A Hawaii solar company is pushing a new option to add batteries and panels to older home solar systems, which is good news for homeowners facing higher power bills and storm outages.

• The RetroKit add-on lets people with existing solar bolt on battery storage and extra panels without losing their old net metering deal with the utility.
• Batteries are the big draw now — they cut electric bills and keep the fridge and lights running when storms knock out the grid, as recent Kona low outages showed.
• Hawaii's state tax credits for solar and batteries are still generous this year, but changes kick in next year that make them less attractive.
• Extra help comes from Hawaiian Electric rebates on batteries and local credit union loans with no interest and no payments for two years.

Outlook: Homeowners have a narrow window to lock in the current, richer tax credits before the state trims them in 2027.