Special Bd. of Aldermen — 08/06/2019 Page 14
Mr. Hasselbeck Excellent question. So during the term of the power purchase agreement, the owner of the
array pays for that. So in this case that would be an investor group that we’ve done and they would pay me and
my team to come out and do what we call an annual inspection. It is about a 20 page report of things that we
look at both mechanically and electrically to basically do preventative maintenance to maximize the up time and
longevity of this system. We are also on a daily basis, for systems like this, monitoring the production and we
have really excellent visibility into what is going on a per panel basis. So if there is an issue we are able to
identify it remotely and then make a determination if we need to roll a truck to fix it or if we can resolve it
remotely. So that is all handled by the owner of the PPA.
Alderman Dowd
Good answer to go along with a good question.
Mr. Weeks _ | will just note Alderman Dowd, also in the financials that we will get into in a moment we include an
optional O&M Contract were the City to elect upon entering into ownership of the array to continue having
ReVision provide that service. That is a totally optional expense but to be conservative in the numbers we are
assuming you are paying for that and so not having to think about the Operations & Maintenance in the future.
Alderman Dowd
Ok the other question | have is that there is a lot of technology going on, we've just alluded to a little bit. MIT is
doing a lot in the solar panel arrays. They are making them from different products now than they used to. You
need fewer panels now. | have no idea in having read these articles when that is going to happen. If we build a
new school we are 2 years away from a solar panel, minimum. So we don’t know how the technology may
change between then and now. But | know they are looking at like two face solar which uses the reflective light
that goes beyond the panel, gets it coming back. | don’t know if you’ve been involved in that at all?
Mr. Hasselbeck Yep very much so. So those are called, please stop me if | get into the weeds, this is my zone
right here. So those are called bifacial modules. And in some scenarios they make a ton of sense because
they allow us to harvest extra bits of solar energy and get more production. In these specific types of
installations, in the State of New Hampshire with our climate the additional energy that those panels produce do
not justify the additional cost of those panels. But that is specific to these buildings. Where we really like those
bifacial modules is on solar carport designs where now we have instead of maybe 6 to 12 inches between the
back of a panel and a roof surface, we have you know 10 to 12 feet in a nice reflective parking lot surface so we
can really harvest that extra energy. Ora large ground mounted array can be another good opportunity for
those bifacial modules.
Alderman Dowd
Right so and | noticed in the articles it said they like to do them on flat surfaces not angled roofs because of the
way it reflects. Also the other technology that is coming in is are panels that sort of follow the sun to some
degree to increase their efficiency.
Mr. Hasselbeck Another great question, so those are called trackers, they are solar tracking arrays and they
make them that track the access in one way like this and also dual access trackers so they will follow it north
and south and east to west. Those options are out there. In some cases they do make sense, not in these
