Ara

Connection with the grid from house to house Distribution line Main distribution line Fig. 10.7 Transmission routings (see 10-2 ) Hybrid connection (combination of both options) Hybrid connection (combination of both options) Because of the moisture within the soil, corrosion resistance is the major requirement to be met by the distribution system. Also, moistening of the insulation needs to be prevented with regard to limiting heat losses. Primarily, plastic jacket pipes equipped with steel...

Conventional energy provision systems

The addressed renewable sources of energy and the corresponding technologies can be applied for the provision of heat and or power, by substituting conversion technologies based of fossil fuel energy. It is thus sensible to compare the assessed options of using renewable sources of energy with the corresponding fossil fuel-based options which they are to substitute. For this purpose, standard conventional energy provision technologies based on fossil fuel energy, used for comparison, are...

Definitions

The translucence of walls is often described by the terms opaque, transparent, and translucent, as well as by solar aperture surface. The opaque building envelope is not permeated by light and includes, for instance, brick walls, or a roof covered with tiles. Transparent and translucent parts (e.g. windows) of the building are permeable by solar radiation. In general, the word transparent means clear, whereas translucent parts of the building can not be seen through. In terms of solar...

Economic analysis

Three grid-connected wind energy converters operated on the mainland (i.e. onshore installation) of different capacities (1.5, 2.5 and 5.0 MW) are considered as representative. The converters are installed within a medium size wind park (consisting of about 10 converters). The rotors are provided with three blades made of glass fibre-reinforced plastic, whereas towers are made of steel. For converter manufacturing, series production is assumed. Converters are mounted on regular good load...

Economic and environmental analysis

Compared to hydro-geothermal heat generation systems, deep well heat supply systems are almost location-independent as such deep well systems are characterised by a closed circuit system (i.e. closed system). Such systems consist of a well and the pertaining completion, a heat exchanger which usually includes a heat pump and a fossil fuel-fired peak load plant. Depending on the consumer structure, an additional heat distribution network may be required. The following paragraphs contain an...

Energy balance of the earth

The energy flows of the earth are fed from various sources described below. Solar energy has a share of more than 99.9 of all the energy converted on earth. The solar radiation incident on the earth is weakened within the atmosphere and partially converted into other energy forms (e.g. wind, hydro power). Therefore the structure and the main attributes of the earth's atmosphere will also be described in more detail, followed by balancing the global energy flows. Solar energy. The sun is the...

Energy conversion chain losses and characteristic power curve

Grid-connected photovoltaic power generation is aimed at the supply of grid-compatible alternating current (AC), which is provided from radiated solar energy at several energy conversion levels illustrated in Fig. 6.29. As shown in the diagram, solar radiation energy (i.e. diffuse and direct radiation), and thus the photons energy content, is first converted into potential energy of the electrodes of the semi-conductor material they are now able to move freely within...

Fx Wa

Grid-connected or off-grid 20 K 50 kW 40,000 m2 6,000 m2 A variety of types of plastic sheet, as well as glass, were selected in order to establish which was the best - and in the long term, most cost effective - material. It was found that glass is able to withstand even severe storms over many years without damage and proved to be self-cleaning occasional rain showers were sufficient. Completion of the construction phase in 1982 was followed by an experimental phase, the purpose of which was...

Geothermal power generation

Geothermal power production has a relatively long history. Just 38 years after the invention of the electric power generator by Werner von Siemens and 22 years after the start of the first power station by Thomas A. Edison in New York in 1882, geothermal power production was invented by Prince P. G. Conti in Lardarello, Italy in 1904. Geothermal power production in Tuscany has continued since then and amounted to 128 MW of installed electrical power in 1942 and to about 790 MW in 2003. In 1958,...

Heat pump

A heat pump - like any other technical system - consists of various system elements. In the following, they are primarily explained further for electrical compression heat pumps, as they have the highest market share (e.g. 9-1 , 9-2 , 9-3 , 9-12 ). It can be differentiated by the heat exchanger utilised in the evaporator and the condenser, the compressor, the expansion valve, the lubricant as well as the working medium (refrigerant). Heat exchangers. Heat exchangers are devices that transfer...

Info

On some days, the diurnal course of the wind velocity can deviate significantly from the mean diurnal course given in the yearly average due to changing local weather conditions. However, in the course of one year, stationary weather conditions generally prevail. The diurnal course exemplarily described for the site of Norderney Germany is equal to the diurnal course at a thermal stratification during robust weather conditions, with a strong mixing of the air layer close to the ground during...

LS

Lubricant 382, 410, 412 lubricant loss 379 luminous reflectance 345 luminous spectrum 125 magma chamber 470 magma deposit 96 magmatic body 470 magnetic field 293, 314, 315 magnetic induction gauge 73 magnetic valve 419 majority carrier 232 malfunction 194, 293, 347, 462 (MWD) 440 mechanical brake 313 mechanical deterioration 258, 327 mechanical efficiency 326 mechanical energy 2 mechanical energy 323, 351, 370 mechanical failure 348, 382 mechanical loss 325 mechanical power 295 mechanical pump...

Photo effect

The term photo effect refers to the energy transfer from photons (i.e. quantum of electromagnetic radiation) to electrons contained inside material. Photon energy is thereby converted into potential and kinetic energy of electrons. The electron absorbs the entire quantum energy of the photon defined as the product of Planck's quantum and the photon frequency. External and internal photo effect is distinguished. External photo effect. If electromagnetic radiation hits the surface of a solid body...

Principles

Plants consist of the stem, leaves and roots. The latter anchors the plant in the ground and enables it to withdraw water and nutrients from the soil. The stem carries the leaves, supplies the plant with water and nutrients from the root, and carries the organic substances generated in the leaves to the root. The leaves absorb the sunlight required for photosynthesis. They enable the gas exchange of carbon dioxide (CO2), oxygen (O2) and steam (H2O) for...

Solar Thermal Power Plants

The term solar thermal power plant comprises power plants which first convert solar radiation into heat. The resulting thermal energy is subsequently transformed into mechanical energy by a thermal engine, and then converted into electricity. For thermodynamic reasons high temperatures are required to achieve the utmost efficiency. Such high temperatures are reached by increasing the energy flux density of the solar radiation incident on a collector. In this respect, we refer to concentrated...

Supply characteristics

In order to be able to measure short and long-wave radiation fluxes through the atmosphere, a number of different measuring instruments are available. Relative and absolute instruments are generally differentiated 2-3 , 2-10 . If radiation energy has to be measured in absolute terms, the incident solar energy has to be converted into a measurable parameter first. Most of these radiation measurement instruments thus absorb the radiation energy on a blackened surface which...

V

Velocity of the air inside a chimney tube (tower) Maximum velocity of the air inside a chimney tube (tower) Velocity of a wind-blown surface (S) vwi, Wind velocity at reference point 1 vwi, 2 Wind velocity at reference point 2 vwi, a Wind velocity at a defined site (a) vwi, h Wind velocity at a defined altitude (h) vWii Wind velocity at reference point i vwi,North Wind velocity, northern hemisphere vwi, ref Wind velocity at a reference altitude (href) vwiRot Wind velocity within the rotor level...

Nsa

Wind power exploitation aims at extracting the maximum share of wind power. Due to physical restrictions wind masses flowing through rotor level cannot be entirely slowed down, as a complete slowdown would clog the rotor and impede power extraction. On the other hand, wind velocity must be decreased if power is to be extracted from flowing air masses. Consequently, there must exist a certain ratio between the speed long before and far behind the rotor that corresponds to the maximum power...

Gridindependent applications

The majority of all individual wind turbines and wind parks are connected to the power grid. However, there is also a multitude of grid-independent and winddiesel systems designed for small power grids which are outlined throughout the following sections. Wind-battery systems. In most cases, grid-independent wind battery systems are small capacity wind turbines which, coupled with a battery and a battery charge regulator, supply one or several power consumers. The nominal capacities of the...

System components

Free Energy Collector Components

In the following, the individual components of such a power plant are presented and discussed. Collector. The hot air required for the operation of a solar updraft tower power plant is created by a simple air collector. The latter consists of a horizontal translucent glass or plastic roof located approximately 2 to 6 m above ground (Fig. 5.27). The translucent roof is permeable by solar radiation, but impermeable by the long-wave heat radiation emitted by the collector bottom, which is heated...

Further system components

Solar generators as well as battery storage systems principally deliver direct voltage or direct current (DC). Many small appliances (such as watches and calculators) are designed for DC supply. However, most appliances require alter nating current (AC) of 230 V and a frequency of 50 Hz (in some cases 120 V at 60 Hz, as in the US, for instance). Even, for stand-alone photovoltaic systems without grid-connection, frequently inverters are used to convert direct current (DC) into the...

Overall systems

Free Energy From Air

Heat source systems (Chapter 9.2.1 and 9.2.2) and heat pumps (Chapter 9.2.3) are integrated into overall systems that enable the utilisation of ambient air or shallow geothermal heat as end and useful energy respectively. Therefore firstly typical system configurations for characteristic applications are described. Afterwards system aspects of such overall systems will be discussed. System configurations. In the following, a heating system with exhaust air heat recovery and exhaust-air to...

Idealised wind energy converter

The considerations outlined throughout this section with regard to assessing the theoretical total capacity extractable by means of wind energy converters (such as a rotor) are based on the following ideal conditions and assumptions - frictionless, stationary wind flow, - constant, shear-free wind flow (i.e. wind speed is the same at every point of the energy extracting surface (e.g. circular rotor surface SRot) and flows into shaft direction), - rotation-free flow (i.e. no wind deviation into...

So

Fig. 6.25 Schematic of a photovoltaic system for supply of a direct current load or direct current consumer application (PV photovoltaic generator, DC direct current) Fig. 6.25 Schematic of a photovoltaic system for supply of a direct current load or direct current consumer application (PV photovoltaic generator, DC direct current) Photovoltaic systems, applied, for instance, for household or small consumer supply, generally consist of a solar generator, a charge controller and an energy...

System elements

Currently and in the near future, almost exclusively grid-connected horizontal three-blade rotors and, to a very limited extent, also two-blade rotors hold a predominant market position. The principle plant design is illustrated in Fig. 7.11. A grid-connected wind power station thus consists of rotor blades, rotor hub, gearbox, if applicable, generator, tower, foundation and grid connection. Depending on the respective wind energy converter type further components may be added. Fig. 7.11 also...

Ff

Reduction factor of the g-value due to the window frame Axial component of the lifting force Tangential component of the lifting force Reduction factor of the g-value due to fixed shading Fwi, slow Force given by the wind energy converter slowing down the wind flow Fw ,weC Overall wind force affecting the wind energy converter g Energy transmittance factor g-value gdiff n Diffuse energy transmittance factor diffuse g-value Gabs Radiation flux density of the absorber Gap Radiation flux density...

Utilisation of Ambient Air and Shallow Geothermal Energy

Diagram Geothermal Energy

A typical characteristic of ambient air and near-surface heat it is the very low temperature level. The heat is mainly generated by solar radiation Chapter 2 . Only a small part of the energy in the soil i.e. shallow geothermal energy is not produced by the sun, but by the geothermal energy flow caused by the heat potential available within the earth i.e. deep geothermal energy . The share of geothermal energy normally increases proportionally with an increasing depth underneath the surface of...

Power control

Wind energy converters require appropriate control mechanisms to limit power extraction at higher wind speeds Fig. 7.17 . Power controls prevent mechanical deterioration of the rotor and are also required due to the capacity thermal limitation of the generator i.e. matching the installed electric capacity . On principle, power and speed controls need to be distinguished 7-3 . If the number of revolutions must be kept constant, or almost constant, power has to be controlled accordingly. It must...

Wind parks

Wind energy converters may be installed individually in exposed positions, for instance at the hilltops of low mountain ranges with free airflow, in rows e.g. converters positioned along a dike or in groups e.g. positioned in lines, one behind the other . For the latter two variants certain minimum distances, depending on the respective site conditions, need to be observed, to prevent reciprocal shut-down of the converters and to ensure relatively undisturbed wind conditions...

Drag and lift principles

Lift And Circumferential Force Airfoils

There are two different principles available for technically exploiting moving airflow by rotating wind energy converters, which can also be combined under certain conditions. Energy can be extracted from flowing air masses either by the lift or drag method. In the following both principles are explained. Lift principle. According to the lift principle, wind is deviated to generate peripheral force inside the rotor. For high-speed propeller-type converters, in most cases rotor blades are...

Photosynthetically fixed energy

Biomass in the broader sense is all phytomass and zoomass. An estimated total of 1.84 1012 t of dry mass exists on the continents. The major part of phytomass or plant mass is generated by autotrophic organisms that can generate the energy they need to survive by exploiting solar energy through the process of photosynthesis. Heterotrophic organisms, though, of which zoo mass primarily consists of, need to consume organic substances to produce energy. Biomass can be divided into primary and...

Kem

Solar Updraft Tower Circuit Diagram

Fig. 10.18 Simplified schematic diagram of a geothermal power production facility operating according to the ORC Organic Rankine Cycle Within the temperature range of fluids extracted from geothermal wells, usually hydrocarbons such as n-pentane, isobutane are applied as working fluids. In the past, also fluorocarbons such as C5F12 have been used. Furthermore, the application of mixtures of hydrocarbons is under consideration, as they promise to enhance efficiencies due to their smooth...

Wasserkraftanlage Plannung Bau Und Betrieb Giesecke J. Mosonye E.

Renewable Energies Lessons Institute for Environmental Technology and Energy Economics, Hamburg University of Technology, Summer Term 2006 and Winter Term 2006 07 1-2 Hulpke, H. u. a. Hrsg. R mpp Umwelt Lexikon Georg Thieme, Stuttgart, New York, Germany, USA, 2000, 2. Auflage 1-3 BP Hrsg. BP Statistical Review of World Energy 2005 BP, London, UK, June 2006 www.bp.com 1-4 Kaltschmitt, M. Hartmann, H. Hrsg. Energie aus Biomasse Springer, Berlin, Heidelberg, Germany, 2001 1-5...

Solar updraft tower power plants

Updraft Tower Plant

For a solar updraft tower power plant the three components of glass roof collector, chimney and turbine are combined. The use of this combination for power generation was already described more than 70 years ago 5-26 . Fig. 5.24 Function principle of a solar updraft tower power plant Fig. 5.24 Function principle of a solar updraft tower power plant The principle, on which a solar updraft tower power plant is based, is shown in Fig. 5.24. The incident direct and diffuse solar radiation warms the...