Solid-Oxide fuel cells (SOFC)
According to developers, solid oxide fuel cell technology would be among the most in demand. Researchers at Harvard School of Engineering and Applied Sciences, headed by Sriram Ramanathan are working on solid oxide fuel cells to replace fossil fuels with pollution-free fuel cells. They use abundant natural resources at low cost to create small devices working at lower temperatures.
One major hurdle in current all-ceramic thin-film SOFC fuel cell technology has been use of very expensive platinum electrodes. Harvard team developed platinum-free low cost and more reliable SOFC. Conventional technology needed very high temperatures between 800-10000C. New technology SOFC works at 5000C and efforts are on to reduce the temperature near 3000C.
These fuel cells will run on methane, abundantly available at low cost, and useable at low temperatures. Hydrogen was found to be costlier than methane for fuel cells. These SOFC may be usable both for stationary as well as transport applications if temperatures are on lower side, and present target of 3000C may make it possible.
Downside of SOFC is their water emission as waste, which may not be good in a number of applications. Since low temperature operation is a long way, there no immediate possibility of their use in computers and mobile phones. The drawbacks are expected to be overcome and SOFC technology is likely to be in extensive use in near future.
Portable fusion reactors
Lockheed Martin has been trying to create portable compact fusion reactor (CFR) since past five years. They aim to create a reactor to power a small city. Researchers created a small cylindrical reactor in a space of 1m × 2m and created a confined plasma, heating Deuterium gas with RF energy (a form of non- ionizing electromagnetic radiation). Plasma is kept stable using magnetic field. In May 2016, there were good number of investment proposals, and they expect projects as large as 100 MW in ten years.
Recently China has reported creating artificial sun, using fusion reaction and reaching temperatures six time that at the core of the sun. When fully developed, they expect to get energy and light from this high temperature plasma source in earth orbit on continuous basis to cover huge requirements for the country.
Alga is looked upon as a viable perennial source of fuel. Alga are mega oil producers, capable of producing 1000-5000 gallons oil per acre, not possible by any crop. Oil from algae is similar to vegetable oil and can be converted to oil using existing technology. Algae do not compete with food sources for land, can be grown even in salty conditions and they also treat polluted waters. There is still some way to go, but researchers feel this can be promising fuel source of future. If and when the systems are in place, there will be good energy available from algae, which at the same time, will help remove water pollution.
A German firm Rawlemom has created a spherical sun power prototype, called Beta.ray. The yield is expected twice that of solar panel in a much smaller surface area. Design is fully rotational, and is suitable for inclined surface, walls of buildings, or anywhere where it is open to sky. This can also be used for car charging stations.
There are other developments also going on, and we can expect new exciting technologies in near future forming a part of renewable energies.
Please Note: The article is a continuation of the Part 1 carried in the Electrical India July 2020 issue.
B.Tech. Hon. (Elec.), IIT(Bom); F.I.E.