6 lessons on zero-carbon energy systems from countries leading the way
6 lessons on zero-carbon energy systems from countries leading the way
Getting to a net-zero-carbon energy system is essential. It will be a major effort, one that requires significant investment in new low-carbon infrastructure, from renewable power plants to electric vehicles, efficient appliances and better-constructed buildings. While very few countries are on track, China, Costa Rica, Denmark, Ethiopia and the United Kingdom are further along than many others.
These countries are all over the globe at all levels of development. Some arrived where they are by intent; others were helped by geography or history. Yet they all reveal lessons about the net-zero emissions transition needed in all countries to avert the worst impacts of climate change.
How can countries achieve zero-carbon energy?
Energy production and use accounts for about three-quarters of global greenhouse gas emissions, making it the most important element of a net-zero emissions strategy for many countries. Three main strategies can help countries meet energy needs with zero-carbon emissions: optimize; electrify; and decarbonize. Essentially, all countries need to:
- Reduce energy use through improved efficiency (optimize);
- Shift energy demand to electricity and away from combustion of fossil fuels (electrify); and
- Shift entirely to zero-carbon technologies to generate electricity (decarbonize).
These strategies are needed in all the major energy-using sectors — buildings, transportation and industry — as well as in the power system.
Some countries are further along on these three strategies than others, as indicated by their improvements in energy intensity, degree of electrification of energy use, and portion of their electricity that comes from zero-carbon sources. China, Costa Rica, Denmark, Ethiopia and the United Kingdom have some of the best scores on these indicators in the most recent available data, or have made significant progress over the past few decades on two or more indicators.
These indicators alone do not tell the whole story of a country’s decarbonization path and needs, but because comparable data is available for all countries through the IEA and the World Bank, they make it possible to assess all countries in a consistent way. And because these are relative (percentage) indicators rather than direct measures of absolute emissions, countries’ energy-related emissions still could be rising even as they improve on these metrics.
This is currently the case for most rapidly growing economies — where energy demand is growing significantly — but not for many developed economies, where economic growth, energy use and emissions are decoupling. To achieve net-zero emissions, the improvements in these metrics in all countries will need to be large enough to overcome growing demand for energy services.
How are countries decarbonizing their energy systems?
There are at least six important factors behind these countries’ decarbonization:
- Investments in energy efficiency: China, Denmark, Ethiopia and the U.K. have decreased their energy intensity at an annual rate of 4 percent or better in recent years, a rate significantly above the global average of 2.3 percent. This indicates that they are improving the energy efficiency of their economies and reducing energy demand. China, Denmark and the U.K. have set energy efficiency targets and implemented a comprehensive suite of policies and investment programs to increase energy efficiency.
- Hydropower: In Costa Rica and Ethiopia, which get almost all their electricity from clean sources, hydropower has been the majority of generation from 1990 to the present. These original investments in hydropower were made before widespread concern for reducing carbon emissions, so the decisions likely were based primarily on the economics of harnessing low-cost, locally available resources. But these aren’t just legacy systems; both countries have invested in additional hydropower capacity as electricity demand has grown. Hydropower is similarly important in electricity systems in Brazil, Colombia and Kenya, which are also close to zero-carbon. Meanwhile, developing countries as a whole only get an average of 28 percent of their electricity from zero-carbon sources.
- Investment in non-hydro renewables: Many countries’ progress on electricity decarbonization is being driven by investment in wind, solar photovoltaics and geothermal. Costa Rica, Denmark and the U.K. all went from getting virtually none of their power from non-hydro renewables in 1990 to 20 percent or more by 2017. Kenya also has grown its capacity considerably, particularly geothermal. China’s renewables growth has been small as a percentage of its electricity needs, but huge in absolute terms, as it is now the largest market for solar and wind in the world.
Meanwhile, global progress on clean electricity has stalled, with the share of zero-carbon sources basically stuck at 30-35 percent since 1990. The past few years have shown an uptick in the zero-carbon share — mostly coming from new wind and solar, while the share of nuclear and hydro is shrinking — but progress remains slow compared to the urgency of getting to zero.
- Growing wealth and economic modernization correlate with electrification of the energy sector: China is among the countries with the strongest growth in and highest share of electricity use compared to total energy consumption. Nearly a quarter of its energy consumption is electricity, as opposed to other energy forms such as direct consumption of fossil fuels such as natural gas or oil, up from only 6 percent in 1990. Growth in the electricity share of energy can be seen in other countries that have experienced rapid economic growth and modernization, including India, Indonesia, Mexico, Turkey and the United Arab Emirates. Overall, electrification levels in other countries have been changing very slowly, with the global average moving from 15 percent to 20 percent since 1990, driven mainly by developing countries. Addressing this slow pace and making sure that electrification is reaching all end uses within each sector is imperative for decarbonization.
- Building electrification has been significant; transportation has lagged: Electrification by sector varies considerably. By far the greatest electricity market share and growth is in the buildings sector, in both residential and services buildings. Globally, electricity increased its market share from 19 percent of all building energy consumption in 1990 to 31 percent in 2017. The growth has been greatest in emerging economies (Brazil, China, Costa Rica, India and Indonesia), while lower-income countries and developed economies generally experienced less change. This correlates with the growth of consumer classes in emerging economies and their purchasing of more electric equipment and appliances (PDF), such as lighting, fans and air conditioners, and a smaller portion of households using firewood or other traditional biomass fuels. The services sector — which is more electrified in general — also grew in these economies.
In contrast, transportation is only around 0-1 percent electrified in most countries and has shown very little change over the past three decades. China is the only notable exception, nudging up to 3.4 percent from 1.6 percent over this time period. This makes sense, as China is also the for electric vehicles, but even it has a long way to go to a fully electrified transportation sector. While the pace of change in transportation may be quickening, this is only partially reflected in the most recent data from 2017.
- Direct commitments to clean, efficient energy and decarbonization: Costa Rica, Denmark and the U.K. have set economy-wide net-zero emissions targets for 2050. These commitments to full decarbonization build upon the decades of efforts that these countries already have made toward energy efficiency, renewable energy and sustainable development. More countries should follow their lead in setting explicit decarbonization targets.
Getting onto a pathway for decarbonization
Some countries are positioned particularly well for decarbonization. But that doesn’t mean that other countries can’t also lead, even if they haven’t yet built as strong a foundation through previous actions. By learning from the leaders, all countries can chart a course to a zero-carbon future.