William Cassilly — Author | PES Supply
Industry Analyst & Principal Contributor at Portlandia Electric Supply (PES Supply), a PES Global Group company.
William Cassilly is the principal industry voice at Portlandia Electric Supply. He covers solar and electrical market trends, trade and tariff policy, energy demand, and equipment buying strategy for contractors, installers, and commercial buyers. His analysis is grounded in PES Supply's day-to-day work sourcing and supplying 50,000+ SKUs from 169 authorized brands across the United States.
Articles by William Cassilly
A selection of recent articles. Browse all on the PES Supply News blog.
- Growing Electricity Demand: Why Energy Policy Reform Is More (2026-07-24)
- Newest Solar Panels in 2026: Latest Models from Leading U.S. (2026-07-18)
- How Can a Residential ESS Achieve 0W Grid Flow? (2026-07-14)
- How Automatic Transfer Switches Work (2026-07-12)
- Solar Panels for 10,000 kWh/Month: 2026 Sizing Guide (2026-07-06)
- 7 Benefits of Switching to Commercial Solar Energy (2026-06-30)
- The Main Types of Solar Panels: Which Should You Choose? (2026-06-26)
- America's Largest Clean Energy Project Goes Live After Nearl (2026-06-26)
- How to Find Local Solar Companies Near Me (2026-06-14)
- How Long Do Solar Panels Last? (2026 Guide) (2026-06-14)
- What Questions Should I Ask My Solar Company? (2026-06-14)
- Is Solar Worth It for My Home? (2026-06-10)
Portlandia Electric Supply carries 50,000+ SKUs from 169 authorized brands across solar, electrical, energy storage, and EV charging. Questions about an article or a project? Call (888) 876-0007 or email sales@pes.supply.