The energy balance of the biomass

The true potential of the only suitable substitute for orgol – part ii

Biomass, yes! "Because she is regenerative and inexhaustible" – in any case, the explanation on a website of the german biomass lobby. However, it remains critical that the biomass may be regenerative, but it is unneedable, it is only conditionally. If you z.B. Get out which plant has the best energy balance and then growing this worldwide, this monoculture would be a catastrophe for the soil as well as the plant and wildlife. With the biomass want to be done correctly. How do you do that?

Under energy balance, the energy is understood in the biomass, which is made out of her out of her the energy that has been inserted into it: the diesel for tractors and transport, the dungem means, possibly the energy for the conversion into a gas or a liquid, etc. But before we work with it, first a word for the applicability of the term above.

The energy balance of the biomass

The biomass is often criticized that their energy balance is so bad. In comparison to other renewable energies, that is certainly correct:

A wind turbine produces a multiple of energy necessary for their production, construction and disposal. Even the photovoltaic creates loose more than 5 times as much energy as she needed. In the ethanol, however, it is scarce; in the ethanol from corn is even claimed to be the energy balance in some cases even negative. Source: own treasures according to different studies.

It is also often asserted, a coal-fired power plant or a nuclear power plant was even better: during a wind turbine in a favorable location energetically already in less than a year and the pv is paid in a few years, creating a coal or a nuclear power plant invested in the invested energy in less than a month. While this is right, as long as letting out that a coal or nuclear power plant devours huge amounts of non-renewable resources. The increasingly scarce resource here is nowhere in the calculation.

Take the example of a coal power plant with a typical efficiency of around 35%, d.H. About two-thirds of the energy contained in the coal escapes unused as a departure. So you always put 3 times as much energy in a conventional coal-fired power plant, as in the end meant out. When considering this fact in the so-called energy balance, there is one "-3" there. Then it is clearly clear that we plug in more energy into such power plants as they generate when the coal is scarce.

The errol is already so far. According to a report of november 2003, you will win 17 times more energy today through the demands of the errol, when you invest. 100 years ago, the eroi (energy return on investment) was 100 years ago. The tendency is strongly sinking.

Unlike the renewable energies: here is the energy used to coarse part of solar energy, d.H. According to human mabs unchecked. We do not expect the sun if we build more pv systems. And the wind blast no less heavily over germany, since then 14.000 facilities here.

The more we change to renewable raw materials (nawaro), the better our "macro": we still had products, although we make less raw materials to mull. The term nawaro refers to the biomass as a whole, not only for energetic purposes. Makes you z.B. Electricity poles made of wood instead of concrete or steel, the co2 emissions are reduced in excess:

The biomass binds namely co2 and other elements from the atmosphere. While these are always released in rotting or combustion, but only the same amount as bound. The biomass is therefore co2-neutral. You have to keep that in mind if of the "emissions" the biomass is the speech. In comparison: we put in combustion of fossil fuels 150.000 times as much co2 free, as in this way, is naturally bound, because the amount of coal, gas, and ol, which we consume or more, has estimated about 150.000 years accumulated.

A comparison between the energy balance of renewable energies and non-renewable is therefore completely miscarriage. If the resources of one day have become scarce, we will no longer operate these conventional power plants. But the coarse of the power plant park is operated with renewable energies, the gross is the basis for further growth without fossil energy. On this meadow you reduce the "mullberg" in the broadest sense: valuable resources like oil are spared, while less waste (co2, etc.).

A first step in this direction is also done when bio-substances are mixed with fossil fabrics. Aligned as well as biofuels in fossil fuels today, you can betray coal power plants with wood and straw. The oko institute appreciates in her study "bioenergy: offspring for germany" from 2004, that up to 10% biomass could be mixed without coarse technical effort. Only demanding and similar infrastructure elements for the biomass had to be reinstalled.

In england are already the first onset of power plant operators who also want to burn olive and palm nuclei with beside the coal. Olive residues (the so-called "olive cake") anyway other fruit nuts and residues are already being combined in some power plants of sudeuropas. And not only in the conventional coal-fired power plants, but also in the new igcc systems (coal as a bridge to the renewable future) one can use biomass.

Other power plants are now set to biomass, for example the straw-fired 36mw system in ely / england. The straw has a nearly neutral energy balance. Is it worthwhile to burn straw, or would not be better to import fruit rates from sudenuropa? Or even better: could not avoid transport losses by burning the fruit trials right in sudenuropa?

The energy balance of the biomass

Which plant has the best energy balance?

It’s true: it’s not worth it, "straw" (cereals) to build as an energy plant. But you do not even do that – you do not have to, as the straw is available as waste product from agriculture in coarse quantities. Printed differently: you can do the excess straw – there are more straw in many regions than you need for animal feed – either undergrow in the field or level to combine energy production. The latter is economically more meaningful, the former leads valuable substances into the ground, so that this is not leached. But if you burn the biomass, you can still use the ashes as a dungem means.

So you can see that the pure calculation of the energy balance of a plant does not say everything. In addition, the existing figures for energy balance are not necessarily reliable, because the transport routes, for example, are not calculable. No wonder that reliable estimates are hard to find, because you can not determine all parameters.

Nevertheless, the comparison of the scattered energy balances of different energy crops is worthwhile, because in addition to the energy density, these are a key parameter for the decision whether the cultivation of a certain variety of biomass and their transport was meaningful about a certain distance. Under the title fairbiotrade, the iea has launched the task 40 in order to investigate exactly when the trade of which variety biomass is worthwhile, and how it can be supported.

As you have seen above, the wooden ethanol has a better energy balance than the ethanol from corn. Why do you build up corn as an energy plant?? The question can be expanded, because the highest legislation bring very specific, fast-growing wood types such as poplars and pastures. Even better, however, palms and reedgraser (miscanthus). Known is the now retired television journalist and author franz alt as advocate of thesis that the cheavage could cover our entire energy supply. He estimates the yield to 30 tonnes of dry matter per hectare / year, 14.000 liters heating perforated per ha / year. Even more conservative falls the association of energy experts dieter seifried and walter witzel, which is the possible yield to a maximum of just under 12.000 liters quantifiers, with mean values under 10.000. But at least: it would be twice as much as in wedding and poplars.

The energy balance of the biomass

Why do not you build cheaven-swed plantations instead of fast-growing walder? According to a us study, the ethanol from corn has an energy balance of 121%, but from reeds, but 3.430%. In germany one sets less on ethanol (as a gasoline additive), but on rapsol (diesel). But why builds rape when the yield of reeds in theory is so much better?

Well, on the one hand there are already critics of miscanthus. In recent decades, the practical disadvantages of the miscanthus have turned out. Like dr. Hermann hansen, bioenergermaner at the specialized agency renewable raw materials, explained on request by telepolis. First, the miscanthus is a multiannual plant in contrast to rapeseed, d.H. There are a few years before being harvested at all, and only years after that you get the most highest. (dr. Hansen, however, spoke of a high degree of around 20 tons of the year, 33% less than franz alt.) at the rape, on the other hand, you get every year – with natural fluctuations – the highest yield.

A miscanthus plantation is in this regard like a plantation of poplars, where you also plan and have a long breath. Unlike walls and rape fields, however, the harvest is a problem at miscanthus, because the plant is harvested in spring when the floor is rather wet. If the machines fall too deeply into the ground, tear the root plant. This soil compression is generally a potential problem in agriculture, even at rapeseed, so dr. Hansen, because when it rains in autumn at the harvest, the machines leave deep traces in the fields. This soil compression at the harvest, however, is less bad for one-year plants, as the soil then the soil is usually reconciled anyway.

Similar obstacles are determined at the olen: for example, the palmol should have a multi-better energy balance than the rape. Unfortunately, palm trees in germany can grow badly, and the transport from sadden latitudes is relativized the balance. In addition, one gives his energy independence from the hand, if you import everything. The rapeseed can be grown in germany on stored flats, and if you use the whole plant – not only the seeds – then the energy balance is considered again.

The conclusion of the biomass: it must be varied, d.H. You have to grow different plants so that the biomass remains sustainable. Monocultures are to be avoided. You have to look how to use unused biomass – from biowaste to unused wood residues and straw – energetically.

Spectacular breakdown?

Three newer developments should not remain unhessed, but they are not rated here because they are just as speculative as spectacular.

The energy balance of the biomass

The first development concerns algae in salt pages created in the waste. These algae were according to estimates of nrl on a flat descent in the magnitude of 38,000 km2 – less than a tenth of the total cotton flax in the us – so much biodiesel producing that the us did not even need to be fueled (heating is not included to). If this method proves to be effective and does not bring environmental pollution (z.B. Solid soil in the desertion through evaporation), this was extended by the area usable for the biomass for rough custodia areas. The researchers are confident that all environmental problems can be solved.

About the second development, a lot in the us press under the reiber inscription ol was reported from all (better the turkey in the tank than the pigeon on the roof). Already for a long time you can win gas from biomass and biowaste, but this is about accelerating the process of natural development of the erosol – you make from waste biodiesel in a few hours. After the american discover magazine reported on the procedure in 2003, the interest was roughly, but love the construction of the first coarse plant, and the magazine reported in the summer of 2004 only over the delay due to nature.

A pilot plant, which makes 7 tons of bottlenecks to ol, love gross expectations, and the pressing spokeswoman julie gelfand of renewable energy resources said against zutuber telepolis that the new facility that processes more than 200 tonnes per day, now (december 2004) 80% is busy and ol manufactures at a price of $ 15 per barrel.

The third development refers to all-plants. We remember: the rapeseed us only uses the seeds. However, the entire energy balance is impaired if you areangel, blatter, etc. Also energetically recycled. Here, among other things, the company choren from germany is interesting. She has developed a technique that can not only process allsuit, but also mixed plants, d.H. You do not need monocultures (like the rape), but you can easily mahen the meadow.

Energy sectane or energy source? Macro

If we manage to sustainably expand the biomass, we will probably need to change our whole lifestyle. To illustrate this, we have to take a look at our eating habits.

The authors of "the limits of growth" gather that today more energy is put into fish farming, as it comes out of the fish in the end. Similarly, agriculture: we pump so much dungem means that our fields produce less energy than we invest. A swiss study has found that around 20% less yield in bioan construction, but it starts 50% energy. It is not just about the energy itself, but about all resources that are scarce. Example: the island of naurau – 2001 became known by the escape, which australia presented there after they were not left as an immigrant into the country – is a moon landscape; the dismantling of the phosphate there makes the island uninhabitable.

Another viewing angle offers the us author richard manning. He describes in the ol that we eat, like the americans eat tons of sugar and egg. They have diabetes and overweight. The agriculture in the us thus devours much dungem means, chemicals, and energy so that the americans become ill. In germany, the balance falls slightly better.

What manning says: from the energy balance it does not only make sense to do without meat, but also to change wild. These animals live by plants that are not very useful for people – like the fish in the sea. The energy balance falls in animals and fishing only negatively if you breed them.

In addition, we do not invest so much cereals in the animal spray, there will be a lot of land free for energy crops. We were healthy by the cleaner environment and the for people more suitable food.