Not many people know this – yet – but ammonia is looking like being the best means by which wind and solar power can provide ‘firm’ power – that is ensure continuous supply of energy demand from renewable energy 100 per cent of the time. Ammonia, in this system, acts as an energy carrier for hydrogen produced from water which has been electrolysed – split into hydrogen and oxygen – by renewable electricity (mainly wind or solar). The hydrogen can be more or less simultaneously combined with nitrogen from the atmosphere to produce ammonia. The ammonia can be stored, and when needed, it can be burned in conventional-style turbines/engines or used in specially designed fuel cells to generate electricity when required. Currently much conventional wisdom has it that batteries are only the main means of storing renewable energy. Indeed batteries are very good for evening out balances in daily production and consumption of electricity – so peak demand can be reduced and the amount of firm power reduced. But we also need firm power for those days – under a 100 per cent renewable energy system – when there is little wind or sun. This is where ammonia comes in as a potentially better option for providing firm power. It is not a question of either batteries or ammonia, but simply that they can perform different functions providing short term and longer-term storage respectively. Ammonia (used as a hydrogen energy carrier) has a great advantage over hydrogen itself in that it can be stored much more easily than hydrogen. Ammonia is already stored for lengthy periods whereas long term storage of hydrogen requires development of the use of caverns or depleted gas fields.
Dave Toke’s Blog 24th Nov 2019 read more »