Thanks AmyC.
Also found the following information:
https://www.irs.gov/pub/irs-pdf/i5695.pdf (see section Residential Clean Energy Credit (Part I) on page 1)
https://ttlc.intuit.com/community/state-taxes/discussion/i-am-installing-solar-pv-systems-on-two-hom...
https://ttlc.intuit.com/community/tax-credits-deductions/discussion/i-have-a-second-home-can-i-claim...
