Tag Archives: energy

Wireless Energy Transmission for my Laptop

When will my laptop be totally wireless, even to recharge the battery? The future might be sooner than we thought, and Nanotechnology will be part of it.

There are many types of Wireless Energy Transmission although none of them have gone further than a prototype. For home use, powerbeaming could be the technology to free our portable devices from wires. Powerbeaming works based on a Laser system at one end that beams to a Solar Cell at the other end that transforms light into a DC current.

Current lasers have a 30-60% efficiency that combined with a 40-50% efficiency of solar cells, brings the overall efficiency at a maximum of 30%, still not too bad compared with electric bulbs. But Nanotechnology might boost these efficiencies at both ends.  

Solid-state lightning  promises up to 100% efficiency to convert electricity into light, once that we have atomically precise manufacturing technologies to arrange light-emitting building blocks in a controlled manner.

Today’s CIGS, CdTE or thin-film silicon are bringing down prices of Solar Cells. The ability to manufacture defect-free nanomaterials would improve efficiency at an exponential rate. With laptops foreseen to be equipped with solar cells in less than 10 years, solid-state lightning beams could be a wireless replacement to a wall socket.

 Picture from Wikipedia: NASA prototype of lightweight plane powered by a laser beam and a solar cell.

It Is Time for Renewable Energy

The high prices of oil in the seventies stimulated the research for alternative sources of energy. Nuclear power plants emerged as a very cost-effective energy source, though always controversial. Windmills and solar plants were in their infancy and too inefficient, while hydroelectric plants, apart from the high environmental impact, only can cope with a small percentage of the energy demand. In the eighties and nineties oil prices went down, and with cheap oil the progress on renewable energies slowed down.

Now, the high oil prices have returned driven by the increasing demand for energy in the developing world (specially China and India). The high price is making economically viable to extract oil from other sources, such as tar sands or liquefied coal. This means oil reserves will still last for a while, but oil will remain expensive.

Add the concerns on global warming, and this time renewable energies are here to stay. Many governments in developed countries are considering to tax emissions of CO2. This tax on coal, oil and gas power plants, with high oil prices, would start making renewable energies a cheaper alternative. It is what Google.org calls RE<C, or renewable energies cheaper than coal. Google’s initiative will focus on areas such as solar thermal, wind, and geothermal, that promise utility scale energy production.

Solar technologies are one of the most promising option to power the planet cleanly. New thin-film photovoltaics with mixtures of new materials (cadmium telluride or CIGS) are bringing costs down and built on top of steel and crsital, the cells can be part of the roof structure of buildings or vehicles. The efficiency of this new solar cells is lower than bulk silicon cells, but the efficiency is improving at a pace close to Moore’s law in computers, with big names, as IBM, getting involved. With the promise of nanotechnology bringing new techniques and materials, like carbon nanotubes, expect an efficiency boost in the coming years.

If Internet made the network decentralized, solar cells will also make power generation a distributed process in 20 years.

Related reading:
Another silicon valley? From The Economist print edition Jun 19th 2008