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...

Environmental analysis

For the systems utilising ambient air and shallow geothermal energy analysed so far (Table 9.7) a number of selective environmental parameters are discussed below occurring during construction, normal operation, in the case of an accident and at the end of operation. Construction. The environmental effects caused by installing a heat pump system for ambient heat utilisation are mainly due to the use of water as a heat source and, for ground probes, sinking the boreholes. Potential environmental...

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

In order to achieve a higher solar fractional saving of around 70 , a non-selectively coated collector area of approximately 15 to 18 m2 or a selectively coated collector area of 10 to 12 m2 would be required in the described case. The storage volume would have to be around 600 l. During the summer, however, collector standstills can occur on a regular basis. DHW system with closed natural circulation. Most solar thermal DHW plants in Southern Europe are built with closed natural circulation...

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...

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...

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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...

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...

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...

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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...