Utility Week

28 | 3RD - 9TH MAY 2019 | UTILITY WEEK Customers Market view T he hard realities of an energy system based on renewables will soon be with us, causing far more problems than are realised. Renewables don't offer a quick fix, and we need to get the transition from "black" to "green" technologies right to avoid some hugely costly – and ridiculous – anomalies. While global carbon dioxide emissions flattened out between 2014 and 2016, they started to increase again in 2017 (rising by 1.6 per cent) and are predicted to have been up 2 per cent in 2018. The main causes have been identified as being the increasing use of oil and gas, and the ongoing use of coal by developing countries in particular in support of their economic growth. There is mounting pressure on governments to move more quickly and be more radical in their response. Formal revisions of national emis- sions reduction targets will be made in 2020. In the meantime, the UN is subject to active international campaigns to introduce much tougher carbon targets. We can all agree that the future needs to be based on sustainable energy technologies. But there needs to be a more open-eyed and systematic evaluation of the full costs – both financially and in terms of carbon footprint – of different energy generation options. Fundamental to the issue is the whole-life costs of introducing more renewables. For example, taking into account the full range of environmental impacts from creating a new renewables infrastructure, the min- ing and industry involved in supplying vast amounts of minerals and metals. Most significantly of all, calculations need to include costs of creating buffer stor- age. All we're seeing at the moment is the carbon emission benefits from introducing renewables as a minority of energy supplies, all done at a reasonable cost. But this will quickly change when renewables start to form a majority of energy supply – because, suddenly, supplies will be at the mercy of the intermittent nature of renewables and the demand for storage. There are, as yet, no technological answers to the need for mass battery storage. It's been estimated that the UK alone would require all the available resources of lithium on the planet to provide the necessary battery buffer. Whatever tech- nologies and methods are used will mean large increases in costs to energy customers. Other cost issues need to be considered, such as the actual carbon footprint involved in the increased use of natural gas by many developed economy governments as a means of reducing carbon emissions. The process in itself is cleaner, but what about the potential for pipeline leakages of methane (which has a warming effect that's estimated to be 80 times that of carbon dioxide)? In the US between 2010 and 2017, the natural gas network leaked 17.5 billion cubic feet of methane, constituting a similar impact to a large coal-fired power station for a year. Leaks have reached a level of 2.3 per cent – and if they reach 3 per cent then the study claims there will have been no envi- ronmental benefits at all from moving from coal to gas power plants. Alternatives to conventional power sta- tions can involve more complex footprints. The UK is one of the world's largest import- ers of wood pellets – coming mostly from the US, Canada and Latvia – for use as bioenergy feedstock. Wood-burning power plants like this have traditionally, and misleadingly, been counted as being "zero carbon". Being more realistic about the whole costs of renewables isn't an attempt to undermine their long-term importance. But it's critical for the transition period that governments and their policymakers understand the full picture and the necessary compromises and avoid making a headlong rush for renewa- bles without considering the sustainability of the transition. In particular that means an open mind when it comes to what are the most effective and workable transition technologies. The prime example is carbon capture and storage (CCS). CCS has tended to be marginalised in recent years due to the obvious addi- tional costs and loss of efficiency in power generation. But in this clear-eyed context, CCS is a workable option in terms of bal- ancing financial costs and meeting carbon reduction targets. Rather than focusing on the nega- tive, frightening messages around climate change, there are many reasons for feeling optimistic, and because of the new CCS tech- nologies in particular. Our recent research, for instance, has demonstrated the real potential for reducing global carbon diox- ide emissions by 8 per cent just through the use of CCS to decarbonise the iron and steel industry economically, hitting 2050 carbon targets by 2030. This would not be possible if there was a sole reliance on renewables. Introducing more CCS, just as one transition technology, will create jobs, encourage more investment, and allow a genuinely sustain- able basis for a future of renewables. Vasilije Manovic, professor of carbon systems engineering, Cranfield University What is the carbon footprint of renewables? Renewables may not be the panacea to emissions reduction that many assume. Vasilije Manovic says a clear-eyed assessment of the whole-life carbon footprints of all available solutions would carve out a major role for carbon capture and storage. Gas pipeline leakage is an issue

• Cover