HomeDiagramsDatabaseMapsForum About

Go Back   SkyscraperPage Forum > Discussion Forums > Engineering


Thread Tools Display Modes
Old Posted Jun 12, 2021, 7:18 PM
M II A II R II K's Avatar
M II A II R II K M II A II R II K is online now
Registered User
Join Date: Aug 2002
Location: Toronto
Posts: 51,134
Boise Is Tapping Into Free, Sustainable Energy - and Other Cities Could Follow Suit

Boise Is Tapping Into Free, Sustainable Energy - and Other Cities Could Follow Suit

June 3, 2021

By Shiva Nagaraj

Read More: https://nextcity.org/daily/entry/boi...s-could-follow


When Boise first installed its downtown heating system nearly four decades ago, “it was a pilot project,” Jon Gunnerson, the city’s geothermal coordinator, tells Next City. “Nobody knew how successful it was going to be.” Today, it is the most prominent and successful example of geothermal district heating in the country. “We’re heating the big buildings downtown, and we see a huge benefit of offsetting the energy that these large buildings would use,” Gunnerson says.

- Geothermal energy harnesses the heat stored in rocks underneath the Earth’s surface. The Earth’s inner core is about 10000 degrees Fahrenheit, about as hot as the surface of the Sun, but even a few miles below the surface, temperatures can soar to well above 200 F. A fraction of this heat would be enough to satisfy the world’s energy needs. Although other renewable sources of energy, like wind and solar, have garnered more attention, geothermal energy has an important advantage over them. While solar and wind energy ebb and flow with the conditions, the Earth’s heat doesn’t fluctuate. “It’s always on, always available. It’s a 24/7 resource,” says Amanda Kolker, a geothermal geologist at the National Renewable Energy Laboratory. — Although geothermal energy can be used to generate electricity, Kolker says that it holds more promise for “direct use,” especially district heating. Geothermal electric plants require extremely high temperatures, but district heating systems like Boise’s need only what the geothermal industry calls “low temperature” heat, which is anything below about 300 F. “The distance to [these temperatures], it’s not far; we’re talking a couple of miles deep,” says Gunnerson.

- Boise, for example, has dug three wells, ranging from 400 to 800 feet in depth, to capture water from the aquifer. The water, which has been heated by radioactive rock decay in foothills northeast of the city, is approximately 175 F. Once the water flows through the wells, it is piped to the downtown area, and the buildings connected to the heating system extract about 50 degrees F of heat from the water. Afterwards, the water is injected back into the aquifer, where it is reheated and can later be collected again. — “One thing that always surprises people who come and take a look at our system is the simplicity of it,” Gunnerson says. “Our geothermal program isn’t much more than a sophisticated irrigation system. We just have a small well, and we’ve got a small pump on it. It doesn’t take much energy. It pumps the water out of the ground and runs it through a network of pipes. And we have another pump that’s a little bit larger that injects this water back into the aquifer.” Boise’s system is entirely renewable. It requires no fossil fuels, and because the water is constantly recycled in the aquifer, the system sustains itself.

- It is also relatively cheap to operate. Gunnerson says that his annual budget to heat all the buildings is about $750,000. Boise can also connect more buildings without much added cost. “We’re limiting carbon emissions, we’re providing a sustainable energy, long-term,” Gunnerson says. “We’re also providing local energy, something that doesn’t have to be outsourced from overseas or a long-distance away.” — That’s not to say that it was simple for Boise to install its heating system in the 1980s. At the time, the downtown area had already been developed, so the city had to open up streets and lay down new pipelines to connect buildings to the new heating system. But Gunnerson says that the Boise community was “supportive” of the initiative. — Geothermal district heating could play an important role in the nation’s transition to clean energy. Heating and cooling for commercial and residential buildings accounts for approximately a quarter of all energy consumption in the United States. Much of this energy currently comes from fossil fuels like natural gas, fuel oil, kerosene, or propane. — Currently, there are only 23 geothermal district heating systems in America. These existing systems depend on “hydrothermal” sources, which are naturally occurring sources of hot water below the Earth’s surface that are easily accessible, as in Boise.

- Another technology is called a “closed loop,” in which a fluid is injected into a pipe or wellbore that travels deep underneath the ground. Unlike with EGS, the fluid never comes into contact with hot rocks. Instead, as the water moves underneath the surface, it absorbs the heat from the rocks. “I think the technologies are going to start proving themselves so that we can harness this geothermal energy anywhere,” says Gunnerson. — If these technologies can be successfully deployed, Boise may no longer be the lone example of urban geothermal district heating. Based on the confluence of heating demand and the availability of geothermal resources, the Department of Energy’s data suggests that district heating could be viable by 2050 in several major urban and suburban areas, including Chicago, Boston, Houston, Los Angeles, Dallas, New York, and Philadelphia. “I do think the big cities are where it needs to be targeted,” says Gunnerson. “You get more bang for your buck to heat a downtown, high density, high population area.”


Reply With Quote
Old Posted Nov 8, 2021, 9:03 PM
TheObsidianOrder TheObsidianOrder is offline
Registered User
Join Date: Nov 2016
Location: Boise,ID
Posts: 5
My god, the use of such an old pic of downtown Boise is blasphemy lol!!
Reply With Quote
Old Posted Nov 12, 2021, 11:51 AM
Lariliss Lariliss is offline
Registered User
Join Date: Nov 2021
Posts: 7
Thank you for sharing.
In my opinion, this kind of information should be not only in dedicated magazines, but in forums as well.
Mainly, if we are all reconsidering the economics of energy and searching for the best practices, the local examples bring them closer from 'somewhere else' to 'look around for possibilities'.

Cities with a heavy industry, the pollutants, may reconsider wasted energy for hot water supply, for instance. Sounds easy, but the initial infrastructure might be updated.
Reply With Quote

Go Back   SkyscraperPage Forum > Discussion Forums > Engineering
Forum Jump

Thread Tools
Display Modes

Forum Jump

All times are GMT. The time now is 11:05 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2021, vBulletin Solutions, Inc.