Energy , renewable

Before the industrial revolution, renewable energy was the only energy source used, and biomass as wood is still an important power source in underdeveloped and developing countries. 

At present, biomass is the most important renewable energy with a share of about 10% of the global energy consumption, but most biomass is stUl traditional biomass (Table 5.1.1), and the overuse of firewood leads to deforestation and desertification. Traditional biomass should, therefore, not be regard as renewable and its share will, hopefully, fall if developing countries shift to modem forms of energy. 

Apart from biomass, hydroelectricity is the only other renewable energy that currently makes a considerable contribution to the world energy production (Tables 5.1.1 and 5.1.2). The long-term maximum technical potential is believed to be 10-times the current hydropower production, but environmental concerns also have to be considered. 

At present, wind power is the most rapidly growing form of alternative electricity generation. Thousands of wind turbines with a total capacity of about 60 MW are in operation, of which Europe accounts for 70% (31% Germany, 17% Spain, 5% Denmark), the USA for 16%, and India for 8% (2005). However, the share of wind energy in terms of global consumption of less than 0.1% is still marginal (Table 5.1.1). 

On a global level, geothermal energy also plays a minor role (0.4% of the world s total primary energy consumption. Table 5.1.1), but there are local variations, for example, in Iceland with 17% of total electricity production and in New Zealand (7%). Moreover, geothermal energy is also used non-electrically by heat pumps, but there are no reliable data on this usage. 

biofuels (including liquid biofuel, solid biomass, and biogas). 

Biofuel is any fuel with an 80% minimum content by volume of materials derived from living organisms harvested within the 10 years preceding its manufacture. A drawback with biomass is that it needs to be grown, collected, dried, fermented, and burned. All these steps require resources and an infrastructure. The carbon in biofuels was recently extracted from atmospheric carbon dioxide by the growing plants, so burning it does not result in a net increase of carbon dioxide in the earth s atmosphere. Hence it is considered a renewable source. 

Certain types of biomass have attracted research and industrial attention, since they are available in very large quantities and have low market value. They are algae, bagasse from sugarcane, dried distiller s grain, firewood, hemp, jatropha, maize (corn), manure, meat and bone meal, peat, rice hulls, silage, stover, and whey. 

A number of liquid forms of biomass can be used as a fuel  

Liquid biofuel is usually bioalcohol such as ethanol and biodiesel and virgin vegetable oils. E85 is a fuel composed of 85% ethanol and 15% gasoline that is currently being sold to consumers in the United States. The European Union plans to add 5% bioethanol to Europe s petrol by 2010. 

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J. H. Perry and C. P. Perry, Methanol Bridge to a Renewable Energy Future University Press of American, Lanham, Md., 1990. 

A projection of biomass energy consumption in the United States for the years 2000, 2010, 2020, and 2030 is shown in Table 6 by end use sector (12). This analysis is based on a National Premiums Scenario which assumes that specific market incentives are appHed to aU. new renewable energy technology deployment. The scenario depends on the enactment of federal legislation equivalent to a fossil fuel consumption tax. Any incentives over and above those in place (ca 1992) for use of renewable energy will have a significant impact on biomass energy consumption. 

Projections of market penetrations and contributions to primary consumption of energy from biomass are subject to much criticism and contain significant errors. However, even though these projections may be incorrect, they are necessary to assess the future role and impact of renewable energy resources, and to help in deciding whether a potential renewable energy resource should be developed. 

S. Feim, Institutional Investment in Renewable Energy Technologies, Renewable Energy Institute, Washington, D.C., Feb. 1987, 50 pp. 

D. L. Klass, ed., A. Directory of U.S. Renewable Energy Technology Vendors, Biomass, Photovoltaics, Solar Thermal, Wind, Biomass Energy Research Association, Washington, D.C., 1990, for U.S. Agency for International Development, 74 pp. 

First Biomass Conference of the Americas Energy, Environment, Agriculture, andindustry, NREL/CP-200-5768, DE930/0050, Proceedings Vols. I—III, National Renewable Energy Laboratory, Golden, Colo., 1993, 1942 pp. 

The Potentialfor Renewable Energy Nn Interlaboratoy White Paper, Office of PoHcy Planning and Analysis, U.S. Dept, of Energy, SERI/TP-260-3674, Washington, D.C., 1990, p. C-2. 

The discovery of chemical N2 fixation under ambient conditions is more compatible with a simple, complementary, low temperature and low pressure system, possibly operated electrochemically and driven by a renewable energy resource (qv), such as solar, wind, or water power, or other off-peak electrical power, located near or in irrigation streams. Such systems might produce and apply ammonia continuously, eg, directly in the rice paddy, or store it as an increasingly concentrated ammoniacal solution for later appHcation. In fact, the Birkeland-Eyde process of N2 oxidation in an electric arc has been... 

N. N. Lichtin, in PuralPower Etilities and the KoleofPhotovoltaics, South Pacific Institute for Renewable Energy, Tahiti, 1991, p. 119. 

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