Local Solar Installer Kapili Energy Raises $18M to Expand Residential Battery Storage

Kapili Energy, a Honolulu-based solar and battery storage installer, has closed an $18 million Series B funding round led by Elemental Excelerator and joined by Ulupono Initiative and mainland climate fund Congruent Ventures.

The company plans to use the capital to triple its installation capacity and launch a new community solar program targeting renters and condo owners who can’t install rooftop panels. Kapili currently operates on Oahu and Maui and will expand to Hawaii Island and Kauai by year’s end.

“Hawaii has the highest electricity rates in the nation and the most sunshine,” said CEO and co-founder Nalani Rodrigues. “The economics of solar-plus-storage here are better than anywhere else in the country, but we’ve barely scratched the surface on multi-family housing.”

Kapili’s business model pairs rooftop solar installations with Tesla Powerwall or Enphase battery systems, allowing homeowners to store daytime solar generation for evening use and reducing dependence on the HECO grid. The company has installed over 3,200 residential systems since its founding in 2022.

The community solar initiative will allow renters to subscribe to shared solar arrays and receive credits on their HECO bills. Kapili is partnering with three large condo associations in Kakaako and Ala Moana for pilot projects launching this summer.

Hawaii’s aggressive clean energy mandate — 100 percent renewable electricity by 2045 — has created a booming market for solar installers. But Rodrigues noted that Hawaii still has roughly 280,000 residential ratepayers without access to solar, most of them renters or condo residents, representing a massive untapped market.