Enter your billing period, usage, and region. We'll run three models against real wholesale price data — from basic load shifting through to full battery arbitrage — and show you what each approach would have cost.
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Warden watches prices every 5 minutes and acts the moment it's cheap.Wholesale cost only — does not include lines charges, retailer margin, metering, or GST. Unmanaged: load weighted by NZ residential demand shape (morning and evening peaks) at average wholesale price — reflects when people actually use power, not a flat average. Smart scheduling: 65% of daily load shifted to the cheapest contiguous 3-hour window between 7pm and 6am each night (EV charging, heat pump hot water, spa pool, dishwasher, dryer); 35% at average price. Battery: daily arbitrage — charge during cheapest window, discharge during most expensive, 90% round-trip efficiency, net cost floored at zero. One charge/discharge cycle per day modelled; active management with Warden can identify multiple daily opportunities. Historical data at 30-minute resolution; data from May 2026 at 5-minute resolution. Source: EA Wholesale Information & Trading System (WITS). emi.ea.govt.nz