Vertical panels will definitely help reduce the risk to dusk build up which will help. However, so storms do reduce sun a lot. Large batteries will help, but not for the big ones. Here's some examples.
Here are the approximate durations of three Martian global dust storms, based on NASA observations and scientific analyses:
2018 storm — Began late May/early June 2018 (detected around May 30–June 2). It rapidly became planet-encircling by mid-June, peaked in late June/early July, and began decaying in August. Elevated dust levels persisted until mid-September to mid-October 2018, with the full event lasting about 4–5 months (the period of severe global impact and low sunlight was several months, ultimately leading to the loss of the Opportunity rover).
2007 storm — Started in late June/early July 2007 and expanded globally over the following weeks. It lasted several months (roughly 3–4 months of significant activity), severely impacting the Spirit and Opportunity rovers (which survived in low-power mode).
2001 storm — Initiated in late June 2001 (around June 25–26) near Hellas Basin. It quickly became global, with major activity largely subsiding by late September 2001, though the atmosphere remained hazy into November. The core global phase lasted about 3 months, with periods of near-total sunlight blockage up to that length in affected areas.
Global dust storms vary in exact length depending on how "duration" is defined (e.g., from onset to full decay vs. peak intensity), but they typically persist for weeks to several months, far longer than local or regional storms. The periods of extreme dimming (90–99% sunlight blockage) often span 1–3 months during the peak.
RE: Mars Independence 7/12: Energy Roadmap