SOLARA
Sustainability intelligence platform
HomeDesignSolar & Storage
Module 03 · Pre-build

Can the facility run on solar — and when does it fail?

An 8,760-hour dispatch of the Module-02 load against a candidate PV array and battery, using Module-01 weather. The same engine sweeps the full PV × storage design space to find the zero-shortfall point.

Annual load
MWh / yr
PV generation
MWh / yr
Self-sufficiency
% of load met
Shortfall hours
hr / yr (%)
Deepest deficit
kW (single hour)
Longest dark streak
consecutive hours

Monthly failure profile

When in the year does the system fail? Winter solar shortfall (December–February) dominates.

Worst week — hourly energy flows

The 7-day window with the most unmet kWh. Battery state-of-charge (right axis, dotted) drains during long cloudy stretches and cannot recover.

Mean daily energy curve

Average kW across all 365 days. PV peak (midday) versus load peak (photoperiod) drives the storage requirement.

Hourly shortfall heatmap

365 days × 24 hours. Dark red = the highest unmet kW.

Design space — when does shortfall reach zero?

Each row is a battery size, each column a PV size. Annual shortfall hours decrease toward the upper-right. The current Farm32 design (480 kWp, 600 kWh) is marked.

Methodology

PV model

pvlib PVWatts at 30° south-facing tilt, 14% system losses, hourly POA irradiance & cell temperature from the Module-01 TMYx file. No tracking; mono-Si modules at 200 W/m².

Battery model

LFP chemistry, 92% round-trip efficiency, 90% depth-of-discharge, 150 kW power cap (independent of energy). Self-discharge negligible at hourly resolution.

Dispatch logic

Greedy hourly priority: PV serves load first; surplus charges the battery; deficit draws from the battery; residual is recorded as shortfall. No grid export, no curtailment penalty.

Design sweep

240–960 kWp × 300–3,600 kWh battery — 80 combinations, full 8,760 h re-run each. The zero-shortfall contour line is overlaid on the heatmap.

Outputs handed downstream

OutputGoes toHow it is used
Sized PV (kWp) + battery (kWh)Module 04 — Environmental ImpactCapital-goods stage: PV module + inverter + battery bill of materials
Grid import / export (MWh/yr)Module 04 — Environmental ImpactOperational energy stage (PEFCR §5.3) — grid mix EF
Hourly dispatch baselineOperateReal-time deviation against measured PV + battery output