When the wind blows from east to west in the Gobi Desert singing can heard as the grains of sand vibrate together with a layer of silica to make a deep hum. The desert – a vast expanse in northern China and southern Mongolia – is known for its breath-taking dunes, mountains, and rare animals, such as snow leopards and Bactrian camels. 1,580 metres above sea level, spanning across 1,295 million square metres on land, the Gobi Desert is also home to the Gansu Wind Farm: the largest wind farm in existence. “With a planned capacity of 20GW, it’s the world’s largest wind farm in the world” (Nesfircroft). The project, worth a reported 17.5 billion USD, “will be home to 7,000 turbines and will produce enough energy to power a small country” (Nesfircroft). Thanks to the increased introduction of renewable energies, CO2 emissions have been massively reduced over recent years, but the existing carbon content in the atmosphere is too high to avoid catastrophic climate change. The latest IPCC report warns that limiting global warming to 1.5 degrees by 2100 will require “large-scale deployment of carbon dioxide removal measures” – beyond the increase of renewable energy (BBC).
Carbon capture is the process of capturing carbon dioxide before it enters the atmosphere. This can be done through a variety of methods; Carbon Engineering’s system uses a fan to drag air (containing 0.04% CO2) across a filter soaked in a potassium hydroxide solution. The filter then absorbs CO2 from the fanned air, which then flows to a second chamber where the liquid is mixed with calcium hydroxide (builder’s lime). The calcium hydroxide, lime, then adopts the dissolved CO2, releasing flakes of limestone. Once sieved off, the flakes are heated in a third chamber until they decompose, releasing pure carbon dioxide, which is captured and stored. At each stage of this process the chemicals employed for the process are recycled back into the process, thus creating a closed reaction that repeats endlessly without the need for waste materials (BBC).
aware_ presents 3 leading carbon capture companies on a mission to save the planet:
Carbfix – Turning Carbon Capture into Stone
Carbfix is one the leading companies in carbon capture, operating as a single company since 2020 from Iceland. Revolutionary in its field, their pilot project enabled the process of turning carbon capture into stone within a matter of years, a process that was previously thought to take centuries (MindsetCo).
Once the carbon is captured at the source of the emitter, it is dissolved in water where it interacts “with reactive rock formations, such as basalts – highly reactive rocks – to form stable minerals providing a permanent and safe carbon sink” (Carbfix). The CO2 dissolved in water is then injected into the ground, where it creates reactive rock formations of basalt. In essence, the process developed by Carbix imitates and accelerates the natural process of storing carbon in rocks. Favourable rocks, water, and a source of carbon dioxide are required to successfully transform the carbon capture into stone.
Climeworks – Carbon Capture Directly from the Air
Climeworks captures carbon directly from passing winds. Their highly technical system successfully captures carbon in a two-step process. Firstly, using a fan the air is drawn into the collector. Captured upon a “highly selective” filter material the carbon dioxide is then captured on the surface. After this, the captured carbon dioxide is locked in a heated to a temperature between 80 and 100 degrees, which leads to a “high-purity, high-concentration carbon dioxide” (Climeworks).
This carbon capture is then recycled, used a raw material or removed from the air through safe storage. In addition to their unique modular design that can be stacked to build machines of any size, their direct capture machines are powered solely by renewable energy.
“The grey emissions of our machines are below 10%, which means that out of 100 tons of carbon dioxide that are captured from the air, at least 90 tons are permanently removed and only up to 10 tons are re-emitted.”
Net Power – Carbon Capture to Create Clean Energy
The clean energy company Net Power has developed a four-step process to use carbon capture to generate advanced clean energy. Through burning natural gas with pure oxygen, the resulting captured CO2 is recycled “through the combustor, turbine, heat exchanger, and compressor, creating lower-cost power with zero emissions” (Net Power).
The first step is the process of burning natural gas with pure oxygen (instead of air). Pure oxygen leads to less fuel consumption and the flame temperature can be increased, leading to higher levels of efficiency. The resulting carbon capture is subsequently led to a heat exchanger, water is then removed and “pumped back into high-pressure”. After this, the high-pressure CO2 is reheated and recycled. Finally, the surplus CO2 from step 2 is captured and prevented from entering the atmosphere.
“The resulting CO2 is recycled through the combustor, turbine, heat exchanger, and compressor, creating lower-cost power with zero emissions.
Captured CO2 is pipeline ready and can either be cheaply sequestered or sold to industries such as the medical, agricultural, and industrial sectors.”
– Net Power
– By Kim N. Fischer
In October 1973, Saudi Arabia announced an oil embargo, targeting countries which had supported Israel during the Yom Kippur War – Canada, the UK and the USA were amongst the nations listed. By March 1974, oil prices had increased by almost 300%. Builders in North America, an area specifically targeted by the embargo, were tasked with building homes that used very little to no energy at all. Specific techniques developed in reaction to the shortages, such as using the sun’s rays as a direct heat source, later sparked a conversation between Bo Adamson and Wolfgang Feist, the early founders of the Passivhaus (Passive House) concept. Their original findings, with financial support from the German state of Hessen, lay the foundations for a concept that would inspire environmentally-conscious architects across the globe.
OPAL – the architecture firm established in Maine in 2008 – is unique amongst its peers, working exclusively with Passive House design principles. Based in Belfast, on the coast of Maine, OPAL continuously strives to achieve the highest standards of building performance and prioritises occupant comfort and well-being. The image below shows a room in Alnoba, is a mixed use gathering space in New Hampshire, and built exclusively with Passive House standards.
aware_ sat down with executive partner, Matthew O’Malia, to learn more about the Passive Design process.
aware_: Why does OPAL choose to incorporate Passive House standards in its practice?
OPAL: We have made the choice to build all of our projects to the passive house standard, because we feel that is the only responsible response to global climate change. Buildings account for nearly 40 percent of global energy use, and for an equivalent amount of carbon emissions worldwide. At OPAL, we understand that stemming climate change will require a massive reduction in the energy consumed by the buildings we design and construct.
Standard construction practices have improved energy efficiency in recent years, but we need to pick up the pace. World population is on track to grow from 7 billion today to 9 billion in 2050—all of us sharing the same finite resources, most living and working in buildings, and everyone wanting to be comfortable. To accomplish that while addressing the climate crisis, we’ll need buildings that use dramatically less energy—or none at all. And because the buildings we create today will be in service long after 2050, we’ll have to start building that way now.
aware_: Are there particular challenges OPAL has been presented with when working with Passive House standards?
OPAL: Passive house does require increased building performance, and the know how to do that, but in general, we find that it is no different than solving any other problem in our discipline, including fire or life safety, building code, etc. There have been several projects where unique planning and design were required to meet the passive house standard, including building the first certified Lab in the US for the University of Chicago, or building a masonry fireplace and full commercial kitchen in Alnoba. The key is to work at a detailed level and solve the problems based on how energy flows in a building- all of this can be modeled.
The New York architectural firm Ibañez de Sendadiano/Rouhe Architecture introduces Watershed House: a sustainable single family house prototype built to Passive House design standards in New York. The site, which lies in the NYC watershed, is a long, signal rectangular structure, sitting nestled in the woods. The prototype sits on a platform to both minimize disruption to surrounding woodland and allow views of the forest.
“The house is supported by seven steel piers and the partially below ground concrete mechanical room. Five main steel beams support the house and the two cantilevered decks which run the length of the house.
The house is built to be well insulated and airtight. The number of penetrations is limited and are taped to be airtight.”
aware_ sat down with Todd Rouhe, one of the co-founders of IdS/R, to find out more about the limitations and opportunities that exist when working with Passive House standards.
aware_: Are there elements of a Passive House design that are particularly intriguing to IdS/R?
IdS/R: The fundamental nature of enclosure in intriguing. Enclosure is fundamental to architecture. We are interested in the performance and geometry of the dwelling envelope.
We also appreciate the need for efficiency of design and resources required in Passive House design.
aware_: Are there limitations that arise when working with Passive House design? For example, do they limit artistic vision to any extent?
IdS/R: There are limitations with any building system. One of the enjoyable aspects of architecture is working with and responding to the rules that a system brings with it.
This could be a social system or guidelines for efficient building.
aware_: Is Passive House the future?
IdS/R: Passive House design is PART of the future. Interestingly, Passive House is not a new idea…but then again lots things that will be part of the future of construction are not necessarily modern concepts.
(Header Image by Eric Petschek for IdS/R architecture)
– By Eliza Edwards
Geothermal energy refers to the thermal energy stored in the accessible part of the earth’s crust and its utilization for heating purposes or electricity generation.
When it comes to renewable energy, we often talk about wind or solar power. An energy resource that is often forgotten or even criticized is geothermal energy. Yet, power and heat generation from geothermal energy, together with other renewable energies, represents an environmentally and climate-friendly alternative to fossil energy, which already avoids greenhouse gas emissions today and will be an essential source for a greenhouse gas-neutral heat supply in the future (Umweltbundesamt). In the earth’s crust, which is on average 30 kilometers thick under continents, the temperature increases by about 3 degrees Celsius per 100 meters (bmwi). The temperature in the liquid outer core of our planet is over 5,000 degrees Celsius. This energy stored in the form of heat beneath the surface of the solid earth is known as geothermal energy. Since this heat is always radiated uniformly in the earth’s interior, its energetic potential is ideal for heating or generating electricity (EEK.SH).
Power and heat generation from geothermal energy, together with other renewable energies, represents an environmentally and climate-friendly alternative to fossil energy, which already avoids greenhouse gas emissions today and will be an essential source for a greenhouse gas-neutral heat supply in the future.
Geothermal energy can be used for heating, cooling and power generation. In Germany, the temperature in the earth’s crust rises by an average of 3 Kelvin per 100 meters; accordingly, near-surface and deep geothermal areas tap different temperature levels (Umweltbundesamt).
Near-surface geothermal energy
Near-surface geothermal energy is the use of geothermal energy from depths of up to 400 meters. Due to the still relatively low temperature, this geothermal heat is usually raised to a usable temperature level with the help of heat pumps, geothermal probes, geothermal collectors or shallow groundwater wells. This form of geothermal use is possible for single-family homes, road construction and subway railroads, as well as for larger commercial or office complexes, e.g. with well galleries or geothermal probe fields. In addition to the use for heating purposes, these near-surface geothermal sources can also be used as a source for cooling purposes in the summer. Across Germany, there are now over four hundred thousand systems for the use of near-surface geothermal energy, with around 20,000 new systems installed every year (Umweltbundesamt; Erdwerk; Lexikon der Nachhaltigkeit).
Deep geothermal energy
Deep geothermal energy operates on a different scale than near-surface geothermal energy: Not only are heat reservoirs tapped at greater depths, with boreholes drilled to depths of up to five kilometers, but the plants operated with them are also much larger and more powerful. In this way, heating networks and entire city districts can be supplied with heating energy. If the temperature level is high enough, a geothermal power plant can also generate electricity (Umweltbundesamt).
The example of Iceland shows how geothermal energy can be used in an environmentally friendly and cost-effective way: More than 30 active volcanoes, plus geysers and hot springs, are visible signs of Iceland’s enormous geothermal potential. 90 percent of all households can be supplied with heat via hot steam, 25 percent of the country’s electricity can be generated with geothermal energy, and 66 percent of all energy consumed in the country can be generated by geothermal energy. In this way, Iceland aims to make itself independent of fossil fuels and imports in its energy supply (planet wissen; Greenpeace).
In Germany, the precondition for heating with geothermal energy is a well-insulated building. The investment costs are comparatively high, between 10,000 and 25,000 euros depending on the complexity, but apart from low maintenance costs and drive power for the heat pump, all running costs can be cut. Heating with geothermal energy amortizes the cost of fossil fuels in eight to twelve years. The average operating costs, including maintenance and electricity requirements, are about thirty percent of comparable gas or oil heating systems – keeping in mind the price increases of fossil fuels in the future (Kesselheld). In addition, geothermal plants for electricity generation are subsidized by the German government through the Renewable Energy Sources Act and the market incentive program (bmwi).
Other advantages are that geothermal energy guarantees an environmentally friendly, seasonal and weather-independent supply of energy inexhaustible and at any time. The area required by a geothermal power plant or heating center is comparatively small and thus space-saving for the end user, as well as being price-stable, safe and odorless. For the municipality, the independence from conventional energy sources, the creation of an affordable and price-stable heat supply through funding opportunities, the increase in local attractiveness and the fulfillment of environmental protection goals are significant advantages (Erdwerk).
Of course, there are also disadvantages, such as the risk of local earthquakes, if the temperature level required for the respective purpose is only given in deeper layers of the earth and deep boreholes into the earth’s interior are necessary. Also criticized is the insertion of heat probes or surface collectors into the ground, which requires a relatively large amount of space that is often not available (Lexikon der Nachhaltigkeit).
However, deep geothermal energy in particular can make a contribution to sustainable energy supply at present and in the future. Environmental effects are locally limited and technically controllable. It represents an inexhaustible energy source by human standards, which, with the right technology, could represent a revolutionary alternative to renewable energies in the future.
by Marie Klimczak