Companies are tapping into cities' underground networks of steam pipes as a source of clean energy.
"Green steam," as it's called, "recaptures and reuses thermal energy previously lost to the environment, utilizing advanced cogeneration technology," according to Paris-based Veolia, which operates a dozen of these networks in North American cities including Boston, Philadelphia, Baltimore and Montreal.
District energy, piping steam or water to a circuit of buildings for heating and cooling, is already widely used in many cities, according to National Geographic. There are more than 700 of these subterranean systems in the U.S. alone. But the source of that energy has often come from coal- or oil-fired power plants. "Now many old systems are getting retrofits to deliver green steam generated with cleaner fuels and recovered waste heat," National Geographic explained.
Take Veolia. They spent $112 million to upgrade the gas-fired Kendall Station power plant in Cambridge, Massachusetts in 2013. The plant captures waste heat that was going into the Charles River and instead funnels it into a 7,000-foot pipeline to heat and cool buildings in Boston and Cambridge. According to the company, 70 percent of Boston’s high-rise buildings are served by the green steam.
The company claims their green steam system has reduced the region's annual greenhouse gas emissions by 475,000 tons, the equivalent of taking 80,000 cars off the road every year.
“These legacy urban networks that were built back in the day by the utilities have become, fundamentally, portals for sustainable energy,” Bill DiCroce, who leads commercial and municipal business for Veolia, told National Geographic.
How cities, incl Boston use “green steam” to heat buildings & reduce emissions https://t.co/QWFWDEPLnw via @NatGeo https://t.co/8CyE8T117o— Barr Foundation (@Barr Foundation)1455037189.0
Other systems "use tree trimmings, household waste and other biomass to generate electricity, capturing the surplus heat in the process and delivering it to customers," National Geographic explained.
For businesses, it often makes economical sense to tap into this energy source. “It’s a lot cheaper” to buy energy from that system “than it is for me to actually have to maintain a piece of equipment that would heat enough water or steam to keep these buildings going,” Chris Sherman, Boston's Faneuil Hall marketplace operations manager, said.
In Minnesota, District Energy St. Paul, which heats 80 percent of buildings in downtown St. Paul, is greening its operations too. In October 2015, they announced plans to end the use of coal by 2021. They said this will reduce carbon dioxide emissions by 27 percent or 21,000 tons. They already utilize renewable energy sources, such as waste heat from biomass-fired combined heat and power and North America’s largest solar hot water system, but plan to increase their renewable sources as they phase out coal completely.
And using district energy to increase energy efficiency and renewables is even more popular outside of North America. A UN report last year identified 45 "champion cities," such as Copenhagen, Oslo and Tokyo, which used district energy to cut primary energy use 30 to 50 percent.
Copenhagen stood out in particular. Ninety-eight percent of the city’s buildings utilize district energy, and the city is working on converting all remaining coal-fired combined heat and power systems to biomass, according to the International District Energy Association.
Rob Thornton, president and CEO of the International District Energy Association, told National Geographic that cooling projects are getting “dramatic investment” in the Middle East, while Denmark and other countries are integrating solar farms to heat water for distribution.
There have been issues with leaks and explosions in some cities, but Veolia said they're rare. Some utilities, such as District Energy St. Paul, converted their systems to water to avoid the problems of steam explosions.
Still, "district energy has been slower to take off in North America because it’s driven mainly by private investment," Pernille Overbye, managing director of Canadian district energy at Ramboll, told National Geographic. But that may be changing. The U.S. Department of Energy has started supporting more district energy with a technical assistance program and possible loan guarantees.
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Though made in large part of plastic, glass, ceramics, gold and copper, they also contain critical resources. The gallium used for LEDs and the camera flash, the tantalum in capacitors and indium that powers the display were all pulled from the ground — at a price for nature and people.
"Mining raw materials is always problematic, both with regard to human rights and ecology," said Melanie Müller, raw materials expert of the German think tank SWP. "Their production process is pretty toxic."
The gallium and indium in many phones comes from China or South Korea, the tantalum from the Democratic Republic of Congo or Rwanda. All in, such materials comprise less than ten grams of a phone's weight. But these grams finance an international mining industry that causes radioactive earth dumps, poisoned groundwater and Indigenous population displacement.
Environmental Damage: 'Nature Has Been Overexploited'
The problem is that modern technologies don't work without what are known as critical raw materials. Collectively, solar panels, drones, 3D printers and smartphone contain as many as 30 of these different elements sourced from around the globe. A prime example is lithium from Chile, which is essential in the manufacture of batteries for electric vehicles.
"No one, not even within the industry, would deny that mining lithium causes enormous environmental damage," Müller explained, in reference to the artificial lakes companies create when flushing the metal out of underground brine reservoirs. "The process uses vast amounts of water, so you end up with these huge flooded areas where the lithium settles."
This means of extraction results in the destruction and contamination of the natural water system. Unique plants and animals lose access to groundwater and watering holes. There have also been reports of freshwater becoming salinated due to extensive acidic waste water during lithium mining.
But lithium is not the only raw material that causes damage. Securing just one ton of rare earth elements produces 2,000 tons of toxic waste, and has devastated large regions of China, said Günther Hilpert, head of the Asia Research Division of the German think tank SWP.
He says companies there have adopted a process of spraying acid over the mining areas in order to separate the rare earths from other ores, and that mined areas are often abandoned after excavation.
"They are no longer viable for agricultural use," Hilpert said. "Nature has been overexploited."
China is not the only country with low environmental mining standards and poor resource governance. In Madagascar, for example, a thriving illegal gem and metal mining sector has been linked to rainforest depletion and destruction of natural lemur habitats.
States like Madagascar, Rwanda and the DRC score poorly on the Environmental Performance Index that ranks 180 countries for their effort on factors including conservation, air quality, waste management and emissions. Environmentalists are therefore particularly concerned that these countries are mining highly toxic materials like beryllium, tantalum and cobalt.
But it is not only nature that suffers from the extraction of high-demand critical raw materials.
"It is a dirty, toxic, partly radioactive industry," Hilpert said. "China, for example, has never really cared about human rights when it comes to achieving production targets."
Dirty, Toxic, Radioactive: Working in the Mining Sector
One of the most extreme examples is Baotou, a Chinese city in Inner Mongolia, where rare earth mining poisoned surrounding farms and nearby villages, causing thousands of people to leave the area.
In 2012, The Guardian described a toxic lake created in conjunction with rare earth mining as "a murky expanse of water, in which no fish or algae can survive. The shore is coated with a black crust, so thick you can walk on it. Into this huge, 10 sq km tailings pond nearby factories discharge water loaded with chemicals used to process the 17 most sought after minerals in the world."
Local residents reported health issues including aching legs, diabetes, osteoporosis and chest problems, The Guardian wrote.
South Africa has also been held up for turning a blind eye to the health impacts of mining.
"The platinum sector in South Africa has been criticized for performing very poorly on human rights — even within the raw materials sector," Müller said.
In 2012, security forces killed 34 miners who had been protesting poor working conditions and low wages at a mine owned by the British company Lonmin. What became known as the "Marikana massacre" triggered several spontaneous strikes across the country's mining sector.
Müller says miners can still face exposure to acid drainage — a frequent byproduct of platinum mining — that can cause chemical burns and severe lung damage. Though this can be prevented by a careful waste system.
Some progress was made in 2016 when the South African government announced plans to make mining companies pay $800 million (€679 million) for recycling acid mine water. But they didn't all comply. In 2020, activists sued Australian-owned mining company Mintails and the government to cover the cost of environmental cleanup.
Another massive issue around mining is water consumption. Since the extraction of critical raw materials is very water intensive, drought prone countries such as South Africa, have witnessed an increase in conflicts over supply.
For years, industry, government and the South African public debated – without a clear agreement – whether companies should get privileged access to water and how much the population may suffer from shortages.
Mining in Brazil: Replacing Nature, People, Land Rights
Beyond the direct health and environmental impact of mining toxic substances, quarrying critical raw materials destroys livelihoods, as developments in Brazil demonstrate.
"Brazil is the major worldwide niobium producer and reserves in [the state of] Minas Gerais would last more than 200 years [at the current rate of demand]," said Juliana Siqueira-Gay, environmental engineer and Ph.D. student at the University of São Paulo.
While the overall number of niobium mining requests is stagnating, the share of claims for Indigenous land has skyrocketed from 3 to 36 percent within one year. If granted, 23 percent of the Amazon forest and the homeland of 222 Indigenous groups could fall victim to deforestation in the name of mining, a study by Siqueira-Gay finds.
In early 2020, Brazilian President Jair Bolsonaro signed a bill which would allow corporations to develop areas populated by Indigenous communities in the future. The law has not yet entered into force, but "this policy could have long-lasting negative effects on Brazil's socio-biodiversity," said Siqueira-Gay.
One example are the niobium reserves in Seis Lagos, in Brazil's northeast, which could be quarried to build electrolytic capacitors for smartphones.
"They overlap the Balaio Indigenous land and it would cause major impacts in Indigenous communities by clearing forests responsible for providing food, raw materials and regulating the local climate," Siqueira-Gay explained.
She says scientific good practice guidelines offer a blueprint for sustainable mining that adheres to human rights and protects forests. Quarries in South America — and especially Brazil — funded by multilaterial banks like the International Finance Corporation of the World Bank Group have to follow these guidelines, Siqueira-Gay said.
They force companies to develop sustainable water supply, minimize acid exposure and re-vegetate mined surfaces. "First, negative impacts must be avoided, then minimized and at last compensated — not the other way around."
Reposted with permission from DW.