'Cleaner' or more Sustainable technologies in Fuels and Fuel Cells.
By now most people in the western world know that the burning of fossil fuels increases the carbon dioxide levels in the atmosphere causing the greenhouse effect, warming the planet with consequent environmental changes.
Idealy solar panels that photosynthesise, coverting sunlight directly to electrical energy will alleviate the greenhouse effect by removing the need to use fossilised hydrocarbons for fuel. A square of 168 could provide enought 'solar power' for the present population 6 billion, to enjoy a comfortable life.
Electricity is not the prefered energy for mechanical power as it needs converting, so sadly internal combustion is popular. Steam engines do produced physical power directly but have not been developed sufficiently.
Whether or not enough bio-fuel can be sourced to produce the enormous amount of power presently used, is questionable, but unless nucelar fussion or even more unlikely anti-matter can be developed there is an increasing need to find alternatives to the internal combustion of fossil fuels.
However 'Toyota' have produced a car that gives out so little pollution that operating in Los Angeles it would actual clean up the air.
Steam Engines (Tiny Power USA) | Hydrogen Fueled Taxi | Fuel Cells
For the future :- Anti-matter | Light Capture | Nuclear Fusion