The 2017 hurricane season wrought immense destruction to the electricity grid across the West Indies, most visibly in Puerto Rico, the U.S. Virgin Islands and Barbuda. Not only did high winds knock down power lines, they tore away solar panels that otherwise could have provided power after the storm clouds parted. In contrast, finds the Rocky Mountain Institute (RMI), solar facilities in the British Virgin Islands, the Turks & Caicos, and St. Eustatius, survived winds reaching 180 miles per hour.
What was the difference? Installation standards.
RMI sent structural engineering teams to the Caribbean to find out why some solar structures survived nearly unscathed while others disintegrated.
The teams noted similarities between the failed systems, including module clamp failures, undersized racks, undersized and under-torqued bolts, a lack of bolt locking solutions, and a lack of lateral racking support. On the flip side, the systems that survived had the modules through bolted (no clamps), bolts with locking solutions, and lateral racking supports.
Making solar arrays more resilient in the face of natural disaster in the Caribbean would add only 5% in engineering, procurement, and construction, PMI estimates.
The Caribbean is far more exposed to hurricanes than Virginia is, but the questions PMI raises are certainly relevant here as the Commonwealth embarks upon an unprecedented build-up of solar capacity. Virginia could be getting as much as a quarter of its electric power from solar within 20 or 30 years. We want to make sure that power comes back on after a natural disaster.
What construction standards would be required to ensure that solar panels held up to a hurricane? Would the same standards need to apply across the state, or could they be relaxed for solar capacity farther from high-speed winds along the coast? How resilient would Virginia’s electric grid be if a hurricane knocked out 10% or 20% of the state’s solar capacity? Could we import enough power from elsewhere in the PJM Interconnection grid? How much would it cost to protect against a worst-case scenario?
As Virginia moves towards a solar future, I would think that these questions are worth asking.
