance of CapEx on choosing duration
• The impact of future revenues on choosing duration
• How CapEx and revenue trends interact
• What the best answer is

Key takeaways