BRS Solar Technologies
BSR Solar Technologies GmbH ("BSRsolar"), a private company located near Basle in the southern part of Germany, develops solar products for global application. The company, formerly part of the Bomin Solar Group, has been in the forefront of innovative solar technology developments over the last 30 years. The creative forces behind the company, Jürgen Kleinwächter, and until 1997 his father, the late Prof. Hans Kleinwächter, are both considered European pioneers in solar technologies.
The mission of BSR Solar Technologies is twofold: develop systems powered by renewable energies (in particular by solar radiation) for deployment in sunbelt countries to help meet water and energy needs. Through technology transfer, local partners transform these systems into local products with "German engineering inside"
become a leading developer of Stirling-technology-based distributed power generation and energy saving systems for application in developed economies
It is the business policy of BSRsolar to conduct the final development phase jointly with industrial partners and to commercialize its products through a global network of local marketing partners.
In pursuit of this policy BSR Solar Technologies seeks marketing partners for developed products and development partners for products still under development.
To download a company brochure, please
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The Company
Core Technologies
Low-Temperature
Stirling
Medium-Temperature
Stirling
Heat Storage
Concentrator PV
Marketing Partners Sought
Solar Pumping Systems
Hot-Water Collector
Development Partners Sought
Brochures to Download
Contact Information
Core TechnologiesBSR Solar Technologies has a rich pipeline of proprietary technologies:
StirlingBSRsolar's Stirling technology SUNPULSETM is a technology for crankless, non-resonance, free-piston engines. BSRsolar develops engines for two temperature ranges:
Low-Temperature Stirling Enginespowered by unconcentrated solar radiation with 80°C to 130°C at the hot end.
BSRsolar's low-temperature Stirling engine is powered by unconcentrated solar radiation. The first application is the solar-thermal pumping system SUNPULSETM water.
The absorber surface of about 3 square meters converts the solar radiation into heat of about 100°C inside the engine at the hot end whereas the temperature at the cold side is kept at about 30°C. Thus, according to the Law of Carnot, the engine can ideally achieve the efficiency of 19% of which it realizes about 70%, thus achieving an efficiency of 13%.
The displacer moves with a frequency of 0.5 to 1.0 Hz; the pressure inside the engine fluctuates between ± 100 mbar exerting a force of 1,000 kg on the 1 square meter power piston.
Medium-Temperature Stirling EnginesOver the last decades mainstream Stirling development has been focusing on high-temperature (>800°C) and high-frequency (>50Hz) engines in order to achieve good efficiencies.
BSR Solar Technologies GmbH is pursuing a radically different approach with the development of medium-temperature (200°C to 500°C), low-pressure (about 10 bar) and low-frequency (0.5 to 5 Hz) Stirling engines. Due to this relatively low temperature/pressure/frequency constellation, the percentage of the ideal Carnot efficiency achieved for a given temperature difference is much higher than that realized by high-temperature Stirling engines. For temperatures of 300°C (and 30°C on the cold side) the ideal Carnot efficiency is about 48% of which 75% is realized by SUNPULSETM engines, that is 36% (see graph below). This equals the value achieved by conventional Stirling engines at a temperature of 800°C and higher.
BSRsolar's medium-temperature Stirling technology brings very favorable economics to the design and construction of Stirling engines. In conventional high-temperature Stirling engines the displacer and the piston are synchronized. To maintain a momentum of both at all times, costly crankshafts, heavy flywheels and other devices are necessary for temporary storage of mechanical energy. In addition, they need very expensive material.
With the introduction of an innovative Stirling valve the SUNPULSETM technology decouples the movement of the displacer and the power piston, thus making crankshafts or flywheels superfluous. The phase between displacer and power piston is variable and adjusts automatically to the respective pressure/frequency constellation of the total system. The engine adjusts optimally to varying energy supply levels of the system and changes in mechanical performance can be accommodated for short intervals.
Heat StorageBSRsolar's Heat Storage Technology SOLARSTORAGETM is a thermo-chemical storage technology for medium-temperature (200°C to 500°C) heat. The thermo-chemical storage system is specially suited for round-the clock operation of solar-powered systems and to overcome longer periods without sunshine as they occur in the Northern Hemisphere. For sunbelt countries, BSR Solar Technologies has developed a system utilizing plant oil as the heat-storage medium.
BSR Solar Technologies GmbH, jointly with the Max-Planck-Institut in Mülheim/Ruhr, has developed the thermo-chemical heat storage technology, SOLARSTORAGETM. The storage medium is metal hydride, which has a high heat-storage capacity. For instance, 1 kg of magnesium-hydride has the capacity to store 0.8 kWh of medium-temperature heat reversibly and practically without loss.
Storage of heat energy
The heat energy to be stored is supplied to the "high-temperature unit", a closed high-pressure system filled with magnesium hydride (MgH2). When the system is heated up, the hydrogen is set free and is transferred to the "low-temperature unit", a closed system to store the hydrogen.
The chemical reaction taking place is:
MgH2 —> Mg + H2 -75kJ/mol (dissociation reaction)
Release of stored heat:
When the hydrogen is transferred back to the high-temperature unit nearly the same amount of energy stored during the dissociation reaction cycle is released.
Mg + H2 —> MgH2 +75kJ/mol (exothermal recombination reaction)
Concentrator PVBSRsolar's Concentrator PV Technology, COOLPHOTONTM, enable hybrid thermal/photovoltaic systems with concentrator PV modules cooled frontside through a selective filter, extracting the infrared radiation for thermal energy generation and preventing the PV cells from becoming too hot and thus less efficient.
BSRsolar's concentrator PV-technology COOLPHOTONTM significantly increases the economics of photovoltaic (PV) systems through front-side cooling of concentrator PV cells (concentration factor of up to 20) via a liquid filter.
The function of the filter is twofold: (1) to absorb the infrared radiation, i.e., photons supplying heat and (2) to let the UV and visible radiation pass through to the PV cells below. The filter consists of a fluid absorbing, storing and carrying thermal energy for other use.
1. concentrator PV cells
2. transparent filter system
3. pump for cooling circuit
4. heat exchanger
5. thermal energy
Hot-Water CollectorBSRsolar's Collector Technology, SOLARBOXTM, is a pressure-less, isothermal system with built-in water storage. Equipped with a special fluorpolymer foil, UV-radiation penetrates and disinfects, freeing the water from bacteria and viruses.
BSR Solar Technologies has developed the solar hot-water system SOLARBOXTM that is simple in design and is highly economical. The innovation of SOLARBOXTM is based on the employment of a special fluorpolymer foil. This allows the penetration of the sun's full radiation spectrum (incl. UV-radiation) thus heating and simultaneously disinfecting the water.
The SOLARBOXTM is an integrated hot-water collector/storage system. When heated up by solar radiation the SOLARBOXTM functions as an isothermal system, i.e., the increasing volume of hot water is kept within a temperature range of 3°C.
The main advantages of the SOLARBOXTM technology as compared to conventional collectors are as follows:
Better utilization of solar energy: In the SOLARBOXTM technology the black absorber surface is located at the bottom of the box; thus the solar photons first pass through the water. As a result 90% of the photonic energy is converted into thermal energy to heat the water. With conventional collectors the absorber is located on the water surface: solar photons first hit the absorber and an important portion of the heat produced remains in the absorber instead of heating the water.
Heating and storage in one unit: The SOLARBOXTM system is both, collector and storage, storing water of up to 250 liters per square meter. With the conventional version the collector and storage tank are separated and connected by pipe.
Natural UV disinfection: Miraflow®, the special foil that covers the SOLARBOXTM, allows UV radiation to penetrate and disinfect, freeing the water from bacteria and viruses. Conventional collectors do not have this capability.
Superior economics: With the SOLARBOXTM technology the cost of manufacturing a solar-powered hot water system can be reduced to 60% of that for conventional collectors.
Lightweight Precision Solar OpticsBSR Solar Technologies has developed an innovative "pneumatic solar concentrator" employing a thin reflective foil combined with a drum and an air-under-pressure system shaping the reflective foil into a highly effective concentrating optic, as well as Fresnel lenses and mirrors and other special optics.
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FLAT PLATE SOLAR/STIRLING POWER SYSTEMS - SUN PULSE (TM)There are several advantages to using flat plate technology of which the primary one is that of greatly reduced cost. The major drawback is that the engine works with a much lower temperature differential, hence lower efficiency and power output, however this is not a problem when applying solar technology in countries having limited financial resources.
One of the pioneers of low temperature solar machines is Bomin Solar Research of Germany who have been developing engines, designed to operate below 100°C, since 1989. One of their latest concepts is the SUNPULSE engine which consists of three mechanical components: the solar collector box, the oscillator control system and the mechanical power system.
Unconcentrated solar radiation enters the solar box (3) through a transparent cover (2) and is absorbed by the black top (4) of the regenerator absorber (5) and converted into heat. The regenerator consists of material pervious to air and is moved up and down within the solar box.
Edited by fabrizio3 - 4/2/2010, 04:02
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