CALMAC played an integral role in the energy storage system incorporated in the construction of the new headquarters for the California Lottery back in February 2010. The facility consists of a 155,000 square-foot, 6-story main structure and a 400-seat net zero energy pavilion, which is used for staff meetings, training classes and lottery commission meetings. The $61 million facility incorporates multiple sustainable features, including ice-based thermal energy storage, green roofs, daylight harvesting, a photovoltaic system, window glazing and automated window coverings — all of which reduce operating costs, improve energy efficiency and reduce the structure’s carbon footprint.
CALMAC’s IceBank® energy storage tanks were installed to provide the main structure as well as the pavilion, with nearly 2,000 tons-hours of cooling capacity. How the thermal cooling system works: two 200-ton chillers create and store ice at night, using energy from the utility, when demand is low and energy prices are discounted. The ice is then melted the next day to cool occupants during peak demand hours, when energy prices are significantly higher. The pavilion has two air handlers totaling 57.5 tons, as well as 100 kW PV solar panels. Any energy allocated to the chiller and energy storage tanks for the pavilion is offset by the renewable energy generated by the solar panels, thus the pavilion can be classified as net zero.
In this interview, MacCracken talks about the driving concepts behind the California Lottery Building installation as well as emerging trends in the green building construction industry.
Q: The California Lottery Building case study illustrated the possibilities of effective energy storage technology (i.e., green cooling) in combination with multiple forms of renewable energy power generation. Do you see these applications as the wave of the future, or would you consider them as more “niche” applications?
A: I definitely see this as the wave of the future, just not necessarily connected in the same way as was done for the California Lottery Building. The storage does not necessarily have to be at the same location where you are collecting this energy.
Q: ‘Green building’ design clearly played a key role in the construction of the California Lottery Building project. In your opinion, what will it take for more facilities managers, architects, project managers, etc., to adopt this approach on a wider scale?
A: I think the green building movement is moving well and is going to continue to move forward. It is representative that there is now 3 billion square feet certified under LEED (Leadership in Energy & Environmental Design). Prior to LEED, there was very little motion in a more sustainable direction. Put another way, think of the construction industry as a gigantic ship that has been going in the wrong direction. I think we have begun turning that ship around, but it’s going to be a long process. The good news is there’s a lot of momentum.
Q: A major feature of the new design included the construction of a “net-zero” energy pavilion. For the pavilion to achieve net zero classification, it had to be designed to operate using no more energy than is provided by its own on-site generation. Can you elaborate?
A: Sure. One of the ways to think about this particular building is that we were defining net zero for certain parts of it. That being said, I think the definition of net zero needs to be clarified. Right now the definition is, ‘You don’t net-buy any electricity from the grid.’ But it doesn’t matter that you collect more at some times and you send it to the grid, as long as what you’ve taken back from the grid is not more than that. The problem with that is everybody might rely on the grid at the same time, so that when the clouds come over, they are going to have to draw from the grid.
Q: What role does energy storage play in this regard?
A: Solar buildings don’t necessarily reduce the peak demand of the building; they reduce the overall usage. That’s where you need storage, and it has to be an integral part. Here’s how I explain integral storage: Think of a green building that’s off the grid — there will be ways to collect the energy, but I guarantee you that there will be a lot of energy storage at that site. There will either be back-up fossil fuels at that site, there may be thermal (either hot or cool), and there will be batteries in order to support that site. Now, just because you take a couple of wires and now connect to the grid, your storage issues don’t magically go away (although that’s what a net zero building, by current definition, would suggest.
Note that the grid does not have any energy storage on it — that’s a misperception that’s out there that the grid is this magical thing that can give you power whenever you need it. Storage is going to have to be added to the building and to the grid in a big way for us to move in a more sustainable direction.
Q: What are some of the key challenges to moving ahead in that area?
A: In any energy conservation measures that you do, you certainly want to tackle the ‘low-hanging fruit’ first. I look at the low-hanging fruit this way: our energy problems, in most places, have to do with peak summer hot days. If you can store that energy for use on a hot summer day, you can reduce the demand on the grid dramatically.
Here’s an analogy: If you were going to throw a party, you would not start making ice cubes when people began walking through the door — your refrigerator would never be able to keep up with that. For a party, I figure you would need about one pound person. To air condition that same person when he/she goes to the office the next day, you would need the equivalent of 150–300 lbs of ice to keep that person comfortable during the day. Just as it’s ludicrous to wait to start making ice for the party, it’s 100 times more ludicrous to start drawing electricity when they arrive to work just to keep them cool. This practice has caused our problems with the grid.
So, the first thing we want to do is get rid of this ludicrous practice and begin storing cooling — which is exactly what we do. The cool storage is the most important aspect that you can add to the building.
The next thing you have to do is add storage to the grid side, because you do need electrons to run fans, lights, etc., but you don’t necessarily want those stored electrons to run [air conditioning] compressors to create cooling — that makes no sense. Also, you don’t want to add battery storage just to run the compressors, because that would be very expensive.
To read this interview in its entirety, look out for the forthcoming May/June issue of Renewable Energy Focus magazine. Subscribe online today!