10. Air Purifying Roof Tiles

A big problem with green technology is making it as practical as it is useful. With this

in mind, a new trend in practical green technology is the coating of roof tiles with titanium

dioxide, which is useful in cleaning the air. Titanium dioxide works as a photocatalyst

by oxidizing nitrogen oxides and volatile organic compounds into soluble nitrates and

fatty acids when exposed to UV light. Studies have shown that a thick coating of material

on roof tiles reduces 97% of target greenhouse gases, while a thinner, cost effective coat

still reduces the target gases by 88%. This means that it could cost just five dollars

to coat an entire roof with the purifying compound. One home could remove 21g of nitrogen

oxide a day, which is the equivalent of what a car releases driving 18,000 km. Widespread

application would allow every home in the world to become a mini-air purifier. The idea

is still in the testing phase, but early results have been extremely promising. The lighter

color of the tiles also has the added benefit of producing a small cooling effect. There’s

also a possibility of producing tiles to remove carbon dioxide, but this would decrease the

practicality of the tiles by making the roofs harder to install.

9. Eco-Concrete

Eco-concrete is a green technology that combines strength, practicality and air-purification.

It’s designed to eat smog and pollution by converting nitrogen oxide into harmless

nitrogenous compounds. It has been shown to reduce these gasses by up to 45% in the right

weather. The concrete has already been installed and tested in Holland with promising results.

The biggest problem with Eco-concrete comes from its cost — compared to normal concrete,

it costs quite a bit more because of its use of titanium dioxide. Researchers are currently

working to find a solution to the problem and increase the concrete’s financial feasibility.

8. Fixing the Plastic Problem

At age 19 most people are worrying about work or college, but Boyan Slat had his eyes on

something bigger when he came up with a method to drastically reduce the amount of plastic

in our oceans. Though plastic has been a blessing to us in terms of convenience, it has also

become a curse in the way it affects the environment and kills millions of marine animals every

year. Slat recognized the severity of the problem and established an organization known

as The Ocean Cleanup in response. He went on to develop a method that has been proven

to be logistically, technically and financially feasible. It works using natural currents

in the ocean and wind to help move the garbage towards collecting platforms, where it would

be mechanically removed and recycled.

The price tag of this massive cleanup project is $43 million a year, but that’s 33% cheaper

than other methods that promise to remove the same amount of plastic. The Ocean Cleanup

is currently in the stages of raising money to implement their plan. It has been tested

with computer models that show it should be able to clean up half of the garbage in the

Great Pacific Garbage Patch. Furthermore, its proof of concept test was successfully

done in the Azores. While this massive undertaking is a great step in the right direction, Slat

believes more needs to be done to fix the problem completely.

7. Cool Pavement

Dark pavement used for most roads absorbs the sun’s energy and heats up the surrounding

area. In the summer, pavement can reach up to 120-150°F, but Cool Pavement has been

shown to reduce this by over 40°F. With pavement occupying 35-50% of the space in a city, this

could have a huge effect on the overall temperature of the city itself. Researchers at Berkeley

are currently trying to figure out what the best color would be for cool pavement to maximize

its cooling effects. The two best options are to create reflective coating for existing

pavements or create a new type of pavement made from lighter, more reflective material.

Other benefits include a decrease in pollution and smog, slowing global warming, saving energy

by decreasing the need for air conditioning, and even decreasing the need for street lamps

at night because of the reflective surface. While there is no way to know exactly how

much coating an entire city would benefit the environment, Cool Pavement has been helping

cities like Chicago that have paved their alleys with it.

6. Smog-Eating Buildings

Mexico City’s Manuel Gea Gonzalez Hospital constructed a 2,500 square meter facade that

breaks down air pollutants when exposed to UV light. The honeycomb increases the surface

area by 200% and allows the structure to neutralize the same amount of pollutants in one day that’s

produced by 8,750 cars.

In addition, the city of Milan is using a smog-filtering concrete facade to purify the

air. The architecture firm Nemesi and Partners have revealed their plans to produce an air-purifying

structure in front of the Palazzo Italia. The 9,000 square meter structure will take

about 2,000 tons of air-purifying concrete to complete. The concrete is made of 80% recycled

materials and works by breaking down harmful pollutants into unreactive salt molecules

when exposed to UV light. Nemesi and Partners are looking forward to presenting their designs

at the 2015 Milan Expo, and plans are already in the works to make these designs a reality.

5. Real Flower Power

Much of today’s green technology is made to mimic what plants already do naturally

to produce energy. Plants are able to create energy by breaking down carbon dioxide and

water into sugar and starch with oxygen as a byproduct. Scientists have been able harness

this energy by actually interrupting the photosynthetic process. This is done when the enzymes of

the plant split the water molecules. At this point, oxygen, hydrogen, and electrons are

produced and nanotubes are used to siphon the free electrons before they enter the electron

transport chain to run the rest of the process.

The process takes place in the thylakoids, which are located within the chloroplasts

of the plant cell. The thylakoids were modified to allow the nanotubes to detour the electrons

down a wire and generate an electrical current. Usually, plants aren’t very efficient at

producing energy from the sun and man-made cells generate up to 10 times the efficiency

of a normal plant. But this new technology has proven especially surprising because the

plant was able to generate twice the current of a similarly sized solar cell. While this

technology is still in its infancy, researchers are hopeful that it will soon have practical

uses and could be used to power household items or even entire power grids. Plus, increasing

the use of plants could help purify the air in addition to providing power.

4. Energy Harvesting Concrete

Laurence Kemball-Cook put a new spin on energy harvesting when he founded Pavegen in 2009.

Pavegen is a new type of energy-harvesting tile that converts the energy of a simple

footstep into electricity that can be stored or used directly by devices. While the kinetic

energy harvested from footsteps isn’t enough to supply energy to entire power grids, it

could be very helpful in powering things like street lamps or vending machines. Pavegen

is a working product in the process of becoming commercialized. In an attempt to showcase

its usefulness, Pavegen was actually installed at the finish line of the Paris Marathon and

was able to generate 4.7 kilowatt-hours of energy. Another benefit of installing Pavegen

is that it allows the footsteps and movement of crowds to be tracked to optimize space

and floor management.

While the tiles themselves are extremely practical, their installation could pose problems. The

tiles have to be made and installed in ground that’s durable, weather resistant, and highly

fatigue resistant. Furthermore, the tiles could be vandalized or stolen. There are still

many kinks that need to be worked out to make Pavegen a fully commercialized product, but

it’s definitely a step in the right direction.

3. Hyperloop

Elon Musk, the man behind electric car company Tesla, has a new idea up his sleeve. Known

as the Hyperloop, this system would be able to transport passengers from Los Angeles to

San Francisco in just 35 minutes, traveling at speeds of about 700 mph. The Hyperloop

would use an electric compressor fan at the front of each individual passenger pod to

surround it with a cushion of air and decrease friction, much like an air hockey table. The

capsules would then be accelerated in a low-pressure tube with magnetization.

Furthermore, the Hyperloop would be completely self-sustaining by placing solar panels on

the top of the tube and storing energy via compressed air. It wouldn’t disrupt the

farmland along the route any more than a telephone pole. Musk estimates the project would cost

about six billion dollars, which seems like a massive price tag until you realize that

California voters already approved nine billion to be allotted for a speed train between San

Diego and San Francisco. Musk feels that his Hyperloop will be more cost-effective and

sustainable than any other proposed high-speed trains. It would greatly decrease pollution

from cars and commercial airliners, as well as increase the efficiency and speed of travel.1

2. Phoenix Towers

Currently, the world’s largest tower is the 830 meter tall Burj Khalifa. It may be

in danger of losing its title to two proposed towers for the city of Wuhan, China. These

towers would stand at 1000 meters and would serve to clean local air and water pollution.

The towers would suck the water in from the surrounding lake, send it through a series

of filters and then back out into the lake. In addition, the towers will be lined with

a pollution absorbing coating and vertical gardens to pull even more pollution from the

air. The chimney in the middle of the towers will serve to naturally pull air across the

lake and oxygenate it. The towers will be completely self-sustaining thanks to wind

turbines, solar panels, and hydrogen fuel cells that would run on the building’s waste.

These elements will not only produce all the energy the towers need, but also generate

a little extra energy for the surrounding area. The towers are currently awaiting the

mayor’s approval, but it’s predicted that construction of this massive undertaking will

be finished by 2017 or 2018.

1. Tianjin

Most green technologies are simply products to help existing cities become environmentally

friendly. China is going a step further by simply constructing an entire eco-friendly

city from scratch. Known as Tianjin, this sustainable community for 350,000 residents

is expected to be complete by 2020 and will span over 30 square kilometers. The entire

complex will be powered by solar and wind technologies as well as feature rainwater

recycling, wastewater treatment, and desalination of seawater. Carbon emissions will be basically

non-existent with 90% of traffic being public transportation.

The city will be divided into seven districts, each with its own sustainability theme. The

Lifescape district will be in the heart of Tianjin and feature soil-topped mounds to

contrast the surrounding high-rise buildings. Eco-Valley will serve as a corridor for the

new light rail system to operate and connect the districts. Solarscape will act as the

administrative and civic center. Urbanscape will function as core of the city and utilize

vertical layering to reduce emissions and make efficient use of vertical space. Its

buildings will be organized as a honeycomb and interconnect using sky bridges. Windscape

will serve as a place for recreation and relaxation. Earthscape will function as the residential

suburbs and be filled with lush greenery. Lastly, Eco-corridors will bisect the city

and provide a path for animals to move about the city without human interference. If successful,

Tianjin could serve as a stepping stone for more green cities.