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Energy sources of the hydrogen economy (NOT YET FULLY EDITED) Hydrogen is no energy source. Hydrogen must be produced from other forms of energy. Hydrogen is therefore a secondary energy carrier, like electricity. When producing electricity from carbon containing energy carriers, high losses must be accepted for thermodynamic reasons. In comparison, when producing hydrogen an almost complete conversion of the primary energy into hydrogen is possible (see H2-Production). As the hydrogen economy is a future project, this page mainly examines the potential renewable energy sources. The potential of renewable energy sources is almost infinite. Even with wind, solar cells and biomass, could each produce enough energy, so that all atomic and fossil fuel energy carriers could be replaced. However the option of hydrogen principally from biomass is the most cost effective. Realistically a mix of 70% biomass and 30% renewable electricity may be assumed. In the long term, the differences in cost between hydrogen from biomass and hydrogen from electricity are negligible, because many renewable electricity stations are already written off and the sun is known not to send a bill.
The potential of biomass worldwide The fossil energy carriers will become so expensive by 2050 that only a few countries will be able to afford them. For this reason the search is on for a cost effective alternative. One alternative would be the installation of a sustainable hydrogen economy. A worldwide completion of a hydrogen economy is hardly realistic before 2050. The biomass capabilities must therefore only be available by 2050. Fortunately the harvest yield for food is growing faster than world population. There are constantly more areas available for energy production. That is why there will be enough to eat and sufficient energy for our comfort. Following an extensive Dutch study [1], the certain global technical capability of biomass considering ecological and economical aspects is around 300 EJ. As a possibility, more than 1500 EJ is specified. It is assumed here that the identified capability must be suitable for the technologies which are used today. That is the cultivation of fuels (oils), sugar and wheat (ethanol) and fermentable plants. As biomass of every type can be used very efficiently in a hydrogen economy, and the decentralised use of hydrogen more efficient, the capacity is much larger in a hydrogen economy. The study [1] proves for example that for fuels at a capacity of 150 EJ prices of < 1 ct/kWh are archievable. If energy plants with high yield mass per hectare were cultivated in the same fields instead of high value produce (oil plants, grain, sugar beet), one would harvest three times as much energy. That would then be twice as much as would be needed for a wasteful energy lifestyle. An important point is really sustainable forestry returning minerals following gasification. Then the wood yields particularly in the nutrient poor soils of the tropics and subtropics could be multiplied. With this, energy provision from wood would be possible, without touching food provision at all (see below). This aspect was not researched in the study [1]. The demand for biomass in Germany was calculated to be 2.5 EJ for the same energy mix (see efficiency). If it is assumed that a world population of 8 billion people wanted to live with the same energy comfort, then 250 EJ of biomass would be required (see below). |
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Demand and capacity 2050 worldwide |
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Capacity in Germany for 2030 Germany and the EU practice a highly subsidised agricultural policy. In doing so, the surpluses are exported at giveaway prices to countries which either do not want to or cannot afford to subsidise farming. That principally concerns the third world. The prices there for imported food (grain, vegetables and meat) cannot be undercut. People are therefore starved on fertile uncultivated fields. In this way the EU is exporting hunger into the third world. In light of this practice of subsidies, the biomass capacity with respect to its economic efficiency in the EU is traditionally only considered to be the part left over in the current situation. The capacity in farming is then according to the definition almost zero. The governmental codeword which researchers are instructed not to mention in their studies, is world food security, which is the export of hunger via subsidised food exports. It does not get more cynical. To obtain an idea of the possible energetically usable biomass capacity, a plausibility evaluation of biomass capacity should be determined, given a 100% food self sufficiency without export subsidies. In 1980, the then European economic community had reached a 100% self-sufficiency for food. At that time, the wheat harvest in Germany was around 4.5 t/ha, around the average for the European economic community. In 2010 this yield could be increased to 8.7 t/ha in Germany and will rise to 11.8 t/ha by 2030. For all other types of grain and vegetables, the yield increase was even higher. In addition the milk and meat production has become ever more efficient by breeding and computer controlled feeding of animals. The milk production of a cow from the EU average in 1980 was 3500 kg/a. The proportion of a kilo of meat per kilo of feed is increasing with a similar speed as harvest yields. For example if 50 years ago 5 kg of feed were required for 1 kg poultry meat, it is now only 1.6 kg. At this juncture it should be noted that the meat consumption in Germany is decreased since 1980. Through the grain yields alone, only one third of the farming area would be needed by 2030. As grain is mostly used for animal feed, the required farming area would decrease to one quarter, considering the efficiency gains in milk and meat production - at 100% self sufficiency for man and animals. In other words, there would be around 13 million hectares from 17 million available for energy production. Independent of this plausibility evaluation a large european study [6] came to similar results. Here the surplus farming area is shown to be around 11 million hectares. However, it should be noted here that in this Ethanol study only areas suitable for the cultivation of sugar beet and grain are considered, so only for more demanding plants. The breeding of maize has reached yields of around 30 t/ha today. In 2005 it was only around 15 t/ha. After 2030 >40 t/ha will become possible. If plants were bred according to their biomass yield rather than their biogas yield, even higher yields would be possible. An additional point is the use of two harvests per year. With that not only are yields increased, but ecological farming with respect to quality of the environment can be far surpassed. An unusually high biological diversity is possible. This use of a two culture system was developed by the University of Kassel / Witzenhausen. Energy plants are not always maize - wild flowers can have a similarly high yield. An additional option would be to achieve another harvest after the grain harvest with a catch crop. The root system of this catch crop would also secure the humus balance without having to plough in straw every third year. The cultivation of catch crops was the rule until the 1960s. The catch crop (grass, clover, alfalfa) was used as animal feed. In the process of globalisation, farmers have now found out that meat can be produced more cheaply with soybean meal than with domestic grass or grain. The surplus grain is now exported in addition. That is why Germany has risen to be the fourth largest agricultural exporting country in the world [7]. An energy volume of 1300 PJ can be extracted from German forests if 50% of the waste wood (branches and tree tops) remain in the forest [2]. It is assumed here that industrial wood is used energetically at the end of its use cycle (cascaded use). The forest therefore has a lower specific yield (4.5 t/ha) than trees on a field (10-20 t/ha) because taking away the wood also takes the nutrients which can only be replaced by dust from the air. The regulation that 50% of the waste wood must remain in the forest is neither beneficial to the forest nor its fauna if usual mechanised harvesting is employed, because this wood remains on forest tracks. The romantic idea of individual tree harvesting can no longer be paid for. Through the total nutrient withdrawal forest soil is extremely low in nutrients. Really sustainable forestry as described by Hans Carl von Carlowitz (1713) means giving the forest back the minerals taken away in the form of ash. The wood yield would then double in the longer term. By introducing really sustainable forestry the energy provision for Germany could be achieved 100% from the forest. From ash fertilization there are no additional costs worth mentioning, because the ash can be added to the lime which anyway needs to be brought out.
Capacities in Germany:
For 100% sustainable energy provision for Germany around 2500 PJ biomass would be required, if 1000 PJ of renewable electricity were integrated. |
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Capacity in Germany The diversity of energy crops
As one can see, the energy for electricity, heat and mobility can be secured from German biomass alone. A change of lifestyle and saving of energy above the economic extent is not necessary. In contrast to the commonly held view, this environmental protection concept does not cost anything. In fact money is produced, as the energy prices will sink by between 60-80%. Even the changeover to a hydrogen economy is much cheaper than todays concept of muddling along. The climate protection negotiations are then unnecessary.
Europe For Europe as a whole, the difference between capacity and demand is even larger than shown here for Germany. That is mainly because the population density is much smaller. No biomass needs to travel from rich countries to poor countries. Biomass will be transported in the form of bio hydrogen. The pipelines are already available and sufficiently dimensioned. |
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Literature: [1] Dornburg, Faaij, VeweiJ; Biomass Assessment Assessment of global biomass potentials and their links to food, water, biodiversity, energy demand and economy; Report 500102012; Der Report ist abrufbar unter: www.mnp.nl (2] DBFZ Report Nr. 4 (2011); Identifizierung strategischer Hemmnisse und Entwicklung von Lösungsansätzen zu Reduzierung der Nutzungskonkurrenzen bei weiteren Ausbau der Biomassenutzung; Seite 109-110 [3] DBFZ; Endbericht FZK 03KB021 (2012); Basisinformationen für die nachhaltige Nutzung von landwirtschaftlichen Reststoffen zur Bioenergiebereitstellung; Seite 7 [4] Hochschule Bremen und Justus-Liebig-Universität Gießen; Bestandsaufnahme zum biologischen Reststoffpotenzial der deutschen Lebensmittel und Biotechnik-Industrie (2013); Seite 105 [5] A. Wagner; Möglichkeiten der Kaskadennutzung von biogenen Abfällen; Bundesverband Sekundärrohstoffe und Entsorgung; Februar 2013 Messe Bremen [6] Thrän et al; Sustainable Strategy for Biomass Use in the European Context; Institut für Energetik und Umwelt (IE), Leipzig 2006 [7] Innovation Bioökonomie; Gutachten des BioÖkonomieRats 2010; Seite 17 |
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updated: 05.07.2014 |
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