Sunday, June 21, 2009

A bio-energy village

A bio-energy village

A bio-energy village is a regional orientated concept for the use of renewable energy sources in rural areas. The system uses biomass from local agriculture and forestry in a Biogas powerplant in order to supply the energy demand of a village preferably complete, as electricity and district heating.
These villages tend to be self-powered and independent from external grids; despite being connected to overland grids for feeding surplus energy. The term bio-energy village describes only the energy dependency on fresh biologic material, whereas an ecovillage includes much more differentiated networks.

Energy production

Liquid manure, grass, silage and other raw materials from agriculture are fermented in a biological gas facility. The biogas produced fuels a combined heat and power plant (CHP). The heat is distributed over a district heating system, while power is fed into a local electricity grid. In winter additional heat requirements can be supplied by an additional heating plant, in which wood chips or straw are burned.

Existing projects


The first bio-energy village in Germany is Jühnde in the district of Göttingen. A project of the Interdisciplinary Centre For Sustainable Development (IZNE) at the University of Göttingen, and completed in January 2006, the project supplies the heat requirement of the village, and produces twice as much electricity as is used. It has been estimated that the participating households save €750 per year in energy costs.


In Mauenheim, Baden-Württemberg, a bio-energy village has been developed in Immendingen in the district of Tuttlingen, with approximately 400 inhabitants and 148 buildings. The biogas facility and wood chip heating system are supplemented by a solar energy system. The project started operation in 2006. It has been calculated that about 1900 tonnes of CO2 per year will be saved.

Sunday, June 14, 2009

Eco village: Definition


In 1991, Robert Gilman set out a definition of an ecovillage that was to become a standard.

Gilman defined an ecovillage as a:

  • human-scale
  • full-featured settlement
  • in which human activities are harmlessly integrated into the natural world
  • in a way that is supportive of healthy human development, and
  • can be successfully continued into the indefinite future.
Characteristics of ecovillages

The principles on which ecovillages rely can be applied to urban and rural settings, as well as to developing and developed countries. Advocates seek a sustainable lifestyle (for example, of voluntary simplicity) for inhabitants with a minimum of trade outside the local area, or ecoregion. Many advocates also seek independence from existing infrastructures, although others, particularly in more urban settings, pursue more integration with existing infrastructure. Rural ecovillages are usually based on organic farming, permaculture and other approaches which promote ecosystem function and biodiversity. Ecovillages, whether urban or rural, tend to integrate community and ecological values within a principle-based approach to sustainability, such as permaculture design.
An ecovillage usually relies on:
  • "Green" infrastructural capital;
  • autonomous building or clustered housing, to minimize ecological footprint;
  • renewable energy;
  • permaculture;
The goal of most ecovillages is to be a sustainable habitat providing for most of its needs on site. However self-sufficiency is not always a goal or desired outcome, specifically since self-sufficiency can conflict with goals to be a change agent for the wider culture and infrastructure. Its organization also usually depends upon some instructional capital or moral codes - a minimal civics sometimes characterized as eco-anarchism:
  • local purchasing so as to support the local economy;
  • local food production and distribution;
  • moral purchasing to avoid objectionable consumption;
  • consensus decision-making for governance;
  • a choice to respect diversity.

The term ecovillage should not be confused with micronation, a strictly legal, not infrastructural, concept.

Sunday, June 7, 2009



Ecovillages are intended to be socially, economically and ecologically sustainable intentional communities. Some aim for a population of 50-150 individuals because this size is considered to be the maximum social network according to findings from sociology and anthropology.Larger ecovillages of up to 2,000 individuals exist as networks of smaller subcommunities to create an ecovillage model that allows for social networks within a broader foundation of support. Certain ecovillages have grown by the nearby addition of others, not necessarily members, settling on the periphery of the ecovillage and effectively participating in the ecovillage community.

Ecovillage members are united by shared ecological, social-economic and cultural-spiritual values. An ecovillage is often composed of people who have chosen an alternative to centralized electrical, water, and sewage systems. Many see the breakdown of traditional forms of community, wasteful consumerist lifestyles, the destruction of natural habitat, urban sprawl, factory farming, and over-reliance on fossil fuels, as trends that must be changed to avert ecological disaster. They see small-scale communities with minimal ecological impact as an alternative. However, such communities often cooperate with peer villages in networks of their own. This model of collective action is similar to that of Ten Thousand Villages, which supports the fair trade of goods worldwide.

Saturday, May 30, 2009

Solar variation

Solar variation

An alternative hypothesis is that recent warming may be the result of variations in solar activity.Stott and colleagues have suggested that climate models overestimate the relative effect of greenhouse gases compared to solar forcing; they also suggest that the cooling effects of volcanic dust and sulfate aerosols have been underestimated.They nevertheless conclude that even with an enhanced climate sensitivity to solar forcing, most of the warming since the mid-20th century is likely attributable to the increases in greenhouse gases. Another paper suggests that the Sun may have contributed about 45–50 percent of the increase in the average global surface temperature over the period 1900–2000, and about 25–35 percent between 1980 and 2000.In 2006, Peter Foukal and colleagues found no net increase of solar brightness over the last 1,000 years. Solar cycles led to a small increase of 0.07 percent in brightness over the last 30 years. This effect is too small to contribute significantly to global warming.The general view is that the combined effect of the two main sources of natural climate forcing, solar variation and changes in volcanic activity, probably had a warming effect from pre-industrial times to 1950 but a cooling effect since.

An increase in solar activity should warm the stratosphere, whereas an increase in greenhouse gases should produce cooling there.The observed trend since at least 1960 has been a cooling of the lower stratosphere.Reduction of stratospheric ozone also has a cooling influence, but substantial ozone depletion did not occur until the late 1970s.

Svensmark and colleagues have proposed another hypothesis related to solar activity, which is that magnetic activity of the sun deflects cosmic rays that may influence the generation of cloud condensation nuclei and thereby affect the climate.Another paper found no relation between global warming and solar radiation since 1985, whether through variations in solar output or variations in cosmic rays.Henrik Svensmark and Eigil Friis-Christensen, the main proponents of cloud seeding by galactic cosmic rays, disputed this criticism of their hypothesis.A 2007 paper found that in the last 20 years there has been no significant link between changes in cosmic rays coming to Earth and cloudiness and temperature.