Tag Archives: Alternative-Energy

Charlie Stross on the future of nuclear power

power_plantCharles Stross has made an interesting point on the view that there is only a very short supply of useable nuclear fuel:

firstly, the supply of known uranium deposits will only last 80-100 years if we don’t recycle it and start burning MOX. I’d like to note that today’s light water reactors are horribly inefficient — they only extract 3% of the available energy from their fuel before it is considered “spent” and reclassified as waste. If we use high burn-up reactors such as the EPR, we can get a whole load more energy out of the same amount of fuel. And if we use fast breeders and run a plutonium cycle we can convert U238 into Pu239 and burn that instead of U235: there’s 500 times as much U238 lying around.

Secondly, we haven’t even tried to build a thorium reactor yet, although we’ve got good reason to believe it would work — and thorium is considerably more abundant than uranium.

As I have mentioned before, nuclear really should be part of the future energy mix of any industrialised country. Renewables can provide a large chunk (depending on local availability) of our energy needs but that still leaves a gap that needs to be plugged with something reliable and non-carbon-dioxide emitting.

David JC MacKay has more on nuclear power in his excellent free online textbook Sustainable Energy – Without the Hot Air.

[image from christian.senger on flickr]

Testing spray-on solar cells

A microscopic sensor to detect toxins needs a power source.  Xiaomei Jiang and colleagues at the University of South Florida respond with an array of 20 polymer-based cells, each about the size of a 12-point lower-case letter O.

The polymer they selected has the same electrical properties as silicon wafers, but can be dissolved and printed onto flexible material. “I think these materials have a lot more potential than traditional silicon,” Jiang said. They could be sprayed on any surface that is exposed to sunlight — a uniform, a car, a house.”

The next step is to test the array with the sensors. The team hopes to generate 15 volts by the end of the year.

[Sun Spray by littleblackcamera]

Is Solar feasible – absolutely!

A Concentrating Photovoltaic array by Solfocus using mirrors to concentrate light onto a III-V photovoltaic
Earlier today TJ wrote a post about the possibility of solar power as an alternative fuel. Now I have to admit to having a vested interest in this field as recently I began work as a Solar Analyst for a renewable energy developer. I’ve spent the last six weeks conducting studies into every aspect of the solar market and its feasibility. Although some more outlandish technologies have been overstated, the future of solar is incredibly bright.

There are four main types of solar power on the horizon. Most people know about silicon photovoltaics, which are now reaching record efficiencies of 23%.

"Major discovery" could spark solar revolution

776px-SolarFachwerkhaus MIT scientists are touting a “major discovery” that will transfer solar power from a “limited, far-off solution” to “unlimited and soon.” (Via EurekAlert.)

Daniel Nocera, the Henry Dreyfus Professor of Energy at MIT and senior author of a paper describing the work that’s in the July 31 issue of Science, and Matthew Kanan, a postdoctoral fellow his lab, have created a new  catalyst that produces oxygen gas from water. When combined with another catalyst that produces hydrogen, their system can duplicate the water-splitting reaction that occurs during photosynthesis. Hydrogen and oxygen produced during the day while the sun is shining can be combined in a fuel cell at night when it’s not, solving the biggest problem with solar power–it doesn’t work when the sun doesn’t shine. Current methods of storing that energy are both too expensive and very inefficient.

Best of all, the new catalyst is made from abundant, non-toxic natural materials: it consists of cobalt metal, phosphate and an electrode, placed in water. When electricity runs through the electrode, the cobalt and phosphate form a thin film on it, and oxygen gas is produced. The catalyst works at room temperature and in neutral pH water, and is easy to set up.

Superlatives are being implemented to describe the discovery:

James Barber, a leader in the study of photosynthesis who was not involved in this research, called the discovery by Nocera and Kanan a “giant leap” toward generating clean, carbon-free energy on a massive scale.

“This is a major discovery with enormous implications for the future prosperity of humankind,” said Barber, the Ernst Chain Professor of Biochemistry at Imperial College London. “The importance of their discovery cannot be overstated since it opens up the door for developing new technologies for energy production thus reducing our dependence for fossil fuels and addressing the global climate change problem.”

Nocera hopes that within 10 years the system will be available to homeowners, allowing them to power their homes during the day with photovoltaic cells and use hydrogen and oxygen produced with the day’s excess energy to power their homes at night.

The net result?

Electricity-by-wire from a central source could be a thing of the past.

(Photo by T

Germans putting CO2 underground

Carbon sequestration or carbon capture and storage (CCS) is an enticing possibility for those who like their global CO2 levels below 390 ppm but aren’t too keen on nuclear power.

sa-megetThe basic idea is to carry on burning fossil fuels for energy, but instead of venting the waste CO2 into the atmosphere, bury it underground. Now CO2SINK, a European research project, have created the first underground carbon dioxide storage site at Ketzin, near Berlin:

It will pump up 60,000 tonnes of the greenhouse gas into porous, salt water-filled rock at depths of more than 600 metres (656 yards) over the next two years, the centre said.

This obviously won’t solve all the problems. After all it is probable that our fossil fuels will run out at some point. “Clean” fossil fuels might provide a useful stopgap before we decide on our long term energy mix.

[story via PhysOrg][image from Jacob Botter on flickr]