Story link: http://www.goodnewsindia.com/index.php/Supplement/article/alternate-energy-breakthroughs
Despite their allure, alternate energy systems have really not been able to displace conventional, non-sustainable, polluting or hazardous sources like coal, petroleum or nuclear. Reasons are cost and scalability. Take solar energy. It is estimated that several times the planet’s total energy need arrives from the sun but costs of gathering and effectively storing it are prohibitive.
Nanosolar Inc, in California, USA began with a checklist of seven stumbling blocks in the way of solar energy’s success and has in 5 years of work, been ticking them off as overcome. It is now ready for wide commercial sales.
What was the state of solar technology that Nanosolar has improved on? The first generation technology used bulky, brittle and expensive silicon wafers to convert solar radiation to electricity. Costs were so prohibitive that it never amounted to much more than proof of concept. The next generation thin-film cells used much lesser quantity of semi-conductor material but the fabrication method of vacuum deposition resulted in low yields and high costs. Fragility continued to be an issue. Neither approach was amenable to large scale production.
Nanosolar’s approach is to literally print solar cells on continuous rolls of flexible, inexpensive substrate. It begins with Copper Indium Gallium Diselenide [CIGS] , a semi conductor material proven in the thin-film cell. Particles of CIGS are dispersed in the ‘ink’ and because of the nano-scale they maintain the element-level ratio required for photo-voltaic action. At nano scale, photovoltaic semiconductor quantum physics occurs. The cells are able to abstract energy from a broader spectrum of solar radiation than in the earlier cells.
With this approach Nanosolar has achieved lower cost of semiconductor and substrate materials, nearly nil rejection rate of produce, continuous production with least human error and economies of scale. It’s a breakthrough in fabrication technology. Nanosolar is building a large production facility and mass sales will begin this year. It plans to make roofing panels with pre-installed solar cells. They will also sell flexible solar cell sheets. Because these cells are bendable one can conceivably unroll a carpet of cells on a desert and draw power from it.
You can evaluate the maturity of their business from the fact that Google’s legendary founders spotted it in 2002 and became angel investors. A senior executive from IBM joined them and Nanosolar has effortlessly raised $100 million to build a factory. It is targeting sales of $100 billion by 2020. Not inconceivable at all. Nanosolar
The second huge stumbling block for alternate energy enthusiasts is the storage problem. Whether electricity is generated by wind or solar it is always uneven because of unsteady wind and sunshine regimes. Despite a number of available options, the storage work-horse is the rechargeable battery. Its size and cost make them unattractive. When cars are sought to be run on batteries the problem of quickly recharging them becomes yet another issue.
It is the point of view of electric cars -given the huge market potential- that drove EEStor in Texas, USA to its breakthrough innovation. Cleanly bypassing all manner of electrochemical storage devices - ie batteries- EEStor broke new ground with capacitors. In simple terms, the ubiquitous capacitor is two metal plates separated by a material known as a dielectric. A capacitor can repeatedly receive and discharge large bursts of electrical energy. EEStor has grown this basic principle into a marketable battery. The company is highly secretive and responds to no queries, comments or reviews. It does not even have website! So we don’t quite know how the huge electrical charge, ususal to capacitors, is tamed and issued in a steady stream required by cars.
Richard Weir, its confounder speaks little as in a recent interview to MIT’s Technology Review magazine. They will have automotive batteries ready for cars this year, he says. According to the magazine, “The company boldly claims that its system, a kind of battery-ultracapacitor hybrid based on barium-titanate powders, will dramatically outperform the best lithium-ion batteries on the market in terms of energy density, price, charge time, and safety. Pound for pound, it will also pack 10 times the punch of lead-acid batteries at half the cost and without the need for toxic materials or chemicals...”
EEStor’s products, to be known as Electrical Energy Storage Units [EESU], will start coming off a production line this year. The first EESU will be a 45 kg unit that gives a car a 350 km range and can be recharged in under ten minutes. In comparison with petrofuels, a EESU cars’s running cost will be 80% cheaper.
EEStor’s EESU can facilitate large scale, low cost solar energy storage. While Nanosolar’s work is incremental, EESUs make a quantum leap in innovation. EEStor claims its product is ‘game changing’. The whole sustainable energy scene could be changing too. MIT article