Category Renewable Energy
by Christian Matt | Matthias Schuler
This example of a German therapy center including residential accommodation shows how an intelligent concept is capable of cleverly joining ecology and economy. Furthermore, the combined biofuel and cogeneration unit of the neighboring farmer makes even the heating largely autonomous.
he architectural office of Michel, Wolf and Partners (Stuttgart, Germany) has developed a complex of buildings in cooperation with Transsolar Energietechnik GmbH (Stuttgart) featuring an exceptional energy concept. It emerged from an old mansion in the Bergheim district to the northwest of Stuttgart. The plan was to renovate this villa so that it would accommodate a therapeutic institution for a group of just under 40 handicapped people...Read More
In the construction and the energy management of the new government buildings along the River Spree in Berlin, future – oriented, environmentally responsible and exemplary energy concepts were required . The energy-supply system of the Berlin parliament buildings therefore contains, along with components for combined heat-cooling-power production, two aquifer storage reservoirs (Figure 2). The heat storage reservoir increases the contribution of the combined heat and power plant to the overall energy supply, even when the system is power-directed. The cooling reservoir permits the use of the low winter temperatures for air conditioning in the summer months.
The storage region is a sandstone stratum at a depth of 285 to 315 m which contains salty water (brine)...Read More
OWC is the abbreviation for Oscillating Water Column and describes a design which makes use of the wave motion in rising and falling water columns. Figure 5a shows how a typical OWC functions. It consists of a chamber with two openings. One of these is on the side towards the incoming waves and lies beneath the water level. The water can enter the chamber through this opening, driven by the wave energy. The second opening allows the pressure to equalize with the surrounding air. The water column in the chamber moves up and down at the wave frequency, and thus “breathes“ air in and out through the second opening. This “breath” drives an air turbine...Read More
by Andrea Vezzini
Electric cars indeed operate emission-free when the power for charging their batteries comes from renewable sources (Figure 1). Even when their power is generated from fossil sources, they show a good C02 balance, since
they utilize the electrical energy very efficiently. Our measurements at the Bern University of Applied Sciences in Biel, Switzerland on an all-electric city vehicle, the Mitshu – bishi i MiEV, which has been on the roads in Europe since 2010, clearly demonstrate this. They showed a reduction of about 60 % in CO2 emissions compared to a standard model with an internal-combustion engine, provided that the electric power was supplied entirely from a modern gas and steam combined-cycle plant.
The automobile industry has in the me...Read More
By 2050, according to our scenario, transmission lines with a capacity of 2.5 to 5.0 GW each must be able to transport around 700 TWh of solar energy per year from 20 to 40 different locations in the Middle East and North Africa to the major centers of consumption in Europe (Table 9), thus supplying ca. 15 % of the European power requirements. The cost of these imports is based on low production costs of ca. 0.05 12000-ct./kWh and a high flexibility for base-load, balancing power and peak-load operation (see below). Since our present AC grids would have overly high transmission losses at such high power levels and long transmission distances, it will be necessary to employ HVDC transmission lines...Read More
by Michael Vollmer | Klaus-Peter Mollmann
In this field, the word “infrared” is often replaced by “thermal”, so that one usually speaks of thermal cameras and thermal images.
This basically positive development however creates some problems, in particular since the false-color images must be interpreted correctly. There are many traps lurking here, and we demonstrate some of them using examples. For this reason, several businesses and also the camera manufacturers offer training and certification courses on the fundamentals and applications of thermography . To be sure, such courses cost as much as the less expensive cameras, so that some “services” dispense with the course and nevertheless offer thermographic analyses.
This is where the problem begins, as measurements ...Read More
For the storage of thermal energy in a field with downhole heat exchangers (DHE), the underground strata also serve as the storage medium. Here, the reservoir is tapped by a number of boreholes of 20 to 100 m depth, usually symmetrically arrayed, and these are outfitted with probes.
A geothermal field with DHE is an underground closed system in which there is no hydrological connection between the storage medium (earth) and the heat transport medium. The heat transport for charging and discharging takes place through the walls of the probes. The charging and discharging thermal power is thus proportional to the
surface area of the probes and to the temperature difference between the thermal transport medium and the storage medium...Read More
Between 1978 and 1986, in an international experiment initiated by Japan, an OWC system was tested for the first time on a large scale: The ship Kamai’ carried out three series of tests in the Japan Sea in which turbines with up to a megawatt of power output were installed. Only in 1998 was the idea of a floating OWC again taken up in Japan. The new Japanese prototype ’Mighty Whale’ however has a power output of only 110 kW (Figure 2). An Irish group is currently testing a reduced-scale floating construction at sea.
It has taken a similarly long time for the first continuation of coastal projects to be pursued, with an OWC of relatively high power output...Read More