Battery Energy Storage (BESS).

A UPS battery sits idle waiting for grid failure; a BESS is sized larger and controlled to discharge during peak-tariff hours, absorb solar and provide backup — same chemistry, three shifts. A UPS battery exists to bridge the gap between mains failure and generator startup; it sits idle the rest of the time. A BESS is sized larger and controlled by a smarter inverter that allows it to discharge into the building during peak-tariff hours, absorb surplus solar, and provide grid services in addition to backup. The same lithium chemistry can do both jobs in a hybrid topology — that's what we mean by 'three shifts'.

It depends on tariff exposure and topology, not a published figure. Buildings with significant peak-demand charges and a good peak/off-peak tariff spread see the fastest return from peak-shaving; where rooftop solar export tariff is poor, self-consumption is the stronger case; mission-critical hybrid topology (where the BESS is also the UPS battery) builds the case on lifetime-cost displacement of VRLA rather than tariff arbitrage. We model your tariff exposure and load profile and share the commercial case — including an indicative payback — in a written estimate after review.

Specify LFP (lithium iron phosphate) for stationary BESS — better thermal stability, longer cycle life, lower fire risk; NMC only for weight-or-footprint-critical applications. LFP is the default for stationary BESS. Better thermal stability, longer cycle life, more tolerant of deep discharge, lower fire-risk. NMC (nickel manganese cobalt) has higher energy density per kg and is appropriate where weight or footprint is critical and operating temperature is controlled. For 95% of the buildings we engineer, LFP is the right answer.

An LFP BESS lasts 16+ years cycled once daily for peak-shave or 8–10 years cycled twice daily for arbitrage — 6,000+ cycles at 1C discharge to 80% retained capacity. 6,000+ cycles at 1C discharge to 80% retained capacity. Cycled once per day for peak-shave that's roughly 16+ years; cycled twice per day for arbitrage closer to 8–10 years. We specify and warranty against actual usage profile, not against an idealised cycle count.

Yes for short windows; continuous off-grid operation needs solar generation exceeding daily consumption plus a BESS sized for night-time — that's microgrid territory. Sizing the BESS to building-level autonomy is what 'mission-critical' deployments do. For continuous off-grid operation you need solar generation that exceeds daily consumption plus a BESS sized for night-time operation; that's microgrid territory and we engineer it where the location and economics support it.

BESS AMC includes quarterly cell-bank impedance and temperature reviews, annual capacity tests, BMS firmware management and a spare-cell pool — written response targets in contract. Cell-bank impedance and temperature trend review, annual capacity-test report, BMS firmware management, balancing-routine verification, and integration health-check with the building's BMS. We hold spare-cell and BMS-board pool for active deployments; response targets are written into the contract.