Most NZ battery projects fail due to poor design—not cost or performance. Common mistakes include confusing power vs energy, poor siting, and underestimating approvals. A well-designed BESS can pay back in 5–7 years and cut peak demand costs by up to 50%. The key steps: Understand your load (kW peaks, kWh usage, timing) Size power and energy correctly Choose the right chemistry (LFP vs vanadium flow) Select the right system size Plan site and access properly Engage the lines company early Allow for consents and timelines Complete proper commissioning