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Each calculator adds its lines to a single estimate — consolidated BOM, schedule and cash-flow included.

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Solar & Energy Storage

Array sizing, inverters, battery banks, off-grid autonomy and standby generation.

Solar calculations mislead most often through the gap between nameplate and delivered energy. An array reaches its rated output for a handful of hours a year, a battery delivers a fraction of its rated capacity as usable energy, and an inverter is deliberately smaller than the array it serves. Every page in this category works in the delivered figure and shows the nameplate alongside it.

Off-grid sizing has one rule that overrides the arithmetic: size on the worst month, not the annual average. Peak sun hours in a northern winter can be a third of the summer figure, and a system sized on an average leaves you dark in the month you least want it to. Where a page uses a solar resource figure, it asks for yours rather than assuming a favourable one. The same discipline applies to storage: a battery is quoted here in the energy it will actually deliver after depth of discharge and round-trip losses, which for lead-acid chemistries is closer to forty percent of the nameplate than to all of it.

Battery Bank Sizing Calculator

Size a battery for a daily load and days of autonomy — with the usable capacity, not the nameplate.

Off-Grid Autonomy Calculator

Work out how long a battery bank runs a given load, and how much array is needed to replace it each day.

Solar Inverter Sizing Calculator

Size an inverter to an array, including the deliberate over-sizing of DC to AC that improves real yield.