3 phase project - when do I need to procure Green Power?

Hey Ted, There is some flexibility reagrding the purchase date. Since the REC purchase is not tied to the actual use, as long as the two year period covers a phase or phases of operation you should be fine. So either of your scenarios, or somewhere in between, should work. Yes you will need to have a signed contract in place to confirm the REC purchase.

Marcus, I agree with your line of thought, but why then is this credit deginated as a 'construction" phase credit on the detailed LEED checklist? I understand that Green Power is often decided on late in the project, but since it is based on design phase credit data and the energy model, It seems like this credit could be indicated as "D / C" (design/construction) ala ID credits to encourge more proactive thinking by the design team about Geen Power. Just my two cents.

Yes, that is an error. It is a design credit based on being hard-linked to EAc1 and EAc2. The error hasn't been fixed because no one at the USGBC understands why it is construction and not design. The USGBC claims it originated with the EA TAG, but that is not correct. This is became a construction credit because that was the consulting firm defined it in the first LEED Reference Guides. They were using it as a General Contractor Penalty/Credit Option for their personal LEED projects. Not the best reason, but tha has been cast-in-stone for more than 10 years now.

One potential reason to separate the EAp2 and EAc6 submissions would be having certainty in your green power purchase. Since the purchase is based on the final EAp2 results, reviewing them in the same phase might be problematic if your electric use in the Proposed model changes. Just my speculation as to the reason they are designated the way they are. I agree with you John that a D/C designation makes sense for this credit.

The reason I provided was as stated to me by the consultant responsible for designating EAc6 as a construction credit. The designation was not made by USGBC staff. About six years ago, I tried getting the USGBC to change the credit to D/C to no avail. What surprised me was, the USGBC person who I asked said they had to first speak with the consultant about the reason EAc6 was a C credit. That consultant defended their basis, and C it remained. It makes no sense for EAc6 to be a C credit. Owners make a commitment to install expensive renewable systems for EAc2 as part of the design. EAc6 really needs to be a D credit because it is hard-linked to EAc1 and EAc2. Project teams can turn it into a C credit by simply deferring it.

WIth the number of comments I see on energy models... I'm glad it's a construction phase credit. I want to know exactly how much I need to purchase. Otherwise I'd always get the credit marked "pending" whenever I get energy model comments. Granted I could just defer it.

The reason green power is a construction credit is that the developers of the first LEED Reference Guide, who were also LEED consultants, used it as a specification penalty/credit-option for contractors. They designated the credit as a construction submittal to reflect how they were managing their LEED projects. Since green power is linked with energy use and renewable energy it should have been a design credit from day one. Another construction credit, that should be a design credit, is heat island effect - non-roof. Site finish selection is entirely in a landscape architect's control. The original reference guide authors required GCs to provide reflectivity test data for finish samples of site hardscape finishes. That type of data was typically not available in 2000.