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Uncovering the truth of smart cities and water

By Catherine Knowles, Tue 5 Jan 2021

Water is becoming an increasingly important component of any smart city build or development.

IDTechEx has researched many areas of importance and interest around smart cities and water.

For instance, in the report ‘Smart Cities Market 2021-2041: Energy, Food, Water, Materials, Transportation Forecasts’, IDTechEx explains cities increasingly, and massively, depend on water technology as sea levels rise and for other reasons.

As such, cities will move to eliminating sewage systems by treating it where it is produced, bring in new agriculture systems, reevaluate global supply chains, consider how water can be used as an energy source, and more.

An important focus

According to IDTechEx, currently cities are killing the sea that is increasingly near to them and dead ocean areas are spreading.

They do this with untreated sewage, salt from desalination plants, chemicals from factories, leisure activities, marine vessels, and farm runoff of toxins and fertiliser.

The analysts state that instead they must farm the sea to maintain biodiversity, and create benign marine tourism and leisure activities.

Methods of distributing salt from desalination without killing anything do now exist, but deployment is slow.

Cities on the sea, and a move towards water power

Some smart cities are planned at sea and on reclaimed land, such as Forest City Malaysia, which promises a veritable jungle with ‘sounds of nature’ and self-watering greenery.

You can also currently buy a DND house on and under the sea in Dubai.

According to the analysts, cities will make all their own food, fresh water, and electricity to enhance empowerment, security, and affordability.

Electricity-making is even pivoting to water, with tidal turbines installed from Scotland to the Hudson River in New York, and wave power both being almost continuous and using almost none of the steel and concrete that produces 16% of global warming, the analysts state.

Notably, it takes a few hours to drop tidal turbines in, not 10 years as for hydro dams.

Part of the reason for water power is that there is less and less land for wind turbines and solar farms.

Indeed, silicon solar works better cold, so it is migrating to sea or lake as floatavoltaics.

New photovoltaic materials are even useful underwater, and photovoltaic paint is on the way, IDTechEx states.

Leaders in tidal power such as Simec Atlantis and Verdant Power have more and more companies chasing them, which is the same for wave power leaders such as Seabased, Wello and Eco Wave.

Even ORPC RivGen horizontal axis water turbines are proving viable in shallow rivers, and they do not disturb fish.

Finally, most water power is virtually continuous, with no massive batteries.

Leisure and freight on water

Over time, cities will focus more of their leisure industry and freight transport on the water.

IDTechEx sees several ways that even large ships can become zero-emission, despite the fact that today they each pollute as much as millions of cars.

At the other extreme, Swiss Seabubble aquaplaning water taxis are zero-emission, charged by small river turbines under the landing platform. These are also planned for Paris.

Smart agriculture and gardening

Today’s farming systems on land gulp water and boost global warming, IDTechEx states. They are being replaced by vertical farming, solar greenhouses, hydroponics in buildings, aquaponics and saline agriculture in marshes as sea levels rise.

Genetic agriculture will save water. Meat and milk will be grown in city laboratories, and managing with 1% of the fresh water will become commonplace.

Soliculture greenhouses on rooftops and elsewhere are adopting smart glass that provides electricity for the robots as well as optimally growing the plants, again with almost no water.

Robotic food cultivation is integrated with human facilities in parts of China, saving space and water.

Fish farming and barley, samphire, seaweed, and other vegetables growing in saline water harks back to the ancient Sumerians, but it is necessarily broadening in scope as global warming and people moving to cities makes land even more scarce, the analysts state.

In fact, there is a roadmap of many options to go even further. For example, aquaponics uses even less land than hydroponics, and costs less. This is the process of growing fish and vegetables in one closed system, the fish excrement feeding the plants.

When it comes to smart gardening, some are planning turf that produces electricity as well as tapping and filtering rainwater for use.

For instance, Xeriscaping is appearing in smart cities. This is the process of landscaping or gardening that reduces or eliminates the need for supplemental water from irrigation.

It is promoted in regions that do not have accessible, plentiful, or reliable supplies of freshwater and is gaining acceptance in other regions as access to irrigation water is becoming limited.

Xeriscaping is an alternative to various types of traditional gardening in necessarily frugal smart cities.

On the other hand, the trend to multi-purposing even extends to damp turf, vegetation, and soil. Plant-e is a company that develops products that can generate electricity from living plants, and Harvard University has biofuel cells using such fuels.

Smart water transport

Transport systems are being reinvented for smart cities, and necessarily so.

Hyperloop shooting passengers from city to city by magnetic levitation in a vacuum and Boring Company Loop shooting autonomous cars at high speed across cities will increasingly be tubes in seas, lakes or rivers for at least part of the way. This can even save cities money.

Autonomous underwater vehicles are zero-emission and they monitor offshore wind turbines, sea-floor mining, fish stocks, and more.

According to IDTechEX, we may even begin to see leisure submarines as taxis.

Thirsty desert cities

The largest challenge of the $0.5 trillion NEOM smart city in the Saudi Arabian desert is drinking water - all desalinated from the sea.

The Bill Gates Belmont desert city in Arizona is nowhere near the sea, and the state gets its water from the Colorado River, which is drying up.

By far its biggest challenge is water. It has to guarantee 100 years’ supply to be allowed to start.

Arizona-based startup Zero Mass Water’s SOURCE photovoltaic panels make electricity but also use the sun’s rays to pull water from the air.

Each panel has the potential to draw up to 10 liters (2.64 gallons) of water per day.

According to IDTechEx, this will help, but all the sources still leave that city with severe water conservation requirements.

However, Bill Gates has proven from his investments that the elimination of sewage distribution and treatment farms is coming when it is treated at the source, which saves huge amounts of water.

One new toilet has an electrochemical reactor that can break down water and human waste into fertilizer for fields and hydrogen, which can be stored in hydrogen fuel cells as a green energy source.

Even the little water used is treated enough to reuse for flushing or for irrigation.

IDTechEx has released a number of reports related to the topic of water and smart cities, all of which can be found on the IDTechEx website.

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