In the town of Arbedo-Castione located next to the enormous Alps, we will soon see the most bizarre architecture in Switzerland: a 120 meter high crane with 6 muscular arms, cleverly lifting and neatly arranged. each block of earth compressed into a tower towering out of sight; witnessing the hundred meter crane in operation, you will immediately associate the game City Bloxx on the old Nokia device. When the crane reverses the process of building the tower, the Earth’s gravity will pull each block of compressed land down to generate energy.
The enterprise behind this project is the Energy Vault, and the tall crane comes with the desire to solve the most difficult problem in the renewable energy industry: it can store the amount of energy generated that varies by the hour, uncertainty like the weather of wind and solar power generation systems. The two above-mentioned energy generation models are clean, both are good candidates in the search for alternatives to fossil fuels, but they are too unstable to become the foundation for the future of humanity.
Tower crane stores renewable energy.
If there is no way to generate energy when it is cloudy and windy, the world grid in general and key industries in particular cannot operate on renewable energy.
“You want 100% of the power supplied to the grid to produce no carbon emissions, but not so many ways to generate energy“He is a professor of chemistry at Duke University and the chief executive of Breakthrough Energy Ventures – a venture capital fund dedicated to startups seeking to store clean energy.
Toone also said that in order to remove carbon emissions from the energy industry through the sun and wind, the ability to store energy must develop further.
Endless resources but do not know where to store
Researchers and abundant capital investors are trying to find ways to store renewable energy effectively.
The technology that works best today is the lithium-ion battery, which is helping the entire electronics industry at the present time and is responsible for revolutionizing transportation. The process of making li-ion batteries is getting cheaper day by day, but the life expectancy is not so high, and the production line requires rare earth – a resource that was so few and owned Extremely toxic production process. Many companies are seeking to use cheaper, cleaner and more readily available chemicals, such as compressed air or hydrogen, but no one has yet found a way to replace the most efficient li-ion battery.
Energy Vault is another startup approaching energy storage, they are also looking for cheap and available resources. It turned out to be the gravity of our own planet.
To make this incredible technology a reality, the Swiss company received $ 110 million in capital from the Softbank Vision Fund; Their construction is a 6-towering tower crane, responsible for loading and unloading 35 tons of materials that are molded into blocks to create energy.
When renewable energy systems (such as wind and solar farms) generate surplus energy, the Energy Vault’s algorithm will order the crane to use that energy to stack the land mass into a tower. high – blocks of soil obtained during excavation of the foundation erected the other crane.
When the demand for electricity is rising – the peak hours of household electricity use, the crane will unload the blocks from the tower. The force created by the mass of the earth being pulled down by the Earth’s gravity will spin the generator and generate electricity.
According to calculations by Energy Vault, a standard project with 20 tower cranes will generate enough electricity to power 40,000 households in 24 hours. Over time, the cost of producing electricity this way will be lower than the use of fossil fuels.
In addition to the work at Arbedo-Castione, many Earth-based power generation projects are being developed in Scotland, Germany, the United States and Morocco.
Startup Gravitricity is based in Edinburgh, Scotland, not considering building towers but taking advantage of abandoned mines. The axle systems will pull 12,000 tons of heavy objects and let it drop freely into the deep mines. Gravitricity believes that it can generate electricity at half the cost of producing li-ion batteries without wasting energy.
Unlike Energy Vault’s cranes that can generate non-stop electricity for 8-16 hours, Gravitricity’s weight placed in the ground will only be able to generate energy from 15 minutes to 8 hours.
This is an attempt to improve how gravity is used
The idea behind these projects is that the descendant of a hydrogen pump has been around for decades: we use excess electricity to pump water back up, and then when it’s needed, we need to pour it down again to run the turbine. “But we can’t build new dams because the public is opposed to taking dams and changing the landscape“The CEO of Gravity Energy AG, Horatio von John said. Mr. von John knew he would face a backlash from the community, so he invested in an underground tank, using excess energy to Operating hydraulic pistons.
Hydrogen pump model to store excess renewable energy.
“With hydrogen pumping technology, we will need many square kilometers in some hilly land, with high and low lakes and then put another hydroelectric plant“He said. His underground tank is much more space-saving, about the size of a football field and is capable of generating 1,000 megawatts of electricity in about 4 to 10 hours.
Comparing two systems of Gravitricity and Gravity Energy AG, we find that they are less efficient than Energy Vault’s cranes. According to the developers of the electric tower crane, only with basic maintenance, the system can operate for more than 40 years, obviously more efficient than traditional batteries. With an investment of 8-9 million USD, they can store energy for about 1,100 VND / kilowatt-hour of electricity, along with “No energy consumption“and”Low operating costs“.
With more than US $ 100 million received from SoftBank, Energy Vault will increase the size of the project by several times. Robert Piconi, CEO of Energy Vault, plans to build a 150 meter high tower crane alongside the 120 meter cranes as originally planned.
According to experts, the system of storage and discharge based on gravity will be an effective method of grid balance. The amount of electricity produced by unusual solar / wind power systems, which can generate a lot but deviates from the household’s electricity usage time frame; Solar power generates a lot in the morning, but how many households stay home to use electricity? And solar / wind power is too unstable to sustain business operations, resulting in a surplus of renewable energy.
A system that utilizes gravity to store electricity surpasses li-ion batteries at two points:
– The system will not degrade as fast as the battery: obviously the charge-discharge cycle of a crane cable will be more flexible than the chemical reaction that occurs inside a battery.
– Can easily adjust the amount of energy output of electric tower crane through adjusting the weight of material block. Small masses that are released slowly will produce a moderate amount of energy over a long period of time, while large masses that are released will generate large amounts of energy.
But this is not a perfect system; Technology behind you to calculate weight and placement of each block correctly. According to Mr. Piconi, Energy Vault’s algorithm has been able to compensate for weather factors or crane quality over time.
Just relying on this new system is not enough
While applying gravity to store renewable energy, science is still improving the old li-ion battery technology, while looking for new directions. For a long time, we have kept seeing news of new battery technology to replace potentially explosive lithium-ion batteries; This is a good sign that science has not succeeded in the right direction.
These include other ways of generating and storing energy such as turning excess renewable energy into heat. Startup Malta is investigating the use of heat to melt salt at temperatures above 90 degrees Celsius, and then use electricity to cool another compound. When energy is needed, the system reverses the process to get cold and hot air, combining them to create steam to drive turbines.
Device model of Malta starup.
Recently, science has sought to make use of hydrogen – the most abundant element in this Universe – as a source of clean materials. At the moment, this process is still costly but at least, the researchers have still achieved certain breakthroughs.
The pain of making clean electricity but not being saved anywhere is still painful. But fortunately, the energy storage industry is on the right track. At the present time, let’s wait for the emergence of tower cranes to store energy, provide electricity to households with the force that holds the reality together.