Story link:



  Novel energy options

As petroleum inches unstoppably towards $100 a barrel and global warming is a widely shared experience, it is nice to know there are solutions for a future without either of these. Here is a round-up of some options for Indian researchers and experimenters to get started on. These developments are from overseas and are worth our attention.

The appeal of biodiesel is well known but there are concerns that when land use is changed to produce liquid fuel, food production may suffer and famines ensue. Tree based oils -as against those derived from field crops- do a little better on this score but they still need a lot of land and take years to establish.

That is why research began in the USA on algae that can yield biodiesel. Between 1978 and 1996, National Renewable Energy Laboratory [NREL], USA funded studies under its Aquatic Species Program [ASP]. The programme discovered algae that had as much as 50% oil. For those with a technical bent of mind here’s a quote from an NREL PDF file: “Microalgae, like higher plants, produce storage lipids in the form of triacyglycerols [TAGs]. While TAGs could be used to produce a wide variety of chemicals, work at SERI focused on the production of fatty and methyl esters [FAMEs], which can be used as a substitute for fossil derived fuel… Although a number of algal strains were investigated for growth and lipid production properties, the best candidates were found in two classes, the Chlorophyceae [green algae] and the Bacilliarophyceae [diatoms].”

The goal was to produce biodiesel on a large scale with least use of arable land. Michael Briggs of the University of New Hampshire, has published a study titled, “Wide scale biodiesel production from algae”. Oil bearing algae could be grown in utterly unusable land such as in deserts. Here shallow ponds filled with brackish or salt water can sustain algae growth by photosynthesis of solar energy. There are admittedly technological problems like rapid evaporation losses and salt build up.

Assuming these can be solved, it was estimated that only about 10 million acres were required to meet all of USA’s transportation fuel needs. And Sonora desert alone has over 70 million acres where nothing can grow.[This is not to suggest, that all biodiesel production be centralised in one place. Far from it.] In contrast, 450 m. acres are used for farming and 500 m. more for grazing animals in the USA.

If that sounds too good to be true, wait until what Dr Isaac Berzin at the Massachusetts Institute of Technology [MIT] has to say. Before we get to his big idea, let’s pause a moment to learn what interested NREL in algae in the first place. They were looking for a way for sequester CO2 emitted by industries - and they stumbled upon biodiesel as a by-product. Berzin has combined both to demonstrate a very commercially viable opportunity.

He has set up a demonstration at a power station in Boston. Unacceptably high CO2 laden emissions are led into tanks growing algae. CO2 is absorbed and accelerates algae growth. What bubbles out to the atmosphere is acceptable by the standards of Kyoto Protocol.

Algae is harvested daily and squeezed for oil from which biodiesel can be produced. The remaining green pulp can produce ethanol. The Berzin system saves pollution control costs for power plants and in fact produces an additional profit. In this report, Berzin claims that “just one 1,000 megawatt power plant using his system could produce more than 40 million gallons of biodiesel and 50 million gallons of ethanol a year. That would require a 2,000-acre “farm” of algae-filled tubes near the power plant. There are nearly 1,000 power plants nationwide with enough space nearby for a few hundred to a few thousand acres to grow algae and make a good profit”. Here’s more information.

Hydrogen, another energy option for the future, is considered “perfect” by environmental purists. The reasons are not far to seek: it can be endlessly extracted from the atmosphere and when burnt it combines with oxygen and leaves nothing but water vapour. But costs of making hydrogen are prohibitive. There are also safety issues to be addressed. Most of all storing hydrogen is not easy or cheap. Before hydrogen can fuel vehicles, these hurdles have to be overcome.

The work of an Australian research team led by a scientist of Indian origin, Dr Sukhvinder Badwal, has a novel way of addressing these problems. According to this report, “CSIRO Manufacturing and Infrastructure Technology has developed a device the size of a small, domestic microwave oven that runs on mains power or from a solar panel to extract enough hydrogen per day from water, to power a family car for up to 150 kilometres.”

The process of course, is nothing but good old electrolysis but the appeal is in reliable, decentralised turn-key production of hydrogen -even at home- using any source of energy. This obviates hazardous and expensive transportation of hydrogen to refill gas stations.

In the end, the only pure energy source there is in this world,is what came first: solar. Its promise has seduced -and, exasperated- researchers for centuries. Problem is it is widely diffused and unevenly available, calling for concentration and storage systems.

It is not surprising that Australia takes the lead in harnessing two energy sources it has in abundance: solar and natural gas. The latter, though plentiful, is not dense enough to serve transportation needs. In an effort to harness both these to advantage, Australia’s CSIRO has installed 200 tracking mirrors to concentrate solar energy to a receiver in a tower, where temperatures of 1000 deg.C are reached.[Picture] Using that and water, natural gas is enhanced by up to 26%. CSIRO has christened this Solar Gas. It’s advantage is its higher energy density, that make it attractive for storage and use in vehicles.

As for land requirement to produce Solar Gas, figures quoted are even more astounding than those for algal farms. This report says: “...the solar tower now running at Newcastle is sufficiently efficient to generate, in theory, all of Australia’s electrical needs from a 50 sq km site located in the continent’s remorselessly dry and sunny desert zones.”

India with its solar advantage must begin its walk down these new paths for a secure energy future.

[Inputs for this story came from readers Lakshmi Narayanan and Kris Rallapalli]