21 November 2016, Yale Climate Connections, Fuel Cells: Promising, but struggling to catch on. Fuel cells are efficient, generate clean electricity, and they run around the clock. So why aren’t we using them on a mass scale? Fuel cells have been the next best clean-energy thing for, well, a long time. The byproducts of that reaction are heat and water. The heat can be recycled into the fuel cell itself and/or used for external heating and cooling – generally referred to as combined heat and power. That makes stationary fuel cells – the kind used for electricity, as opposed to ones used in vehicles – extremely efficient and as clean an energy source as solar and wind.A technology with roots in the 1800s and modern-day use in every NASA-manned space flight from Apollo through the end of the space shuttle program, fuel cells just kind of look like a big box. Inside, they electrochemically combine hydrogen and the oxygen from ambient air to create electricity. But because the hydrogen source for most fuel cells comes from natural gas, they are generally not considered renewable, leaving them in an environmental limbo. Read More here
Category Archives: New Energy Sources
15 November 2016, Energy Post, Biofuels turn out to be a climate mistake. Biofuels are usually regarded as inherently carbon-neutral, but once all emissions associated with growing feedstock crops and manufacturing biofuel are factored in, they actually increase CO2 emissions rather than reducing them, writes John DeCicco of the University of Michigan. According to DeCicco, biofuels are actually more harmful to the climate than gasoline. Ever since the 1973 oil embargo, U.S. energy policy has sought to replace petroleum-based transportation fuels with alternatives. One prominent option is using biofuels, such as ethanol in place of gasoline and biodiesel instead of ordinary diesel. Transportation generates one-fourth of U.S. greenhouse gas emissions, so addressing this sector’s impact is crucial for climate protection. Many scientists view biofuels as inherently carbon-neutral: they assume the carbon dioxide (CO2) plants absorb from the air as they grow completely offsets, or “neutralizes,” the CO2 emitted when fuels made from plants burn. Many years of computer modeling based on this assumption, including work supported by the U.S. Department of Energy, concluded that using biofuels to replace gasoline significantly reduced CO2 emissions from transportation.Biofuels are far from inherently carbon-neutral Our new study takes a fresh look at this question. We examined crop data to evaluate whether enough CO2 was absorbed on farmland to balance out the CO2 emitted when biofuels are burned. It turns out that once all the emissions associated with growing feedstock crops and manufacturing biofuel are factored in, biofuels actually increase CO2 emissions rather than reducing them. Read More here
20 July 2016, CSIRO Blog, Supersonic magnesium. It’s used to make our smartphones and cars, and it makes our fireworks go off with a brilliant bang. It’s the third most commonly used structural metal and comprises 2% of Earth’s crust. We are of course talking about magnificent magnesium. Why do we think it’s so magnificent? Well, when magnesium is mixed with other metals it makes stable, super-strong alloys. Not only are these alloys used in our mobile phones and laptops, they are also highly sought after by car manufacturers who are turning to the metal as a solution for making lightweight, low-emission vehicles. Australia is sitting in the driver’s seat to deliver new, improved, ‘supersonic’ magnesium metal and take advantage of our vast untapped reserves of magnesite. So we’ve decided to take the wheel and develop an innovative technology, known as MagSonic, which produces magnesium using up to 80 per cent less energy and up to 60 per cent less carbon dioxide emissions than traditional processes. The process involves heating magnesia (magnesium oxide) with carbon to extreme temperatures to produce magnesium vapour and carbon monoxide. The gases are then passed through a supersonic nozzle – similar to a rocket engine – at four times the speed of sound. This cools the gases in milliseconds, condensing and solidifying the magnesium vapour to magnesium metal. Read More here
16 May 2016, Renew Economy, Vanadium: the ‘beautiful metal’ that stores energy. An unheralded metal could become a crucial part of the renewables revolution. Vanadium is used in new batteries which can store large amounts of energy almost indefinitely, perfect for remote wind or solar farms. And what’s more there is loads of the stuff simply lying around in industrial dumps. Don’t let the dumpster diving put you off – never mind gold or silver, vanadium may just be the most beautiful metal of all. It’s the 22nd most abundant element in the Earth’s crust, though it’s rarely found naturally in its metallic form. Instead, vanadium can be found in more than 100 different minerals. Once extracted and dissolved in water, various forms of vanadium turn into bright, bold colours. It’s even named after “Vanadis”, the old Norse name for the Scandinavian goddess of beauty, Freyja. Vanadium is not only beautiful, but also strong. Adding small percentages of it creates exceptionally light, tough and more resilient steel alloys. Henry Ford was the first to use it on an industrial scale, in the 1908 Model T car chassis, and today the vast majority of vanadium is used in structural steel, mainly to build bridges and buildings. Vanadium flow batteries The unique properties of vanadium make it ideal for a new type of batteries that may revolutionise energy systems in the near future – redox flow batteries. Batteries store energy and generate electricity by a reaction between two different materials – typically solid zinc and manganese. In flow batteries, these materials are liquid and have different electric charges. Both are pumped into a “cell” where the electric current is generated. A tiny membrane separates the two liquids, so they are able to react but don’t come into direct contact. Vanadium is used in these batteries as it can convert back and forth from its various different states, which can carry different positive charges. As only one material is used, the risk of cross contaminationis eliminated. The liquids have an indefinite life, so the replacement costs are low and there are no waste disposal problems. Also, the battery is extended to a potentially infinite lifetime. Watch ‘How the Vanadium battery works’ video here In flow batteries, the energy production and capacity are independent. Energy is stored in tanks, whereas the capacity depends only on the amount of liquid stored. This provides a great design flexibility that other batteries do not allow. They are also safer, as the two liquids don’t mix causing a sudden release of energy. Even President Obama is impressed. Read More here