By Darshan L. Goswami, M.S., P.E. Project Manager (Ret.) US Department of Energy
India’s next big export industry could be its sunshine, as game-changing technology makes it easier to generate, store, transport and deliver its energy as “Solar Fuels.”
Solar energy is a free source of renewable energy that is sustainable and totally inexhaustible. It is also non-polluting and does not emit any greenhouse gases while producing electricity. Most people are aware of solar photovoltaics that generate electricity and solar panels that produce hot water. Now experts have developed techniques to convert sunlight into “Solar Fuels.”
The process to create “Solar Fuels” essentially involves exposing water molecules to sunlight to separate hydrogen and oxygen in water and then combining the hydrogen with carbon dioxide to create liquid fuels. The generated hydrogen can also be condensed under pressure at very low temperatures into a liquid hydrocarbon Fuels (LH2), simple hydrogen gas, metal hydride, or conversion to methanol.
Another option is to combine the hydrogen with nitrogen to make ammonia. It is a technique that is well-established, and has been done on an industrial scale for nearly a century. Ammonia can be compressed into a liquid at much more moderate temperatures, and is relatively easy to transport.
This hydrogen can be used in much the same way as petrol and diesel, or it can be used in fuel cells to generate electricity. Turning sunlight into fuel would enable solar energy captured during the day to be stored, transported, and used when the sun’s not shining. The goal is to store sunlight in liquid form, conveniently overcoming the transient nature of sunlight. These “Solar Fuels” will allow all the advantages of conventional fossil fuels along with the environmental benefits of renewable energy — a key step in someday powering cars with the sun. Research in solar-derived liquid fuels, or solar fuels, aims to make a range of products that are compatible with our energy infrastructure today, such as gasoline, jet fuel and hydrogen. Imagine a solar panel, but instead of wires with electricity coming out of it, it would have a pipe carrying fuel that can power your vehicle.
Bill Gates recently launched Breakthrough Ventures, a $1 billion fund to invest in scientific discoveries that have the potential to deliver cheap and reliable clean energy to the world. Gates believes “Solar Fuels” has the potential to be an “energy miracle,” as it would solve several of the current challenges to renewable energy adoption and dramatic greenhouse gas emission reductions. Done economically, this represents a huge step toward solving the two outstanding challenges in shifting from fossil fuels to renewable energy: storing large amounts of energy for later use, and powering forms of transportation that cannot easily run on batteries. CSIRO recently announced the establishment of a pilot plant to test technology that can refine a 100% pure stream of hydrogen from gasified ammonia using a metal membrane. Australia and Japan signed a deal in January 2017 to ship liquid hydrogen in bulk from Victoria, in what will be a world first.
Producing Renewable Hydrogen fuel with solar Energy
Hydrogen itself isn’t actually a fuel — it’s an energy carrier. Hydrogen is regarded as the energy source of the future.
Hydrogen is produced by splitting water molecules into hydrogen and oxygen by the electricity-driven process electrolysis. The hydrogen is then condensed under pressure and at very low temperatures into a liquid, which can be used in much the same way as petrol and diesel, or it can be used in fuel cells to generate electricity. This hydrogen and oxygen produced thus are stored to be used by a fuel cell to produce electricity when no sunlight is available. It can be converted into transportable forms as “Liquid Hydrogen Fuel” for export.
The future of hydrogen is bright. Since it doesn’t emit carbon dioxide when it’s burned, hydrogen is potentially the ultimate source of clean energy. Australia is set to be the first to do the latter after signing a deal with Japan to ship liquid hydrogen in bulk from Victoria. Australia is opening up a whole new energy market by using hydrogen to export its solar power.
Hydrogen-fueled cars have the added advantage of potentially taking a far shorter time to refuel — as little as five minutes with compressed high pressure gas — compared to an electric vehicle, which might need longer time to recharge. Hydrogen can be used to store excess electricity at the grid, or even the individual household, level.
India is blessed with unlimited amounts of sun and has an enormous capacity to generate renewable energy compared to other countries. “Solar Fuels” have the potential to turn India into a renewable energy superpower. Solar fuel could be the key to meeting future demands for sustainable energy, with emerging technologies enabling us to harness and convert sunshine into an array of usable fuels.
Germany is rapidly scaling up R&D in technologies such as electrolysis, which uses electricity from solar or wind power, and then adds water to produce hydrogen (and oxygen). Japan has announced an energy plan that includes support for hydrogen fuel cells in homes, hydrogen fuel cell cars, large scale power plant generation, and industrial processes, which could account for 80% of its total energy needs. Saudi Arabia also has plans to export up to 10 gigawatts of Solar Fuels to Europe – as expressed by King Abdullah at a conference in Paris.
Indian government must begin to actively embrace the potential of hydrogen as a clean alternative fuel source — and export industry. This is a great opportunity for India to create a solar industry which is not limited to the scale of its electricity network but export their sunshine around the world. I can imagine India bottling and shipping sunlight as renewable hydrogen on an industrial scale, as at a similar stage as LNG in the 1970s, when technology allowed natural gas to be liquefied and transported.