By Gero Rueter
Heating with coal, oil and natural gas accounts for around a quarter of global greenhouse gas emissions. But that's something we can change, says Wolfgang Feist, founder of the Passive House Institute in the western German city of Darmstadt.
"Buildings can be powered in a climate-neutral way, and that's possible worldwide with renewable energies," he told DW, adding that a crucial factor is to make buildings more efficient so no energy is wasted.
"With good insulation and ventilation systems, it's possible to achieve energy savings — compared to conventional buildings — of 80-90% in new buildings and 75-80% through energy-efficient renovation in old buildings."
The remaining demand could then be met with a mix of renewable energies. And this combination can vary, depending on the region, says Feist, who is a professor of physics and a pioneer of efficient construction methods.
"I see district heating with renewable energies, and heating with ambient heat and heat pumps as important sources here," he says.
The use of wood or wooden pellets is another way of meeting the heating needs of individual buildings, Feist says, adding however that this is "not a sensible option" for entire cities or industries because it's not sustainable and would create excessive demand for biomass.
Germany's financial capital has big environmental plans.
Frankfurt Strives for Climate Neutrality
The German city of Frankfurt is aiming to become climate neutral by 2050. In order to reach that goal, the financial hub is relying on a range of technologies, says Paul Fay from the city's energy department, who is coordinating the transition. With help from scientists, the city has drawn up a master plan that includes passive houses and energy-efficient refurbishments on older structures.
Solar panels on the roofs of Frankfurt's buildings will generate some of the city's thermal energy. Another share will come from heating pipelines serving the city's districts, where warmth will be created by burning waste and wood, or through waste heat from data centers. Ambient energy from the ground can also be harnessed with the help of heat pumps.
How Does a Heat Pump Work?
In theory, a heat pump works like a refrigerator — within a closed, multistage system, heat is generated in a compressor, while cool air is created in an evaporator.
A liquid coolant extracts heat from the environment to warm buildings or water. The heat pump takes energy from the ground, groundwater or air.
Heat pumps need electricity as their operating energy, and how well they perform depends mainly on the heat source.
"We examined 60 heat pump systems in older buildings in Germany," says Marek Miara, a researcher at the Fraunhofer Institute for Solar Energy Systems (ISE) in Freiburg.
"Heat pumps in older buildings that use air as a heat source generate an average of around 3 kilowatt-hours of heat from 1 kilowatt of electricity. And heat pumps using groundwater and soil as heat sources generate on average 3.9 times as much heat," Miara told DW, adding that systems in new buildings are generally more efficient.
Growth in Key Technologies
Heat pumps are a core component of plans for climate-neutral energy and heating in the future, and the technology is increasingly replacing fossil fuel-powered heating systems around the world.
"We're seeing a very positive global trend," says Thomas Nowak from the lobby organization the European Heat Pump Association (EHPA). "We're experiencing a golden age for heat pumps, it's becoming a mass market."
According to an EHPA report, 18 million heat pumps were sold worldwide in 2018 — 1.3 million of them in Europe. Global sales are growing by 10% each year, the report said.
Heating With Less CO2
Heat pumps have proven extremely popular in Europe, especially in Scandinavian nations. Electricity in these countries is already generated mainly by climate-friendly wind and hydropower. According to calculations by Fraunhofer ISE, heat pump systems in Sweden generate 90% fewer carbon emissions than heating systems that rely on natural gas.
Many countries in the European Union and other parts of the world still get much of their electricity from coal and gas. But according to calculations by Fraunhofer researchers, heat pumps there would also be a more environmentally friendly option than heating with natural gas. Across the EU, using heat pumps would result in an average CO2 saving of around 60% compared to natural gas. In Germany, the saving would be around 30%, the Fraunhofer researchers say.
If electricity continues to become more climate friendly through the expansion of wind and solar power, as is currently the case in Germany, CO2 savings from heat pump systems will only keep growing. And if the pumps' operating power comes from 100% renewables, then this heating technology becomes climate neutral.
Heating Transformation Needs Policy
Energy and building experts agree that making the switch to climate-neutral heating in all buildings and industries worldwide is certainly possible.
The Swiss city of Schaffhausen is among the growing number of municipalities using heat pump technology.
Experts and environmentalists are calling for a ban on the installation of new polluting heating systems.
"However, there is still a need for more training," says Andreas Nordhoff, a consultant for passive house technology who also trains people in the construction industry. "Craftsmen, architects and building owners often lack knowledge about how everything can be optimally coordinated, and how much energy and money can be saved," he says.
Politics also has an important role to play in establishing a climate-friendly heat supply.
"What we need now is a ban on new oil heating systems. These are particularly harmful to the climate, so new installations should be prohibited from now on," says Nicolas Besser, project manager for energy and climate protection at the German environmental organization Deutsche Umwelthilfe (DUH).
"Natural gas heating systems are more climate friendly compared to oil heating, but they're still harmful. That's why we also need a ban on installing them from 2025," Besser says.
In order to reach climate targets set out in the Paris agreement, DUH is calling for an emergency climate protection program for buildings. They want to see funding put towards renovating structures, expanding municipal heating networks and accelerating the phaseout of oil and gas heating.
Reposted with permission from DW.
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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.