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Practical alternative
Greg Harris poses the question: Why hydrogen and fuel cells?
Let’ s start with the basic assumption that climate change is real and already happening, and the world needs to stop producing CO 2 to avoid a climate crisis. Add in that to save lives in our busy cities, we need to stop the production of harmful pollution such as NOx. That means the engine technology that we have used for more than a century and is still used today in most motive applications( and many stationary applications) must change. Of course, this change is already taking place, and in the UK and most developed countries, the use of batteries to power cars, electric buses and many other areas continues to increase year-on-year. If the electricity that is used is green, then there is no CO 2 or other pollution created during use of that vehicle.
So, the obvious questions are, why isn’ t all focus on battery powered vehicles and batteries to replace engines in all other use cases, and why isn’ t the uptake of batteries for these applications moving faster? From a technical point of view, the biggest issue is the relatively low energy density of today’ s batteries – they are too heavy and take up too much space to meet the longer distance and heavier payload requirements of larger vehicles. The slow speed to re-charge batteries( even ultra-fast charging takes tens of minutes) compounds the energy density issue. Other issues which are slowing the pace of battery uptake are the cost per kWh, the relatively short life before replacement, challenges in( economic) recycling, safety, and supply chain issues( where all the materials come from and how much is available).
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