Is anyone aware of any directories of private lenders that finance energy efficiency projects through PACE (or other) programs in the northeast for larger commercial, multi-family, and industrial projects (specifically CT, MA, NJ, and PA)?

Each state in the Northeast has a directory of lenders for their C-PACE program. Connecticut is one of the most active states for C-PACE in the country so, they have several lenders listed. I would also suggest New York and Pennsylvania as good sources for C-PACE lenders. The C-PACE Alliance is trade organization of the lenders. https://www.c-pacealliance.com/about-cpa/members/

CT:  https://www.cpace.com/

NY: https://accelerator.nyc/resources/finance/pace

PA: https://pennsylvaniacpace.org/wp-content/uploads/sites/4/2022/04/C-PACE-Capital-Providers-List-20220408.pdf

You may also want to look at the program administrator’s website.  For example, EIC runs New York State PACE (outside NYC) and has a list on its website here.  The providers have associated project types and financing ranges listed.  This list consists of many of the big national PACE lenders. Slipstream has worked with most of them and views this list as quite robust.

I do not know of any directories.

This outfit, Generate Capital

https://generatecapital.com/

put over $180,000,000 into Hillsborough County Schools.  Tampa, Florida

For energy efficient light bulbs, when they took over the assets of Minimise USA LLC

https://minimiseglobal.com/

Minimise started the school project and I used to work there doing energy modeling of schools.

Minimise does investing in school projects.

Hope this helps, and maybe one of these companies can offer help.

I normally don't deal with these kinds of activities.  However, I am pretty sure that each state has an agency that looks for assistance from private entities in terms of energy efficiency type projects.  I would suggest contacting each state to find out about such entities in their state.