The Vector: Potential Energy Game-Changers

There is a lot of research and system development going on in the renewable energy field right now. Vector gives you a taste of some very different technologies that could – some day – change the economics of renewable energy generation.

Two of our research technologies are nano-materials. Working at molecular level, scientists are creating new materials with extremely useful properties. Once the materials have been designed, they can be scaled up for mass applications.

Our third example concerns developments in tidal power, one of the few sources of renewable energy that is as reliable as clockwork – in fact, as reliable as the orbiting moon. The moon’s gravitational pull is the source of tidal power.

Harvesting hydrogen from artificial photosynthesis

Natural photosynthesis has harvested solar energy for millions of years, sustaining our food sources and creating the fossil fuels we currently depend on. A team of MIT nanotechnology researchers has found a novel way to mimic the process by which plants use the power of sunlight to split water and make chemical fuel to power their growth.  The ultimate aim of the MIT team is to harvest hydrogen fuel from the splitting of hydrogen and oxygen in the water molecules in a self-sustaining system powered by the sun.

The MIT team led by Professor Angela Belcher engineered a common (harmless) bacterial virus called M13 so that it would attract and bind with molecules of iridium oxide (as a catalyst) and zinc porphyrins (a natural pigment).  The viruses line the pigments up to act as antenna to capture light and then transfer the energy down the length of the virus, like a wire.

The virus proved a very efficient harvester of light- initially just for short periods of time. But by encapsulating the wire-viruses in a microgel the team kept them stable and efficient for long periods.

Currently, the hydrogen atoms from the water get split into their component protons and electrons. The team are working on a second stage that would combine these back into hydrogen atoms for energy harvesting.

Belcher expects to have a prototype device that can carry out the whole process of splitting water into oxygen and hydrogen, using a self-sustaining and durable system, within two years.

But that is not the end of the road. While praising Professor Belcher’s achievement as a clever piece of work that addresses one of the most difficult problems in artificial photosynthesis, Professor Thomas Mallouk, from Pennsylvania State University, also outlined the challenges ahead:

“There is a daunting combination of problems to be solved before this or any other artificial photosynthetic system could actually be useful for energy conversion.”  To be cost-competitive with other approaches to solar power, he says, the system would need to be at least 10 times more efficient than natural photosynthesis, be able to repeat the reaction a billion times, and use less expensive materials.  “This is unlikely to happen in the near future.”

Taking energy-cost out of heat transfer

Across the world we consume vast quantities of energy extracting heat to cool environments (refrigerators, air conditioners, laptop fans and engine cooling systems, for instance) or adding heat to environments. Heat transfer is an energy-hungry business.

Researchers at Oregon State University and the Pacific Northwest National Laboratory have discovered a new way to apply nanostructure coatings to make heat transfer far more efficient. These coatings can remove heat four times faster than the same materials before they are coated, using inexpensive materials and application procedures.

The discovery has the potential to revolutionize cooling technology.

“For the configurations we investigated, this approach achieves heat transfer approaching theoretical maximums,” said Terry Hendricks, the project leader from the Pacific Northwest National Laboratory.

The heat transfer surfaces are coated with a multi-textured surface that looks almost like flowers. Water was boiled during the experiments to test the heat transfer characteristics, but it would work as well or better with other liquids. The coating of zinc oxide on aluminum and copper substrates is inexpensive and could affordably be applied to large areas.

Tapping into Moon power

During August the world’s largest and most powerful tidal turbine was installed on a subsea berth below 35 meters (over 70 feet) of water at the European Marine Energy Centre in the Orkney Islands, North of Scotland.

The tidal turbine's blades are 18 meters in diameter

The AK1000 tidal turbine is 22.5 meters tall and weighs 1,300 tonnes.  It needed over 1,000 tonnes of ballast blocks to secure the structure with its twin set of 18 meter diameter rotors. It creators, Atlantis Resources Corporation, are investing around $25 million in building, installing and testing the massive undersea structure. Because of the sweeping tides it will face, the turbine’s design is simple and robust. It has to withstand one of the toughest environments on the planet. The slow moving blades (6 to 8 revolutions per minute) mean that it will present very little danger to wildlife.

Atlantis designed AK1000 to win a bid in Britain’s Pentland Firth marine energy project, the world’s first industrial-scale wave and tidal energy program – with plans for at least 700 MW of capacity by 2020.

This is a significant step towards proving that tidal power is the most exciting  emerging technology in the renewable power generation mix, according to Atlantis CEO, Tim Cornelius:

“Atlantis has proven that with adequate planning, appropriate resource and the adoption of technology developed over the past 20 years in the oil and gas industry, commercial scale turbines can be installed safely and cost effectively, even in the most challenging of open ocean locations.”