Energy crop
A power plant is a plant that is grown specifically for energy use. Bioenergy is usually thermally, ie by combustion of solid, liquid or gaseous plant products ( biogenic fuel) won.
Definition and delimitation
As the power plant agricultural crops are referred to that are grown with the main goal of power generation into deferred to plants for food production, food plants and industrial plants. Wild -growing plants, which are used for energy purposes, eg as firewood, are not counted as energy crops. Forest plants that are grown on agricultural land for energy production ( for example, in short-rotation plantations) are occasionally recorded with. In some cases the whole plant of energy crops is only spoken in a energetic use.
The crucial factor is the use of the plant. Thus, for example corn are cultivated as sweet corn for human consumption as well as forage maize (corn silage) for animal feed or as energy maize for biogas production. The varieties and methods of cultivation of energy crops used differ partially used by the in food and feed, depending on the type of production.
Groups of plants and use
Numerous plant species are suitable for the production of energy. These include both traditional crops of agriculture, are bred for the optimized partly for the use of energy types (such as canola, corn), as well as crops that were previously not or hardly used for agricultural purposes, in terms of energy use, however, be interesting (eg, miscanthus, Inconsistent Silphie, Sida hermaphrodita ). So far, the production is concentrated on already widespread arable crops. The breeding of new varieties and the use of new crop species are only at the beginning. The table below lists some in Central Europe as energy crops cultivated plant species and groups. Energy crops with significant acreage or a lot of potential in other regions are, inter alia, soybean, oil palm, jatropha and sugar cane.
Energy crops are used with the aim of generating heat and electrical energy as well as biofuels. Here comes a variety of usage paths are used, especially the fermentation and biogas production in biogas plants (use as fermentation substrate ), combustion (use as biofuel ) and various other forms of full or partial conversion of the biomass (among pyrolysis, generating synthetic biofuels (BtL ) ). Energy sources are either the plant substrate even after crushing (eg biogenic solid fuels such as firewood, pellets), pressing / extraction or further processing (eg biogenic liquid fuels such as vegetable oil fuel, bioethanol, biodiesel, BTL) or by gasification of biomass derived energy gases (eg biogenic fuel gases such as biogas, syngas, hydrogen).
Scale cultivation and development
In Germany energy crops on 2.28 million hectares cultivated (as of 2011). This corresponds to 19 % of the total arable land in Germany. Of this amount, over a million acres to the cultivation of rapeseed for biodiesel and vegetable oil fuel, to more than 500,000 ha to grow plants for biogas production, and more than 250,000 ha are used for culture of sugar and starch crops for bioethanol. The cultivation of energy crops has increased dramatically in recent years - In 1998, the total area under cultivation for renewable resources in total (including attachments to material use ) nor less than 500,000 ha Current estimates puts the Agency for Renewable Resources ( FNR) the area under cultivation for renewable resources in Germany in 2012 to around 2.5 million hectares. The predominant portion of which increases with 2.1 million hectares a cultivation of energy crops. The main energy crops are still rapeseed for biofuels, and corn, other grains and grasses for biogas plants. The smaller portion of the acreage is used for renewable raw materials that are used for chemical- technical applications in industry.
Promotion
The cultivation of energy crops has been under the common agricultural policy of the European Union with direct payments ( so-called energy crop premium ) provided financial support. Such support for a maximum of 45 € / ha will be abolished in 2010. As part of the set-aside requirement by 2007 farmers were allowed to grow on a portion of their arable land no food or feed, and we were given a set-aside premium. The cultivation of energy crops on this land, however, was admitted. An energy crop premium to farmers for crops grown on land not set aside. The abolition of compulsory set aside and the energy crop premium loses the direct promotion of energy crop cultivation in importance.
Environmental effects
Through the use of energy crops energy carriers can be provided environmentally friendly. The reduction of carbon dioxide emissions (CO2) in order to reduce the greenhouse effect is an important factor. The climate impact of the cultivation and use of energy crops is controversial. In addition to the CO2 savings through the use of renewable raw materials carbon footprints of agriculture to the climate-relevant emissions of nitrous oxide N2O consider that arises especially in stickstoffgedüngten arable crops. Cultivation and land use can also have a major influence on the climate impact of energy crop cultivation: For clearing of rain forests, the cultivation of peatlands or upheaval of grassland for cultivation of energy plants large amounts of greenhouse gases are released.
The European Union has adopted the valid from June 2009 Renewable Energy Directive ( EC). With it, among other sustainability criteria for the promotion of biofuels and their recognition will be introduced to the EU biofuel targets. The implementation of these sustainability criteria into German law was carried out with the Biomass Electricity Sustainability Ordinance ( BioSt sustainability ordinance, effective from August 2009) and the Biofuel Sustainability Ordinance ( Biofuels Sustainability Ordinance, effective from September 2009) ..
A goal of research on energy crops is to improve the energy yield per acreage by use of the whole plant and process optimization. In addition, methods for expanding the usable area to be examined, such as breeding of saltwater algae in desert areas or cultivation of jatropha oil -sufficient.
The areas that are necessary for the cultivation of energy crops, but could also be used for other economically and ecologically meaningful purposes (eg for material use of renewable raw materials, extensive agriculture ). In addition, they are no longer of food production are available ( competition for space ). Given the population growth ethical issues are discussed in this context, particularly the use of foods such as cereals (eg corn combustion ) is criticized ( competing uses ).
The cultivation of energy crops is often operated as a high-intensity agriculture, including in relation to fertilizer and pesticide use, which can lead to environmental damage. The cultivation of plants from other regions of origin as energy crops involves risks, eg dissemination of neophytes.