Special Bd. of Aldermen — 08/06/2019 Page 17
Mr. Hasselbeck Yes is the answer which is kind of an ancillary benefit to solar rays because you are right, these
things are designed to suck up solar energy. We have done some really neat studies especially over these past
few weeks where it has been so hot in taking our flare guns and measuring temperatures of the solar panels
versus temperatures of the roof surface underneath. UV rays and heat are two of the biggest factors in roof
wear and tear. So they are much cooler which reduces cooling costs. What we can’t do is quantify exactly how
much cooling load we are going to reduce. So because we can’t quantify it with 100% certainty, we don’t
include that in any of our models. But the benefit is there, it is real. We can show you differences in
temperatures and thermal imaging, but | can’t say this will also save the City X thousands of dollars in cooling
costs.
Alderman Lopez
And just my final question is you had, in discussion with Alderman Dowd, you said other climates have a higher
level of, your implication | think was that there is a higher level of sunlight?
Mr. Hasselbeck Yes it is something we call irradiance levels. So irradiance is the measure of watts per meter
squared but we are not in a terrible spot. The best predictor of solar production is your latitude lines, right? So
your latitude line is a really good predictor so you see down by the equator, that same solar panel will generate
roughly 30% more energy than it will up here in New Hampshire. But here in New Hampshire they still do pretty
good and if you follow the latitude line straight east to Germany; Germany has one of the largest solar markets
in the world and they are able to meet what? Was it 50% plus?
Mr. Weeks On peak, sunny windy days the entire German Economy, the 4" largest economy in the world is
virtually 100% solar and wind powered. They actually have 30% less solar insulation or irradiance than we do
here in New Hampshire at a higher latitude and yet they’ve been able to achieve that substantial benchmark
with a couple decades head start over this region.
Alderman Lopez
So we do OK but basically what you are saying that compared to equatorial regions, New Hampshire is not as
bright?
Mr. Weeks That is true as my wife bemoans often but nonetheless a lot of solar output.
Mr. Hasselbeck Bright enough.
President Wilshire
Commissioner do you have questions?
Fire Commissioner Paul Garant
| have one question and it may be more esthetics than technical but when | saw the inverters, the slide with the
inverters — one | wanted to know are they all mounted externally or are some mounted internally?
