By Joe Grant, Wiscasset
Battery-powered cars (BPCs) are becoming less glamorous as people realize that they do not produce power but rather are “storage devices” and require a lot of time and electrical power to charge. That, coupled with the self-igniting and resulting intense metal fires, and the tenfold increase in lithium prices in the last two years have taken the luster off BPC’s. Now, “The Greens” are pivoting to the vast and “almost free” hydrogen found in our lakes and oceans to power our cars – the “hydrogen dream”. As they state in all their literature, the only emission is water from the tailpipe. That, coupled with the recent announcement of the first net positive energy production from controlled fusion, leaves our green energy coalition plenty of information to confuse the public, while chanting “follow the science”. They will be promoting news and excitement of a pivot to hydrogen power as real life experience pops the BPC bubble. We will be seeing more articles like the one published several weeks ago in a Lincoln County newspaper planting the seed that, somehow, re-oxidizing hydrogen produces more energy than is used in its production. The article asks “Why were these clean (hydrogen) technologies neglected in the various stages of development for decades? Why was petroleum developed instead? Could it be because oil can be profitably sold but water cannot?” The following paragraphs attempt to answer these questions.Producing hydrogen by electrolysis is like charging a battery. Both use electricity to produce a chemical change that can be reversed to rerelease the energy. Starting with Hess’s law, also known as the law of constant heat summation, simply sum enthalpy (energy) changes during chemical reactions. Electrolysis of a mole of water takes 286 kilojoules of energy. Re-oxidizing the two grams of hydrogen produced by that electrolysis releases the same 286 kilojoules. Unfortunately, every step of the process adds inefficiencies. In the electrolysis process 20% to 30% of the energy is lost. Compressing and storing the hydrogen costs another 10% and another 30% is lost in the fuel cell when converting the hydrogen into electricity. When the losses are summed only 30% to 40% of the original energy is available to an electric motor. The thermochemical process used to produce hydrogen also obeys Hess’s law. Methane, CH4, by itself is a wonderful fuel. Burning a mole of methane produces 880 kilojoules of energy. A mole of methane used as a reactant in a thermochemical steam process produces 6 grams of hydrogen gas and 28 grams of CO (carbon monoxide) and requires an input of 206 kilojoules of energy. This is a highly endothermic process requiring a lot of heat. It is much cheaper, less complicated, and more efficient to burn the methane directly. It gets worse. Often the CO, produced in the hydrogen generating process, is burned to supply heat to the process resulting in a release of 44 grams/mole CO2. In that case, the net release of CO2 is significantly higher than the direct use of the methane due to the complexities and inefficiencies noted in the previous paragraph. Production, compression, storage, and the final retail sale of the quantities of hydrogen to power vehicles would require huge energy input to produce hydrogen from either process and would require a massive infrastructure and billions of dollars. We must reduce our carbon footprint, but we cannot spend billions of dollars on schemes that do not work, produce power at an exorbitant cost, are unreliable, or have a limited lifetime. We need to look at all our options, including the cradle to grave cycle, do a scientific and engineering analysis of the processes, then ramp up with a step-by-step plan. Maine people and businesses need reasonably priced and reliable power. We have to get this right.To reduce our reliance on fossil fuels we should start by increasing the efficiency of energy usage including LED lighting, heat pumps, insulation, and more efficient heating and cooling systems. Next would be the purchase of Canadian hydro power that is available, cheap, and green. In the longer term, bring nuclear power back to Maine. In 1990 Maine Yankee generated 6.0 billion kilowatt hours while supplying 27.6% of all Maine’s electricity at a production cost of about 2.5 cents per kilowatt hour. When compared to the apocalyptical projections of global warming the U.S. nuclear utilities have an impressive safety record. For those who say,” let’s wait for fusion”, that is decades and many billions of dollars in the future if it arrives at all. I still have my pristine May 1994, Vol.1 No.1 Cold Fusion magazine. It is a useful reminder to those thinking about rewriting the laws of physics or building a magnetic containment for a 270-million-degree Fahrenheit plasma.
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