I have a second home can I claim energy credit for that home and my main home?

It depends on what kind of energy property you installed. 

You can claim the Residential Energy Efficiency Property Credit for solar, wind, and geothermal equipment in both your principal residence and a second home. But fuel-cell equipment qualifies only if installed in your principal residence.

Can you state your source regarding the second home?  It's pretty clear that it has to be your "main home" and by virtue of being the "second home" it would NOT be the place you "live most of the time".

Residential Energy Efficient Property Credit (Part I)

If you made energy saving improvements to more than one home that you used as a residence during 2020, enter the total of those costs on the applicable line(s) of one Form 5695. For qualified fuel cell property, see Lines 7a and 7b, later.

Also see

https://www.law.cornell.edu/uscode/text/26/48