Install solar panels on concrete tile with skip sheathing

Hello, I live in California bay area. My roof type is concrete tile with skip sheathing. The roofer checked the roof and said it is in satisfactory condition, even it has been 40 years.

I asked Sunpower and Sunrun to install solar panels, but after they did onsite survey, they said I need to replace my roof, another $10000+. I am reluctant to do that, since my roof has nothing wrong.

Do you know if there is a way to install solars on this type of roof, without replacing roof? I saw some of my neighbor has solar panels on the similar type of roof. I am not sure if they made some improvement internally.

Thanks