Klimawandel: Techno­logie und Atom­kraft als Lö­sung

In einem Beitrag für FOREIGN AFFAIRS beschreiben führende amerikanische Wissenschaftler den Weg zur CO2-neutralen Welt. Es ist ein nüchterner Beitrag, der sich in meinen Augen wohltuend von der Diskussion hierzulande abhebt:

  • „The good news is that technological progress can make it much easier to clear them by driving down the costs of action. In the decades to come, innovation could make severe cuts in emissions, also known as ‘deep decarbonization,’ achievable at reasonable costs. (…) In a few sectors, especially electric power, a major transformation is already underway, and low-emission technologies are quickly becoming more widespread, at least in China, India, and most Western countries. The right policy interventions in wind, solar, and nuclear power, among other technologies, could soon make countries’ power grids far less dependent on conventional fossil fuels and radically reduce emissions in the process.“ – bto: Das klingt zunächst einmal gut.
  • „Technological progress in clean electricity has already set off a virtuous circle, with each new innovation creating more political will to do even more. (…) In most other high-emission industries, however, deep decarbonization has been much slower to arrive. In sectors such as transportation, steel, cement, and plastics, companies will continue to resist profound change unless they are convinced that decarbonization represents not only costs and risks for investors but also an opportunity to increase value and revenue. (…) Unless governments and businesses come together now to change that—not simply with bold-sounding international agreements and marginal tweaks such as mild carbon taxes but also with a comprehensive industrial policy—there will be little hope of reaching net-zero emissions before it’s too late.bto: Woher die Mittel dafür kommen sollen, wird elegant ausgeblendet.
  • „From today’s vantage point, no single domain offers greater opportunities for deep decarbonization than electric power. The use of electricity does not increase or reduce emissions in itself; electricity delivers energy that may or may not be clean depending on how it was generated. An electric car, for instance, doesn’t do much good against global warming if all the electricity comes from conventional coal plants. Still, electrifying the economy—in other words, designing more processes to run on electricity rather than the direct combustion of fuels—is essential. This is because, compared with trying to reduce emissions in millions of places where they might occur, it is far easier and more efficient to reduce emissions at a modest number of power plants before distributing the clean electricity by wire. Today, Western economies convert about 30 percent of their energy into electric power. If they want to get serious about decarbonization, that fraction will need to double or more.“ – bto: Also muss man von einem höheren Strombedarf ausgehen. Bei uns sieht man in der Einsparung von Strom einen wesentlichen Hebel. Deutschland soll verzichten, so der Wunsch der Politik, auf die Idee käme man in den USA wohl nicht.
  • „Overall, transportation accounts for 27 percent of global energy use, and nearly all of it relies on oil. The car industry has had some success in changing this: the latest electric vehicles rival high-end conventional cars in performance and cost, and electric cars now make up around eight percent of new sales in California (although only 1.3 percent nationwide) and nearly 56 percent in Norway, where the government offers massive subsidies to buyers. With improved batteries, heavier-duty vehicles, including buses and trucks, could soon follow.“ – bto: Skeptiker bringen hier das Gewicht ins Spiel. Das spricht dann eher für Wasserstoff.
  • „Besides transportation, the most important electrification frontier is heating—not just in buildings but as part of industrial production, too. All told, heating consumes about half the raw energy that people and firms around the world use. Of that fraction, some 50 percent goes into industrial processes that require very high temperatures, such as the production of cement and steel and the refining of oil (including for plastics). These sectors will continue to rely on on-site fossil fuel combustion for the foreseeable future, since electricity cannot match the temperature and flexibility of direct fuel combustion. Yet in other areas, such as lower-temperature industrial processes and space heating for buildings, electrification is more practical. Heat pumps are a case in point: whereas conventional heaters work by heating up indoor air, heat pumps act like reversible air conditioners, moving heat (or, if necessary, cold) indoors or outdoors—a far more efficient approach.“ – bto: Wir wissen, dass dies funktioniert, aber wir brauchen trotzdem ein Back-up.
  • „Electrification, of course, will not on its own reduce emissions by much unless the power grid that generates and distributes the electricity gets cleaner, too. (…) China, for instance, has swapped out aging coal plants with newer, more efficient ones, cutting emission rates in the process. The United States, for its part, has cut down on its emissions thanks to innovations in horizontal drilling and fracking that have made it economically viable to extract shale gas. In 2005, when this technology first became commercially relevant, coal accounted for half of all the electricity produced in the United States; today, coal’s share is down to one-quarter, with much cleaner and inexpensive natural gas and renewables making up the difference.“ – bto: Hätten wir statt der Atomkraftwerke die Kohlekraftwerke stillgelegt, sähe es bei uns auch besser aus.
  • „In theory, fossil fuels could still become much cleaner, even nearly emission free. This could be possible with the help of so-called carbon capture and storage (CCS) technologies, which capture the carbon dioxide emissions created by industrial processes and pump it safely underground. In practice, investors have remained wary of this approach, but in both the United States and some European countries, recently introduced subsidies are expected to unleash a wave of new CCS projects in the years ahead. One CCS scheme, currently being tested by a group of engineering and energy firms, completely rethinks the design of power plants, efficiently generating electricity from natural gas while capturing nearly all the carbon dioxide produced in the process at little extra cost. In regions where natural gas is cheap and abundant, this technology could be a game changer.“ – bto: ebenso wie die Idee vom grünen Diesel, der so hergestellt wird. Bei uns wiederum aus ideologischen Gründen verboten.
  • „To prevent the world from warming further will require much more focus on technologies that have essentially zero emissions, such as wind, solar, hydroelectric, and nuclear power, in addition to CCS, if it proves commercially scalable. According to the United Nations’ Intergovernmental Panel on Climate Change, these low-carbon technologies would need to generate 80 percent of the world’s electricity by 2050 (up from about one-third today) in order to limit warming to two degrees Celsius above preindustrial levels.“ – bto: Hier wird die Atomkraft ausdrücklich dazugerechnet. Das ist richtig so.
  • „Renewables, in particular, will play a central role. Thanks to decreases in the cost of wind and solar power equipment—and thanks to a mature hydroelectric power industry—renewable energy already accounts for over one-quarter of global electricity production. (Nuclear provides another ten percent.) In the United States, the cost of electricity from large solar farms has tumbled by 90 percent since 2009, and wind energy prices have fallen by nearly 70 percent—and both continue to drop.“ – bto: dank der großzügigen Anschubfinanzierung der deutschen Stromkunden. Das haben wir doch toll gemacht!
  • „(…) the main challenge is no longer to make renewables cheap; it is to integrate them into the power grid without disruptions. To avoid blackouts, a power grid must align supply and demand at all times. Energy output from wind and solar plants, however, varies with the weather, the season, and the daily rise of the sun. The more a power grid relies on renewables, then, the more often the supply will not match the demand. In the extreme, extra power must be dumped—meaning that valuable capital and land were used inefficiently.“ – bto: Das ist genau das, was bei uns massiv passiert und zu den hohen Energiepreisen führt.
  • „To be less vulnerable to such shocks, utility companies will need to expand the size of their power grids, so that each can draw on a larger and more diverse array of energy sources. In order to deal with excess supply from renewables—a condition that will become much more frequent as the share of renewables rises—they must also create incentives for users to vary their demand for power more actively and find ways to store surplus electricity on a much larger scale. Today, nearly all bulk storage capacity takes the form of hydroelectric pumps, which store electricity by moving water uphill and recovering about 80 percent of the power when it flows back down. In the years ahead, soaring demand for electric vehicles will drive down the cost of lithium-ion batteries; those batteries could become an affordable way to store energy at the grid level, too. And as the need for storage increases, even cheaper methods may come on the market.“ – bto: Diese Batterien mögen geeignet sein, tageszeitliche Schwankungen auszugleichen. Es steht zu bezweifeln, dass es genügen wird, um damit auch jahreszeitliche Schwankungen auszugleichen. Und die können unangenehm sein.
  • To better integrate renewables, policymakers can also rely on the strategic use of another zero-emission technology: nuclear energy. Although most efficient when running flat out 24 hours a day, nuclear power plants can also operate flexibly to cover the supply gaps from wind and solar power. Some of France’s nuclear reactors, for instance, already cycle from about one-quarter to full power and back again, sometimes twice a day, to compensate for fluctuations in the supply and demand of renewables.“ – bto: Die sichere und günstige Stromversorgung könnte sich noch als Frankreichs strategischer Vorteil in den kommenden Jahrzehnten herausstellen.
  • „Independent of renewables, nuclear power already contributes massively to cleaner grids. Every year, some 440 operational nuclear reactors account for lower global carbon dioxide emissions of an estimated 1.2 billion metric tons. In the United States, research suggests that keeping most existing nuclear plants open would be far less expensive than many other policy options. In fact, most countries would do well to expand their nuclear power even further to cut back on their emissions. In the West, however, major expansions are not on the horizon: public opposition is strong, and the cost of building new reactors is high, in part because countries have built too few reactors to benefit from the savings that come with repetition and standardization. Yet in other parts of the world—especially China and South Korea, which have more active nuclear power programs—the costs are much lower and public opposition is less pronounced.“ – bto: was einen entsprechenden Wettbewerbsvorteil mit sich bringt.
  • „When it comes to the precise technological makeup of a future decarbonized economy, expert opinions diverge. Engineers and economists, for the most part, imagine solutions that bundle several approaches, with both CCS and nuclear power acting as important complements to renewables. Political scientists, on the other hand, tend to see a bigger role for renewables—one of the few areas in energy policy that usually garners support from across the ideological spectrum, including in the United States. Yet even this rather popular solution can prove divisive. Fierce debates rage over where to locate generators such as wind turbines, including among putative environmentalists who support the technology only if they don’t have to look at it. (…) The same issue arises when it comes to power lines: making the most of renewables requires longer, more numerous power lines that can move renewable power wherever it will be needed, but public opposition can make such grid expansions a bureaucratic nightmare.“ – bto: auch aus Deutschland bekannt. Wichtig also, die Wissenschaftler sind für einen Mix an Instrumenten, die „politischen Wissenschaftler“, die vor allem hierzulande dominieren, sind hingegen dogmatischer. Sie wollen mit dem Kopf durch die Wand und fokussieren auf Erneuerbare, ohne eine Lösung für die Speicherfrage zu haben.
  • „Hydrogen, in particular, could serve much the same function as electricity does now in carrying energy from producers to users—and it offers crucial advantages. It is easier to store, making it ideal for power systems dependent on ever-fluctuating supplies of renewable energy. And it can be burned—without producing any new emissions—to generate the high levels of heat needed in heavy industry, meaning that it could replace on-site fossil fuel combustion in sectors that are hard to electrify. Hydrogen (either in its pure form or mixed with other chemicals) could also serve as liquid fuel to power cars, trucks, ships, and airplanes. A zero-emission economy could integrate the two carriers—electricity and hydrogen—using each depending on its suitability for different sectors.“ – bto: Ja, auch das leuchtet mir ein, vor allem wenn wir dann eine entsprechende Energiedichte hinbekommen.
  • „The technology needed to turn hydrogen into an energy carrier already exists in principle. One option is to break up (or electrolyze) water into its constituent elements, hydrogen and oxygen. The hydrogen could then be stored or transported through the natural gas pipeline networks that already string across all advanced economies. Once it reached its user, it would be burned for heat or used as an input for a variety of chemical processes. So far, this approach is too expensive to be viable on a large scale, but growing investment, especially in Europe, is poised to drive down the cost rapidly.“ – bto: Da könnten wir doch erneut die Welt retten, indem wir das solange subventionieren, bis es sich für alle lohnt. Produziert wird das dann wieder in China.
  • „Agriculture’s biggest potential contribution, however, lies belowground. Plants that engage in photosynthesis use carbon dioxide from the air to grow. The mass cultivation of crops that are specially bred to grow larger roots—a concept being tested on a small scale right now—along with farming methods that avoid tilling the soil, could store huge amounts of carbon dioxide as underground biomass for several decades or longer.“ – bto: Auch das stimmt.
  • „The details will vary by sector, but the common thread is that governments must directly support fledgling technologies. That means tax credits, direct grants, and promises to procure pioneering green products even if they are more expensive than their conventional alternatives. These steps will ensure that new low-emission products in sectors such as cement, steel, electricity, plastics, and zero-carbon liquid fuels can find lucrative markets.“ – bto: und natürlich Protektionismus, um die Industrie zu schützen.
  • „Setting bold goals can help, but new technological facts on the ground—sped along by active industrial policy and international cooperation—are what will transform the politics and make deep decarbonization a reality. Change will be slower than advocates and scientists would like. But it will accelerate if the leaders most willing to act on climate change stop moralizing and start seeing deep decarbonization as a matter of industrial engineering.“ – bto: leider hierzulande nicht in Sicht.

foreignaffairs.com:”The Paths to Net Zero”, Mai/Juni 2020