> Still can’t find a “smart fridge” that runs in ultra-chill mode when rates are cheap and backs off when they’re high. Kinda antithetical to use more electricity to save but it’s true.
A company called Ice Energy manufactures the Ice Bear, a unit designed to work alongside a traditional air conditioner. Like the large system used by Credit Suisse, the Ice Bear is designed to run indoors and at night, when temperatures and energy costs are lower. Ice Bear creates a block of ice at night that cools the refrigerant during the day, rather than running the refrigerant through a condenser (at peak hours) that requires a lot of energy.
Underneath the Jordan Quad Parking Lot at Stanford University, 360 miles of piping run through a four-million-gallon tank of water. At night, subzero ammonia -- a common refrigerant -- runs through the pipes, freezing the water into giant blocks of ice. The system, which is one of the largest of its kind in the United States, sends cold water from the melting ice throughout Stanford's campus, cooling buildings from noon to 6 p.m. When the facility was first built in the mid-1970s, it skipped the ice stage, instead directly cooling water that was piped through campus. A $22 million renovation -- completed in 1999 -- converted it to its present form, which saves the university a reported $500,000 a year on energy bills.
This is a great post. Thank you to share. How do you know so much about this Stanford University system?
> A $22 million renovation -- completed in 1999 -- converted it to its present form, which saves the university a reported $500,000 a year on energy bills.
So, it takes at least 44 years to repay? This sounds like a terrible investment. Normally, energy saving projects repay themselves in about 7-10 years. Also, this system sounds incredibly complex. What is the annual maintenance cost? Surely greater than zero.
I am aware of using phase change of water for various cooling purposes. Finding references again on them isn't difficult if you know what you're looking for.
Many years ago there was a green building series on KQED that featured such approaches.
Shifting when you are using energy is part of conservation.
As to how it works... it's a cubic rather than planar ice skating rink. You freeze a block of water at night, and then during the day, slowly melt it as you transfer waste heat from the building into it (rather than rejecting the waste heat with a compressor during peak energy use hours).
This is a major university, so they could be expected to be a little on the wild side with projects like that. If they're the only one with a system like that, it raises the cost.
Why? I would rather the university conserve spending to reduce cost of tuition. Instead department s of energy, for R and D, or companies flush with cash and wanting to virtue signal can splurge on such projects.
Different budgets can go to different things. Grants for X can't be spent on Y. An endowment may be for a specific goal and likewise can't be spent on some other things.
Stanford is a research institution - and some money that it receives will be going to research rather than trying to reduce enrollment costs.
Alternatively, "hey, they spent $22M on that project... maybe we should shut down the Stanford Liner Accelerator ( https://www-ssrl.slac.stanford.edu/lcls/budget.html ) which had a project cost of $315M."
There are many good institutions of higher learning out there that do not have research as part of their goal. There are 116 different community colleges within California that do not have research as part of their program and the California State University system (as opposed to University of California system) deemphasizes research. Stanford itself is a private school and not part of either of those systems.
On the other hand, people who go to Stanford often want to study under and participate in the research that is being done in a given field - and that implies that research is being done (and money is being spent on it).
Only if their energy cost never increases and the figure is resistant to inflation - 500k in 1999 is now equal to $942,584.03. There's also something to be said for the carbon emissions and the fact that we can point to frozen water being a viable system.
Thanks for this, I had never heard of qanats or wind towers.
I'm imagining a giant modern qanat running underneath a city or a large dense neighborhood and each structure reaching down into it to feed a ground-source heatpump in the cooler water like roots. Everything fed by solar panels on the roofs.
Because that's 22 million which could've bought rather a lot of solar panels and batteries, which would be more then adequate to run the system and much more transferrable in application.
Or you could invest it, make way more then 22 million over that timeframe and do even more.
Cost is a proxy for resource consumption, and in this case it seems like this was incredibly inefficient.
Edit: at current prices you build a 22 MW solar plant instead, for example.
> By creating ice when electrical rates are low and then “burning” it during the hottest part of the day, the Ice Plant saves Stanford roughly $500,000 per year and decreases Stanford’s peak electrical demand by 8 megawatts.
That's 8 MW ... you say 22 MW today, but in 1999 that 8 MW offset looks more like Solar Two ( https://www.nrel.gov/docs/legosti/fy97/22835.pdf ) which produced 10 MW and cost 58 million on 126 acres of space.
> In 2015, as part of the Stanford Energy Systems Innovations (SESI) program, a new Central Energy Facility (CEF) was built, and the cogeneration plant and ice plant were retired. SESI transformed the university energy supply from a 100% fossil-fuel-based combined heat and power plant to grid-sourced electricity and a more efficient electric heat recovery system, helping Stanford achieve 100% renewable electricity.
https://home.howstuffworks.com/green-living/ice-block-ac.htm
A company called Ice Energy manufactures the Ice Bear, a unit designed to work alongside a traditional air conditioner. Like the large system used by Credit Suisse, the Ice Bear is designed to run indoors and at night, when temperatures and energy costs are lower. Ice Bear creates a block of ice at night that cools the refrigerant during the day, rather than running the refrigerant through a condenser (at peak hours) that requires a lot of energy.
Underneath the Jordan Quad Parking Lot at Stanford University, 360 miles of piping run through a four-million-gallon tank of water. At night, subzero ammonia -- a common refrigerant -- runs through the pipes, freezing the water into giant blocks of ice. The system, which is one of the largest of its kind in the United States, sends cold water from the melting ice throughout Stanford's campus, cooling buildings from noon to 6 p.m. When the facility was first built in the mid-1970s, it skipped the ice stage, instead directly cooling water that was piped through campus. A $22 million renovation -- completed in 1999 -- converted it to its present form, which saves the university a reported $500,000 a year on energy bills.