12 Technologies Which Could Save The World

We're familiar with solar panels, and solar is probably the most promising renewable energy source. But we are on the verge of a major change in the technology.

"Power-generating windows are already available, and companies are working hard to cut costs and improve efficiency," says James Murray of the website BusinessGreen. "But the most exciting aspect of solar glass is its position as the most visible example of thin-film solar technologies – lightweight, flexible, and printable solar cells that can be integrated in everything from clothes to car park canopies. Forget solar panels – within a decade, solar cells could be everywhere."

Sometimes the simplest technologies are the most important. Solar lamps sound like a punchline to a joke, but they are providing free, carbon-neutral lighting for millions of families in Africa and Asia. And they have a more immediate benefit: Because most poor families rely on kerosene lamps, the uptake of solar has led to a huge improvement in air quality. "SolarAid has now sold more than 1.5 million solar lamps in Africa, saving families $215 million in kerosene costs and leading to 3.6 million people reporting better health as air pollution falls," says Murray. "It's a forerunner of the solar consumer electronics revolution – companies such as Apple are looking into integrating solar cells into phones and laptops."

Since some of these technologies feel like they're some way in the future, it's worth looking at one that is very much part of our lives right now: the humble light-emitting diode. Since the invention of the blue LED (and the white lights they allowed), the little lamps have become ubiquitous. "LED bulbs cut energy use by up to 80%," says Murray, "and, according to Philips, they will save 515 million tonnes of carbon emissions by 2020."

There is an endless back-and-forth over nuclear power between different parts of the environmental movement. Is it safe? Is it economic? But a new generation of reactors could possibly end that debate forever.

It's not the perpetually-30-years-away dream of fusion, but three fission technologies: thorium reactors, integral fast reactors, and travelling wave reactors. "Integral fast reactors promise to turn radioactive waste into power, travelling wave reactors promise to provide zero emission power for 100 years, and thorium reactors promise to quash nuclear safety concerns," says Murray. The three technologies have been mooted for decades, but may make it off the drawing board soon: General Electric and Bill Gates, among others, are backing them.

Biofuels have so far been, at best, disappointing. They work as fuels, but making them involves growing vast acres of crops which then can't be used for food. But it has been shown that all transport can run on them, including air travel, which is amazingly high-carbon. "How do you get enough energy crops to power the global aviation industry while leaving enough land free for agriculture?" asks Murray. "Richard Branson and other airline bosses think the answer lies in algae that can be produced at scale in industrial ponds."

Steps have already been taken by a possibly unexpected group. Murray says that "those notorious eco-warriors in the US Air Force have already successfully trialled biofuels containing algae, and wider test flights are imminent".

It's well established that you can generate electricity from the difference in salinity between river water and the seawater it's flowing into, and a prototype osmotic power plant is already running in Norway. But an MIT team think they can make it cost-effective for commercial energy production. Murray explains: "The team reckon they have found a way to slash the cost of the semi-permeable membranes that sit between the salty and non-salty water."

As with so many of these items, it's already been shown that the technology works – the question is how to make the economics work as well. "One answer is to use the captured carbon to flush out yet more oil, which doesn't really help with the whole saving-the-world thing," says Murray. "But an environmentally sustainable alternative could be to use the captured carbon dioxide to make something, and a number of research projects are seeking to do just that."

For instance, there is a Norwegian project which hopes to use carbon dioxide, photosynthesis, and latent heat from the power plant to make algae-based fish food. Others, such as Germany's Sunfire, are exploring how to use carbon dioxide from the atmosphere to make fuel.

Modern building technologies can radically – and I do mean radically – reduce your energy bills. The average British household now spends more than £1,200 on energy per year. But with "Passivhaus" building, that figure could be reduced to around £100. It's already happening in lots of places worldwide: "Around 30,000 properties have been built or renovated to Passivhaus standards, which combine ultra-efficient insulation and mechanical ventilation and heat recovery systems to pretty much negate the need for conventional heating," says Murray. It's not cheap but would save money over the lifetime of the building, as well as making a huge dent in our carbon footprint, he says. "We could live in zero-emission modern homes and free ourselves from sky-high energy bills. Thousands of people already are."

At the moment, "grids" – the networks of cables and substations that bring electricity from where it's produced to where it's needed – are usually fairly local, which means that power has to be produced within a (comparatively) short distance of where it's going to be used. But that may change: Soon, as high-voltage direct current cables become widely available, and grid management technology improves, it should be possible to transmit electricity efficiently over hundreds of miles.

"A European grid drawing from solar farms in the south, floating wind turbines in the north, tidal and wave arrays in the west, and Iceland's geothermal reserves has long been regarded as an environmentalist pipe dream," says Murray. "But there is growing evidence that such a grid is technically feasible, particularly as energy storage and grid-balancing smart-grid technologies mature."

Yes, it's a bit of a cliché. Every "new technologies" piece has to have a section on graphene, the new wonder material that can do everything up to and possibly including your tax return. But, says Murray, graphene has the potential to "revolutionise" green technology: "From ultra-lightweight vehicles to ultra-efficient solar cells or ultra-effective supercapacitors, many of the most exciting graphene research projects are focused on tackling climate change."

This is pretty self-explanatory. "Yes, Bill Gates is working on a project to turn poo into drinkable water," says Murray. "It works, and he has drunk the results to prove it."

The big-ticket item that everyone looks to to save the world is, of course, geo-engineering. Seeding the oceans with iron to promote algae growth and dimming the sun with enormous solar mirrors or aerosols have been put forward as ways to slow the increase in global temperatures without any of that difficult lifestyle-change stuff. But the US National Academy of Sciences (NAS) says it would be "irrational and irresponsible" to try any of this stuff yet.

It may, however, become necessary, if warming can't be slowed by other means. The NAS says we should be investing more in exploring whether some forms of geo-engineering may be viable because the threat from climate change is so pronounced. Murray: "Basically, if it comes to this, we're already in a world of trouble."