Heute kümmern wir uns wieder um die Energiewende. Zunächst zum Wind. Hier sind die Bürger mittlerweile aufgewacht und haben nun die Nase von den rotierenden Stahlkolossen vor ihren Schlafzimmern gestrichen voll. Daniel Wetzel griff das Thema am 27. Juli 2016 in der Welt auf
In Deutschland dreht sich der Wind gegen die Windkraft
Sturm auf die Windräder: Menschen in Deutschlands ländlichen Regionen erfahren die Energiewende nicht mehr als notwendiges nationales Projekt, sondern als zerstörerische Kraft. Der Widerstand wächst.Volker Tschischke ist gerade von einer längeren Dienstreise zurück, als die Revolution sein Wohnzimmer erreicht. Irgendetwas ist anders, hat er eben noch gedacht. Nun steht Tschischke am Fenster, sieht über den Dachgiebeln der Nachbarhäuser zwei riesige Windräder und ist einen Moment lang unsicher, ob die neu sind oder er sie bisher bloß nicht bemerkt hat.
Später fällt ihm auf, dass abends in der Küche die wuchtigen Schatten von Windradflügeln über die Wand wischen. Und nach einiger Zeit bemerkt er, dass er bei Ostwind nachts unruhig ist und kaum noch in den Schlaf findet. Auch die Nachbarn sagen, sie hätten oft Ohren- und Kopfschmerzen. Sie machen dafür den Schalldruck der Windkraftanlagen verantwortlich.
Weiterlesen in der Welt
Der Vogeltod geht unterdessen weiter. Auch hier werden die Umweltverbände nach längerer Schockstarre endlich aktiv:
Das International Institute for Applied Systems Analysis gab am 21. Juli 2016 eine Pressemiteilung heraus, in der das Abholzen von Regenwald für Palmöl-Plantagen verurteilt wird. Allerdings werden auch Lösungsvorschläge angeboten, um Nachhaltigkeit zu erreichen. Wichtigste Botschaft: Es gibt angeblich noch reichlich unbewirtschaftete potentielle Anbauflächen außerhalb der Regenwälder.
Can palm oil be sustainable?
A new study shows to where and to what extent palm oil plantations could be expanded, while avoiding further deforestation in pristine and carbon-rich tropical forests.
Land used for palm oil production could be nearly doubled without expanding into protected or high-biodiversity forests, according to a new study published in the journal Global Environmental Change. The study is the first to map land suitable for palm oil production on a global scale, while taking into account environmental and climate considerations. “There is room to expand palm oil production and to do it in a sustainable way,” says IIASA researcher Johannes Pirker, who led the study.
Palm oil production has expanded massively, from 6 million hectares in 1990 to 16 million in 2010, an area about the size of Uruguay. The oil, which is used for cooking and as a food additive, now accounts for about 30% of all vegetable oil used worldwide. Palm oil is controversial, in particular because much of this expansion came at the expense of biodiversity-rich tropical forests, which were cut to make room for new plantations. But oil palm farming has also contributed to lifting millions of people out of poverty in Indonesia and Malaysia, the top palm oil producing countries. And an important share of palm oil producers are small-holder farmers who rely on the commodity as their primary income.
With palm oil as the number one cooking oil in Asia, where populations are rising, demand for the oil is expected to continue growing, and many developing countries are looking to expand their production. Yet it was not clear how much land is available for expansion. In the new study, researchers started by creating a global map of where the conditions are right for producing palm oil, based on temperature, rainfall, slope, and soil type.
From a purely biophysical perspective, they found that nearly 1.37 billion hectares of land globally are suitable for oil palm cultivation, in Africa, Central and South America, and Asia. From this they then removed any land which is already being used for other purposes, such as farming, residences, or cities. For this, the researchers relied on the hybrid land cover maps developed at IIASA using crowdsourced data.
Finally, the researchers ruled out areas that are protected by law, as well as forests that are particularly valuable from a biodiversity or carbon storage perspective. With all of these areas removed, the resulting map includes an area of 19.3 million hectares of very suitable land which could potentially be available for future production. This is slightly more than the current extent of palm oil production, 18.1 million hectares. However, among this area, about half is more than ten hours drive to the closest city which might not allow for economically profitable oil production. The map, published online, is also available for download.
“This analysis will be a useful tool to identify area for future oil palm investments that meets some basic environmental standards. The maps are available to stakeholders who can combine them with local information to address other dimensions of sustainable development,” says IIASA researcher Aline Mosnier, who also worked on the study.Growing attention to the deforestation caused by palm oil has led many companies to begin aiming for sustainability certification in their sourcing. However, the researchers argue that consumers and companies need to go a step beyond that. Pirker says, “Moves to ban palm oil are misguided. What we need to do instead is look at the origin of the oil, who is growing it how and where. Certification is a first step in the right direction but companies committed to sustainability should look in more detail at their supply chains, and consumers can demand this of them.”
Reference
Pirker, J., Mosnier, A., Kraxner, F., Havlik, P. and Obersteiner, M. (2016) What are the limits to oil palm expansion? Global Environmental Change, 40, 73-81 doi:10.1016/j.gloenvcha.2016.06.007
Blick nach Großbritannien. Die Deutschen Wirtschaftsnachrichten machten sich am 17. Juli 2016 Sorgen, dass London aus der überteuerten Energiewende aussteigt:
Großbritannien will die globale Energiewende kippen
Die neue Premierministerin Theresa May schafft das Ministerium für Klimawandel ab. Die Zusammenlegung mit dem Energie-Ressort dürfte eine Abkehr der Briten vom Klimaschutz bedeuten. Setzt sich diese Position global durch, hat Deutschland schlechte Karten.Weiterlesen in den Deutschen Wirtschaftsnachrichten
Auch der frühere wissenschaftliche Berater der britischen Regierung, David MacKay, hält es für eine Illusion sich mittelfristig nur durch Erneuerbare Energien zu versorgen (siehe auch Artikel im Guardian vom 3. Mai 2016):
Blick nach China. Trotz Pariser Klimaabkommen hat sich die chinesische Regierung dazu entschlossen, 150 Milliarden Dollar in den kommenden 5 Jahren in neue Kohlekraftwerke zu investieren. Nicht ganz, wozu sich die Staatschefs Ende 2015 eigentlich verpflichtet hatten. Ein bewährtes Verfahren: Man sagt das eine und tun das andere. Nachzulesen bei The Daily Caller.
Der Schlüssel für eine effektive Nutzung erneuerbarer Energien liegt in der Speichertechnologie, bzw. im bisherigen Fehlen einer solchen. Clive Best hat in seinem Blog nocheinmal vorgerechnet, wieviel Speichervolumen eigentlich geschaffen werden müsste:
The average German daily electrical energy demand is 1.4 TWh during winter months but can peak to 1.6 TWh. A standard (65Ah) car battery can store 0.78 KWh of energy. Therefore to power Germany for one day without any significant wind or solar input during winter would need at least 1.8 x 10e9 (1,800,000,000) batteries!
There are currently 1 billion cars and trucks in the world. So Germany’s energy storage solution would need to requisition all of these , plus then manufacture 800 million more just to cover one day without wind in Winter.
If instead Germany decided to buy Tesla Powerwall battery packs priced at $3000, then they would only need 220 million of them for a total cost of $660 billion. However for energy security insurance they probably need about seven times that number to cover a full week for a total cost of ~ $4.6 trillion.
Realismus ist gut, Verzweifeln führt aber auch nicht weiter. Wer hat vor 100 Jahren für möglich gehalten, dass es heute Computer gibt? Das menschliche Gehirn ist leistungsfähiger als man denkt. Ein gangbarer Weg in Sachen Speichertechnologie könnte über die Umwandlung von Wind- oder Solarstrom in Flüssigtreibstoffe führen. Das Paul Scherrer Institut (PSI) stellte am 7. Juli 2016 in einer Pressemitteilung ein interessantes Konzept hierfür vor:
Sun-Petrol – how solar energy can be transformed into fuel
Finding sustainable petrol – how solar energy can be transformed into fuel
The sun is a clean and inexhaustible source of energy, with the potential to provide a sustainable answer to all future energy supply demands. There’s just one outstanding problem: the sun doesn’t always shine and its energy is hard to store. For the first time, researchers at the Paul Scherrer Institute PSI and the ETH Zurich have unveiled a chemical process that uses the sun’s thermal energy to convert carbon dioxide and water directly into high-energy fuels: a procedure developed on the basis of a new material combination of cerium oxide and rhodium. This discovery marks a significant step towards the chemical storage of solar energy. The researchers published their findings in the research journal Energy and Environmental Science.
The sun’s energy is already being harnessed in various ways: whilst photovoltaic cells convert sun light into electricity, solar thermal installations use the vast thermal energy of the sun for purposes such as heating fluids to a high temperature. Solar thermal power plants involve the large-scale implementation of this second method: using thousands of mirrors, the sun light is focused on a boiler in which steam is produced either directly or via a heat exchanger at temperatures exceeding 500 °C. Turbines then convert thermal energy into electricity.
Researchers at the Paul Scherrer Institute PSI and the ETH Zurich have collaborated to develop a ground-breaking alternative to this approach. The new procedure uses the sun’s thermal energy to convert carbon dioxide and water directly into synthetic fuel.
“This allows solar energy to be stored in the form of chemical bonds,” explains Ivo Alxneit, chemist at the PSI’s Solar Technology Laboratory. “It’s easier than storing electricity.” The new approach is based on a similar principle to that used by solar power plants.“ Alxneit and his colleagues use heat in order to trigger certain chemical processes that only take place at very high temperatures above 1000 °C. Advances in solar technology will soon enable such temperatures to be achieved using sun light..
Producing fuel with solar heat
Alxneit’s research is based on the principle of the thermo-chemical cycle, a term comprising both the cyclical process of chemical conversion and the heat energy required for it—referred to by experts as thermal energy. Ten years ago, researchers had already demonstrated the possibility of converting low-energy substances such as water and the waste product carbon dioxide into energy-rich materials such as hydrogen and carbon monoxide.
This works in the presence of certain materials such as cerium oxide, a combination of the metal cerium with oxygen. When subjected to very high temperatures above 1500 °C, cerium oxide loses some oxygen atoms. At lower temperatures, this reduced material is keen to re-acquire oxygen atoms. If water and carbon dioxide molecules are directed over such an activated surface, they release oxygen atoms (chemical symbol: O). Water (H2O) is converted into hydrogen (H2), and carbon dioxide (CO2) turns into carbon monoxide (CO), whilst the cerium re-oxidizes itself in the process, establishing the preconditions for the cerium oxide cycle to begin all over again.
The hydrogen and carbon monoxide created in this process can be used to produce fuel: specifically, gaseous or fluid hydrocarbons such as methane, petrol and diesel. Such fuels may be used directly but can also be stored in tanks or fed into the natural gas grid.
One process instead of two
Up to now, this type of fuel production required a second, separate process: the so-called Fischer-Tropsch Synthesis, developed in 1925. The European research consortium SOLAR-JET recently proposed a combination of a thermo-chemical cycle and the Fischer-Tropsch procedure.
However, as Alxneit explains: “although this basically solves the storage problem, considerable technical effort is necessary to carry out a Fischer-Tropsch Synthesis.” In addition to a solar installation, a second industrial-scale technical plant is required.
Direct production of solar fuel now possible
By developing a material that allows the direct production of fuel within one process, the new approach developed by Ivo Alxneit and his colleagues dispenses with the Fischer-Tropsch procedure and hence also with the second step. This was accomplished by adding small amounts of rhodium to the cerium oxide. Rhodium is a catalyst that enables certain chemical reactions. It has been known for some time that rhodium permits reactions with hydrogen, carbon monoxide and carbon dioxide.
“The catalyst is a pivotal research topic for the production of these solar fuels,” says Alxneit. His PhD-candidate at the PSI Fangjian Lin emphasizes: “it was a huge challenge to control the extreme conditions necessary for these chemical reactions and develop a catalyst material capable of withstanding an activation process at 1500 °C.“ During the cooling process, for example, the extremely small rhodium islands on the material surface must not be allowed to disappear or increase in size since they are essential to the anticipated catalytic process. The resulting fuels are either used or stored and the cyclical process begins again once the cerium oxide is re-activated.
Using various standard methods of structure and gas analysis, researchers working in laboratories at the PSI and the ETH in Zurich examined the cerium-rhodium compound, explored how well the reduction of the cerium oxide works and how successful methane production was. “So far, our combined process only delivers small amounts of directly usable fuel,” concludes Alxneit.. “But we have shown that our idea works and it’s taken us from the realms of science fiction to reality.”
Successful tests in high performance oven
During their experiments, researchers kept things simple by using a high performance oven at the ETH in place of solar energy. “In the test phase, the actual source of thermal energy is immaterial,” explains Matthäus Rothensteiner, PhD-candidate at the PSI and the ETH Zurich whose area of responsibility included these tests.
Jeroen van Bokhoven, head of the PSI’s Laboratory for Catalysis and Sustainable Chemistry and Professor for Heterogeneous Catalysis at the ETH Zurich adds: “These tests enabled us to gain valuable insights into the catalyst’s long-term stability. Our high performance oven allowed us to carry out 59 cycles in quick succession. Our material has comfortably survived its first endurance test.” Having shown that their procedure is feasible in principle, researchers can now devote themselves to its optimization.
