ASHRAE Journal - July 2021 - 28

ROUNDTABLE
have to start thinking about that in the future, and how
do we quantify the value of storage and other technologies
along those lines?
Torcellini: You are getting into the barriers of storage-let's
focus on this: Why doesn't everybody put
storage in buildings? What is preventing widespread
implementation?
MacCracken: It can be confusing. I cannot take an
energy modeling program right now and put in realtime
carbon, energy costs and energy metrics on a
storage system and optimize for minimum carbon or
optimize for minimum cost or optimize for minimum
energy. It is complex. And, if you're going to be selling
storage to people, it's got to be simple. It's got to be like
this: " Here's your building. These are the parameters
you're working with. This is what storage is going to
bring to you as a value. " It's pretty easy to understand
that, if you electrify a building and you use wind power
to run a compressor at night and store cooling, you can
cool that building carbon-free, right? It can be pretty
straightforward. But that's not easy to show now, and it's
got to be very easy to show.
Lowe: I think to pick up on what Mark is saying, the
other challenge is that for all the services and value
that storage provides, there are not always price signals.
I think that today storage is being deployed using
the only price signal available at the building level
today, which is the retail electrical rate design. That
really informs the cost-effectiveness and what is easily
able to be communicated to end users. I think having
such a flexible asset with a lot of value is hard to quantify
solely on financial terms-that is a real barrier to
wider-spread adoption.
Narayanamurthy: I would go back to something more
mundane, which are applications issues. I think thermal
storage is suffering from the energy density challenge.
I've been with many building developers who are like,
" Hey, I would rather put up a PV and power my heat
from a water heater, rather than having solar thermal, "
for example. But, solar thermal is more storage. People
are always challenged with, " Hey, where do I put my
storage tanks? " -especially as the construction industry
gets more infill buildings that are space constrained.
That is different in the large commercial space. When
we get into the smaller commercial and residential
spaces, those become more challenging, and I think
that's been a barrier to thermal storage. That's why
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you're seeing people stick a battery on the wall and just
go because it's one-size-fits-all. They don't have to think
about it. They don't have to worry about it. They don't
have to figure it out. And yeah. So I think that's something
that we see. Every builder we talk to, they're like,
" Yeah, hey, just give me a battery, and I'll put it in there, "
even though the battery is costing them $23,000 or
$25,000, and they could probably get thermal storage for
a fifth of the cost.
Torcellini: Ram, why are they investing in the battery?
One of the barriers is always cost, right? If it's not saving
energy, and it's hard to think about even time-of-day
differences of costs, why would people do it? But like you
said, people are putting batteries in. What's motivating
them?
Narayanamurthy: It's resilience. I think with the battery
they feel like they get better resilience. I think the
narrative has not been clear about how thermal storage
and electrical storage can work together to enhance your
resilience. I think that's an area that we should maybe
focus on, to Michael's point, but yeah, but they see battery
as resilience.
Torcellini: Give me the narrative.
Narayanamurthy: The narrative is, " Hey, I'm going to
put a big community solar system in anyway to meet my
code requirements or get tax credits or whatever. If I'm
going to put a big solar system in, I might as well just put
a battery in, which will help me with offsetting demand
rates, but also provide some resilience aspects and some
backup power. " So they see a battery as serving multiple
needs at the same time. The story line of thermal storage
is a little harder. As long as we keep talking about thermal
storage as an add-on to an existing HVAC system,
it makes that story much harder to sell. Whereas if we
had one integrated system that integrates building mass
storage with active thermal storage in HVAC systems,
and they all kind of just work together and seamlessly, it
might be an easier sell because that's what batteries do.
They can serve multiple needs, and the customer doesn't
have to think about it.
MacCracken: I think Ram makes an excellent point.
In the electrical battery-speak, they use the currency of
energy, right? It's electricity, and that currency can be
traded around, and it's used by most devices, and it's
just easier to think about. I think residential solar with
storage makes sense for the resiliency, but also, as we
were mentioning, a home with excess solar can use the
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ASHRAE Journal - July 2021

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