Per IRS Form 8908 instructions:

Purpose of Form
Eligible contractors use Form 8908 to claim a credit for
each qualified energy efficient home sold or leased to
another person during the tax year for use as a residence.
The credit is based on the energy saving requirements of
the home. The credit is part of the general business credit.
Partnerships and S corporations must file this form to
claim the credit. All other taxpayers aren’t required to
complete or file this form if their only source for this credit
is a partnership or an S corporation. Instead, they can
report this credit directly on line 1p in Part III of Form 3800,
General Business Credit.
See section 45L for more information.