6.4 The panel

Outcome 4 of 8 in domain 6 · Power, panels, packs, motors, converters

PV cell, I-V curve, maximum power point, PWM or MPPT controller, sizing a small off-grid system.

My targets

I declare:

Explain the photovoltaic cell, its open-circuit voltage, its short-circuit current, and why a panel is a current source more than a voltage source.
Plot a panel’s I-V curve in the sun and in partial shade, and show what the shadow of a single cell does to the whole.
Explain the maximum power point and compare, by measurement, a PWM controller and an MPPT on the same panel.
Size a small 12 V off-grid system: daily consumption, days without sun, panel, battery, controller, wire gauge.
Build the system, measure what it produces over a week of autumn at home and compare to the calculation.
Explain orientation, tilt and seasons for a panel in Canada, and wire two panels in series then in parallel, saying what each arrangement changes.
Diagnosis: a panel that "no longer charges", bypass diode, connector, shade, or full battery; where to start.