Ecoligna’s Spectralite: the future of Building
This article is part of a moonshot project carried out by Sakeenah Aderinto, Surya Maddula and Diyor Mukumov and the author. Learn more about Ecoligna here.
The building industry is one of the main economic sectors in the world. Its importance comes from the human need for shelter and the development of infrastructure in urban areas. In the United States, it accounts, for 4.2% of the total Gross Domestic Product, 7,5% of Canada’s GDP, and 9% of the European Union’s. Construction not only involves the buildings of homes (although residential construction is a great part of the sector), but also other types of infrastructure such as commercial buildings, roads, bridges, tunnels, airports, schools, hospitals, and other structures. It provides a high amount of revenue, a sign of economic recovery and growth.
It’s expected that in 2060 the global building floor will have doubled, meaning that more and more resources will need to be allocated and exploited around the world. Although these are positive predictions for the industry, we shall not forget how the environmental crisis will affect our climate and disposal of resources, apart from the changes of weather different regions of the world will face this and the following decades.
It’s time to rethink how we build and construct the cities of tomorrow.
You are pushing the boat out -through the window
We, consumers, are wasting energy. It’s just not the electronic devices that have to be always connected (the fridge, freezer, etc) or the vampire load consumption (this phenomenon explains how some appliances we leave charging are a wasteful habit due to the power drain from the house’s power grid). The choice of materials by the architect when designing a building can directly impact our energy bill when we take a look into how much do we spend on climatization. This deeply depends on which region you live in and when was your home built.
The U.S. Department of Energy estimates that is possible to save between $126 to $465 a year by replacing single-pane windows in your home. Windows are an important element that enables us to receive natural light saving the electricity needed to provide artificial light. However, there are some takebacks such as the transfer of heat that is mainly produced through them.
The energy used for heating and cooling buildings is heavily influenced by the energy efficiency of windows. In fact, windows are responsible for consuming 30% of the energy used for heating and cooling buildings in the US. This high energy consumption has an annual impact of 4.1 quadrillion BTUs of primary energy (US Department of Energy, 2006). The British Thermal Unit measures heat, a magnitude that in the International System is referred to as joule (J). Primary energy refers to the energy found in natural resources in its raw form before it’s transformed into other forms of usable energy (electricity, mechanical energy, etc) (Repsol, 2023).
Here’s there’s a graphic of unit equivalences.
Energy poverty is on the agenda of many nations nowadays, although its meaning can be perceived in different ways by different nations. In the EU, energy poverty refers to the situation in which households are unable to access essential energy services and products (European Commission). This affects 35 million people in the UE alone, in the world numbers are more complicated to calculate as large populations in the African and South Asian areas don’t even have access to safe energy (NGO: Habitat for Humanity). Nevertheless, there are some studies (such as this one published in the PMC in 2022) that relate energetic poverty to our health (physical and mental). The first conclusions pointed to poorly insulated houses when it comes to a higher probability of exposure to energetic poverty. This factor is linked to the area of residence (in which part of the city we live) and to the consumer’s habit of restraining energy consumption.
The worst-case scenario is the status quo
This profitable industry is responsible for 40% of annual global CO2 emissions: building operations account for 27% of the total annual emissions, while the production of building and infrastructure materials as well as construction is responsible for an additional 13% of the total annual emissions. Embodied carbon is an important thing to consider as it’s the ecological or carbon footprint of the product, in other words, the impact of the production/extraction, manufacturing, and transportation of the material, beyond its lifecycle or use time.
In 2040 approximately 2/3 of the global building stock will be buildings that exist today, meaning that the actions we take today will have a direct impact on tomorrow’s development of sustainable cities. There are several studies on this topic including a report by the United Nations Environment Programme (UNEP) which estimates that the production of building materials such as cement, steel, and glass accounts for approximately 11% of global greenhouse gas emissions. It is clear that there’s a problem with the materials used nowadays to build, and how an inefficient use of resources is contributing to climate change: water and noise pollution, air contamination, excessive mining, and high energy usage.
By analyzing materials widely used, we have realized how ineffective and wasteful they can be: both for the environment and our health. Some examples of this inefficiency are asbestos, PVC, or silica. Asbestos used to be a major choice due to its excellent heat-resistant and insulating properties: it was contemplated for thermal insulation, roofing, tiles, and any surface through which heat could escape. PVCs (polyvinyl chloride) are a known type of plastic that causes health hazards during its decomposition. In the case of silica (silicon dioxide), glass’ main ingredient, it was discovered it can cause airways-related illnesses after a long exposure. Silica particles are found in the air due to the dust that is raised during construction, which makes it a high pollutant. The list goes on and on with materials that you may have never heard or thought of before, but what about those that you can spot from your position right now? Chances are that you may be looking through the window now, and what are they made of? Bingo! Glass.
Glass is the status quo
Glass is scalable and economically feasible.
Glass is useful: in packaging, as a container, for insulation (not as much as you think), etc.
Glass is rooted in our building industry because its properties are difficult to substitute with just one material.
Glass is taking us off target. We produce 209 million tonnes of glass annually, which its subsequent product is 95 million tons of CO2 into the atmosphere, and its poor insulation properties increase the energy costs of buildings by over 35%. These numbers are expected to increase to nearly 5 times by 2035 because of increasing demand for materials to build with, and increasingly extreme temperatures.
The UN Sustainable Development Goal number 11 aims to develop sustainable communities and cities by 2030 (which also relates with SDG 12: “to improve resource efficiency, reduce waste and pollution”). Since the start of the 20th century, glass has been widely used as a construction material, and current statistics suggest that this trend will persist unless other environmentally-friendly alternatives gain more popularity.
Unless there is a comprehensive decarbonization effort in existing buildings globally, they will continue to release CO2 emissions in 2040, making it impossible to reach the Paris Agreement’s goal of limiting the global temperature rise to 1.5°C.
Current efforts to solve the carbon footprint of buildings don’t really solve the whole problem, with solutions like green concrete only slightly impacting the embodied carbon of the building(the amount of greenhouse gas emissions associated with the construction materials and processes used to build a structure), and not dealing with the long-term energy inefficiency and operational carbon footprint of the building, and glass alternatives like double and triple glazed glass may improve energy efficiency, but their production and transportation require high amounts of energy and generate significant greenhouse gas emissions, contributing to climate change. The complex manufacturing process and high cost of these windows make them inaccessible to the public and difficult to recycle, leading to potential waste management issues.
Wood as a solution
We need new materials for tackling the major problem that glass inefficiencies cause.
This is why in Ecoligna we have decided to take action by creating Spectralite. A renewable and sustainable material that can not only reduce the amount of emissions emitted in the glass manufacturing process, but rather prevent the amount of energy wasted due to poor climatization in homes.
Wood has been around in building since Ancient times. We tend to have a wrong perception of it as a construction material (maybe because we are prone to see it as breakable, rotting, and flammable). However, the wood composite (50% carbon, 42% oxygen, 6% hydrogen, and 2% nitrogen) has proved to be one of the strongest: its breaking strength is among the highest, considering its low density. Comparable to materials such as Kevlar or fiber-reinforced composites, its structure contains a high percentage of air inside (around 50%), which is a property that enables it to have many uses.
Wood is porous, meaning that the air inside makes it lightweight and the cellulose walls bring stability and ridgity.
The process: the chemistry behind transparent wood
Transparent wood uses the same method of lamination to gain extra stability and robustness. It doesn’t need it in terms of energy efficiency as it is 5 times more effective than glass in that matter. It comes from a raw material that insulates temperature, but its chemical structure varies to adapt to the new optical properties obtained with the final result.
Let’s go step by step to figure out how transparent wood was initially created. Out of the 50% of the wood that is not air:
- Cellulose fibers: 40–50%
- Hemicellulose: 20–30%
- Lignin: 20–30%
- Extractives and other substances: <5%
The researchers at the KTH Royal Institute of Technology in Sweden wanted to eliminate the component that gives wood its color, lignin. Delignification is the name of the process of removing this specific component receives, and it was chemically carried out in the labs in its early stages.
The process starts being similar to the paper production one. Wood is chemically treated in order to remove lignin, a composite that accounts for 20–30% of softwood (pine, spruce, and fir) and 25 to 35% by weight in hardwood (oak, maple, and birch). Firstly, bases such as sodium sulfite (Na2SO3) and sodium hydroxide (NaOH) are put with wood in a solution. After some hours, the treated wood was subjected to bleaching with sodium sulfide (Na2S). Then the level of aligning would be dramatically lowered to 3%. Once the drying has been completed, we will be left with the structure that will serve as a structure to build transparent wood. Cellulose (60%) is the main component once delignification has been properly carried out.
After delignification, we find a nanoporous polymer (a very long chain of molecules with holes in it). Through WPCs, polymers that absorb the same quantity of light (refractive index) are introduced in the molecule.
Wood vs glass
“Skyscrapers guzzle energy” that how this article in The Guardian summarizes how tall buildings require up to 40% more gas for heating than compared to low-rise buildings (relatively).
A study found that high-rise office buildings with 20 or more stories consume almost two and a half times more electricity per square meter of floor area compared to low-rise buildings with six stories or less. These skyscrapers are characterized by a major use of glass as a facade material, a fun fact that explains well the inefficiency of this material.
As mentioned before, windows play a huge role in the insulation of buildings. They are the main leakers of heat in winter months (and pouring heat during summer). One way or another, climatization encompasses good protection from the temperatures outside.
Conduction is the process through which heat in transferred via solid media, and it’s the type of heat transference applied to windows. Usually, transparent wood has a higher thermal diffusivity value than natural wood species, approximately 0.1 to 0.7 mm²/s for transparent wood.
Thermal conductivity is attributed to the exchange of energy between adjacent molecules and electrons in the conducting medium. (Encyclopedia Britannica, 2022)
In glass, this problem is minimized through the lamination process, and we can find it in double or triple-pane windows. The mechanism is simple: introduce resistance to temperature to cross with tiny air sacks between one glass sheet and another. The most efficient glass windows in this scenario are high-performance triple-glazed windows, although they have a high embodied carbon quantity (learn more about this method through this article by Glass for Europe).
If architects are sticking to glass is because it has many other remarkable properties such as hardness (resistance to scratch), chemically resistant (a point in its favor is its resistance to acids or moisture), and last but not least, its optical properties.
The problem with this process is that it requires a great number of chemicals and time (if we compare it to glass), which makes it slower to scale and deliver on time the material. In Ecoligna, we have developed another way of making transparent wood, which addresses the two problems presented by the first experiments.
Transparent wood conserves its natural cellulose, whose strength is comparable to steel. Cellulose’s high tensile strength is due to firm hydrogen bonds between the microfibrils, units of tightly packed cellulose molecules that make up the molecule. The tensile strength of cellulose microfibrils is comparable to that of steel. Moreover, in the processing of Spectralite we introduce a series of energy-absorbing polymers that can reinforce the robustness and strength. The combination of both of these polymer fillers and the natural fiber improves Spectralite’s durability and lighter weight than its competitor.
It can withstand stronger impacts without shattering, instead of bending or splintering. Transparent wood is compatible with existing industrial processing equipment, facilitating a smooth transition to manufacturing.
Considering these potential benefits for building design, manufacturing, and the environment, the advantages of transparent wood are evident, and Ecoligna develops the best process to scale this material up.
Ecoligna’s process: from cell isolation and culture to bioprinting it at large scale
It can be divided into 4 steps:
- Cell isolation and culture: Identify and separate the cell types in wood responsible for lignin biosynthesis.
- Lignin inhibition: Use gene editing to modify the wood cells to reduce lignin biosynthesis in those cells.
- Bioprinting: Use 3D bioprinting to print the modified wood cells into a desired shape and form.
- Post-processing: process the printed wood material to remove remaining lignin & impregnate the processed wood material with an alginate-chitosan polymer to enhance its mechanical and optical properties.
Conclusions: expanding Spectralite’s Use and Advantages
After research and development, we would partner with existing building owners to test the mechanical properties of our transparent wood windows and optimize our production process before entering the market with a fully scalable and durable material.
It’s time to switch to a more sustainable construction sector. Transparent wood could be 3 times cheaper than glass, 5 times more thermally insulating, and 9 times stronger. With Ecoligna’s product, Spectralite, it’s possible to transition into more durable, efficient, and greener materials.
Thank you for your interest in Ecoligna, visit our webpage and see our one pager for more information! Check out the references here, don’t hesistate to reach out on Linkedin for any further carification.
