When thinking about the sustainable cities of the future, we envision a grid of roads, vertical farms, and skyscrapers, but what if a different urban perspective was on the horizon? Saudi Arabia is planning to disrupt the vertical, and grid-like trend with “The Line,” the backbone of the Neom megalopoli. At a cost of $500 billion, they’re touting this 100-mile-long linear city as the most sustainable urban complex in the world. And one with some cutting edge renewable technologies … like generating fresh water in a desert. But will it work? Let’s explore if Neom is a flight of fancy or the future of sustainable cities.
Blending Greek and Arabic languages, Neom means “new future”.1 And it might be a very near future too according to Mohammed bin Salman, the crown prince of Saudi Arabia. Back in 2017, the Saudi billionaire announced The Line would be completed by 2025, but recent estimates predict it’s most likely 2030.2 3 That’s still an aggressive timeline for a mega-city that will be 33 times larger than New York City.4 This project is part of the Saudi Vision 2030 program5, whose…bottom line…is to develop new avenues for the country’s economy. So many possible puns with this one. So it’s not a coincidence that the prince announced the Neom project in 2017 … just a year before the oil price hit a new low: 63% lower than the peak in 2012.6 Saudi Arabia has been heavily reliant on its oil reserve, the second largest of the world.7 But they realized this could pose a risk for the country’s future, so instead of oil, they bet on technologies, scientific research, and tourism.
So, what’s special about Neom? The project boasts the Saudi linear city as a revolution in urban living.8 Saudi Arabia will build this smart infrastructure in the northwestern Tabuk Province. Strategically originating at the junction between North Africa and the Arabian peninsula, The Line will be within a 4 hour flight for over 40% of the global population.9 Besides Saudi Arabia, The Line will cross Egypt and Jordan. In fact, the Neom project also includes construction of a bridge across the Strait of Tiran connecting Saudi Arabia with Egypt.
Expected to host 1 million people, the Neom urban design will feature three levels.10 The top ground layer will be a fully pedestrian area with green parks and zero cars. Just underneath, they’ll build a services area including shops and offices. At the very bottom, “The Spine” will connect the city modules along The Line with AI-driven vehicles, metro and ultra high-speed trains. You’re supposed to be able to buzz through the whole route within 20 minutes.
The project has some crazy flights of fancy, from creating the illusion of a giant artificial moon using drones to cloud seeding to produce rain, but setting those aside and focusing on the more meaningful approaches, one of the big goals of Neom’s designers will create a renewable oasis. They claim clean energy will produce freshwater from the sea and power the whole infrastructure.
That all sounds great – but there are some environmental and social impacts to consider. The Line will cross the Jabal Al-Lawz, the “almond mountain” in Arabic, one of the most popular tourist sites in Saudi Arabia (KSA).11 The Neom website acknowledges that this area is a challenge for accessibility and will likely be the least populated zone of the whole infrastructure. And The Line is already impacting people who live in the area. Saudi forces are trying to deport around 20,000 al-Huwaitat tribe members.12 After the suspicious death of a tribe activist in 2020, human rights organizations called for a UN investigation.13
On top of all that, is the Neom project even economically viable? Research conducted just after Neom’s official launch reveals some economic challenges.14 Despite the fancy website, the many advertising videos and the intention of turning Neom into a free-trade zone, some experts point out that the Saudi government will have a hard time attracting private investors.15 That’s because of the lack of information about the city development, excessive bureaucracy and unclear regulations.16 17 Despite the crown prince’s enthusiasm in his over the top presentation18, many scientists are skeptical about his dream coming true. Like Marc Lavergne, the director of the National Center for Scientific Research (CNRS), who believes a project like Neom isn’t viable from the economical and technological point of view in such a short time.19
So, does that mean Neom is just a public relations strategy or a real project? Well, we’ll need to see how things progress down the line, but some of the technologies Saudi Arabia is trying out could be a huge benefit for sustainability on a global scale. That’s why it’s worth taking a deep dive into some of them. First, let’s look at the pros of some of these technologies.
Groundbreaking tech in The (pipe)Line
One of the key assets of The Line is their advanced transport system. Its underground trains are supposed to operate at over 300 miles per hour, but are there any trains reaching that speed at the moment? There are two options: maglev and hyperloop trains. Last year, the Central Japan Railway Company introduced the L0 Series Improved Superconducting magnetic levitation (SCMAGLEV)20. You’ve got to love acronyms. With a max speed of 310 mph21, the SCMAGLEV levitates 4 inches above the rails. In fact, levitation overcomes the problem of friction between the wheels and rails, which maximizes velocity. But what makes it levitate and move forward?22 These trains float thanks to the repulsion force between two sets of magnetized coils. The first set, with the north pole facing up, runs along the maglev track (guideway) and the other one, with north pole facing down, is underneath the train’s carriage. Once the train is up in the air, an electric current is passed through the propulsion magnets which are set to alternate north and south poles. By constantly changing the direction of the current, the magnets continuously switch their polarity. The resulting magnetic fields push both the front and the back of the train forward. Also, the voltage powering the magnets can be used to power the train appliances. Unlike the original L0 series, the improved SCMAGLEV is fully powered by a more innovative and eco-friendly inductive system. This gets electricity wirelessly from the coils without relying on a gas turbine, which means no exhaust emissions. But there’s another major advantage. Using liquid nitrogen and liquid helium, Japanese engineers cool the onboard SCMAGLEV’s electromagnets down to 452 degrees Fahrenheit below zero23. At such low temperatures, the electrical resistance of their magnets’ raw materials, niobium and titanium, is basically zero. This makes these superconducting electromagnets generate electricity even after the power supply has been switched off and produce magnetic fields that are up to 10 times stronger than normal electromagnets.24
Magnetic levitation is also one of the principles of Hyperloop technology. I’ve done a deep dive on Hyperloop in another video, which I’ll link to in the description, but to break it down quickly here … it’s essentially a maglev train in a vacuum-sealed tube. The hyperloop’s low-pressure system gets rid of the air resistance, so moving in a near-zero friction environment, pods could travel much faster than maglev using lower energy. Elon Musk proposed his Hyperloop concept back in 2012.25 Since then, he’s encouraged innovators to try and make it a reality. As of today, Virgin Hyperloop One (VHO)26 seems to be in the fast lane…or track…, with their pods designed to glide at the near-supersonic speed of 670 mph.27 Hyperloop portals would allow people to move swiftly from one urban center to another. Richard Branson’s company signed a deal with the KSA’s transport ministry to assess how Hyperloop could fit the country’s innovative infrastructure plans.28
Other than fast transportation, the Neom project will need a lot of fresh water to quench the thirst of its million residents, which is no small feat considering that Saudi Arabia will be one of the nine most water stressed countries in the world by 204029. So far, the country has relied on desalination plants, which remove salt from seawater using two established processes. The first, and oldest method, is thermal desalination. Basically, you heat up seawater and cool down the produced steam back into fresh water. The newer and more prevalent alternative is reverse osmosis (RO). In this case, you apply high pressure to force seawater through a semi-permeable membrane which separates salts from water. Although less energy intensive than the thermal approach, RO still requires a high energy load, which currently means a lot of fossil fuels being burned. On a global scale, desalination plants are responsible for ca. 76 million tons of CO2 equivalents per year. And if we don’t decarbonize the desalination industry, the already…salty…carbon budget is supposed to rise to 500 million tons of CO2 equivalents per year by 2040.30 Another major environmental impact of RO is the discharge of the residual highly concentrated slurry (a.k.a. brine) back into the ocean. Being much denser than seawater, hypersaline brine sinks to the bottom. The increase in salt content triggers a drop in oxygen which harms the marine ecosystem.31 The bad news is that the global number of RO desalination plants has increased exponentially over the last 60 years. And guess who’s in the lead? Yep, Saudi Arabia, with 15% of the global capacity.32
But the Neom developers are about to deliver a sweet deal for the KSA and possibly the entire world. They’re partnering with the UK-based Solar Water Plc to develop the first-ever solar dome to produce clean water out of the Red Sea. The exposed part of the dome is a glass semi sphere extending 25 meters upward. This covers an equal sized metal underground semi sphere which is filled by seawater coming in through a glass aqueduct. The dome’s advanced thermal desalination method taps into Concentrating Solar Power (CSP) technology. Basically, a large number of parabolic mirrors will focus solar radiation onto the glass dome. The localized greenhouse effect will heat up the lower metallic…kettle… containing seawater. The resulting steam will be pumped out through pipelines. After condensation the fresh water will feed reservoirs and irrigation channels. Unlike in the conventional RO process, Solar Water Plc said the waste brine collected at the bottom of the dome will be reused for different applications, like lithium batteries, grit for roads, fertilisers or detergents. According to their CEO, this 100% carbon-neutral desalination plant is the future solution for accessing environmentally safe and sustainable fresh water.33 The leader of Neom’s water sector said the dome will generate 500,000 cubic meters of clean water per day and produce energy out of wastewater to close the loop.34 But what about the cost? A recent study says solar and energy storage technologies could drag down the global average levelized cost of desalinated water to around $1.20/m3 by 2050.35 Well, the solar dome designers aim to water down the cost of fresh water generation to $0.34/m336, which is…unsalted…peanuts compared to fossil-fuelled desalination plants. The first solar dome is currently being built and scheduled to be completed by the end of this year. It’s going to serve as a test for industrial applications worldwide37 … and something to keep an eye on.
But what’s going to power all Neom’s other fancy technologies? Through a $5B partnership, Air Products and Saudi-based ACWA Power will build the world’s largest green hydrogen and green ammonia facility. An innovative 4 GW hybrid system combining solar and wind power plus energy storage to power the city and export surplus clean energy worldwide. Using Thyssenkrupp electrolysers38, the plant will produce 650 tons of hydrogen per day. Thyssenkrupp engineers will build a 20 MW modular alkaline electrochemical cell … man, that was a mouthful … to break down water into hydrogen and oxygen.39 The use of alkaline aqueous solutions (KOH or NaOH) as electrolytes will boost the electricity transmission, which means the hydrogen production will be more efficient.40 Up to 82% for the Thyssenkrupp unit.41 Also, powering electrolysis with renewables rather than fossil fuels will reduce the process’ carbon emissions by ca. 55%42. The 650 t/day of hydrogen produced will feed the Haldor Topsoe rig,43 where it will be reacted with nitrogen and converted into 3,500 tons of green ammonia per day. It’s a lot of steps, but after cooling it down, the liquid green energy-rich ammonia will be safer and easier to carry around.44 It’s the easiest and safest way to transport hydrogen. At its final destination, the eco-friendly ammonia can be cracked back into hydrogen and nitrogen. The plan is to use hydrogen to fuel buses and trucks. And with high insulation levels and average wind speeds of around 10 m/s, the NEOM location is well suited for a combined use of solar and wind power. Air Products’ CEO said the green energy plant will save over 3 million tons of CO2 per year.45 This is all expected to be operational in 2025 … at least, that’s what Neom’s advocates are saying.
The fine line between dream and reality
Which brings me to the potential downsides of all of this. The Neom’s technologies sound very promising. But are they going to be ready and functional by 2030?
As for the near-supersonic trains, the short answer is … very unlikely. One of the Japanese maglev trains hit a world record speed of 374 mph46 back in 2016. Yet, it was only a test run. The $84B first commercial-scale track between Tokyo and Osaka won’t be completed until 2027.47 And that timeline might be extended. Local authorities are worried about potential environmental impacts and are delaying the tunnel digging along the route.48 And then there’s Hyperloop. Despite being much faster than maglev in theory, in practice hyperloop is lagging behind. Virgin Hyperloop proved its prototype-scale pods at their Nevada track, but it was only this past November that the first passengers rode the test track. It was the world’s first experiment ever for this technology and was also a short and relatively slow ride. Only 550 yards at around 100 mph.49 Branson’s team is hoping to reach commercial scale by 2030, but it’s still not clear if they’ll meet that deadline.50
What about the solar dome? Does it hold…freshwater? The application of CSP technology for thermal desalination has never been demonstrated on a commercial scale yet.51 To add to that, Solar Water Plc is quoting a very competitive price. This obviously raises doubts on the long-term reliability and economic feasibility of Neom’s solar dome. Leon Awerbuch