August 5th, 2016
The new SunOyster lens paves way for receiver with 75% total energy efficiency in co-generation of power and heat
Hamburg, 5 August 2016. SunOyster Systems GmbH (SOS), the Hamburg-based manufacturer of the concentrating solar technology SunOyster for the co-generation of power and heat, reaches a technical
milestone in their R&D project of developing its concentrator cell receiver. “We are very happy that thanks to this new lens – the “SunOyster Crystal” – we are getting much closer to our target
of supplying in sunny areas the cheapest form of solar energy wherever heat or cold is needed” says General Manager Dr. Carsten Corino.
The receiver is the heart of the SunOyster. After the parabolic mirrors have concentrated the direct sun light 30 to 40 times onto the receiver, the receiver concentrates it a second time and transforms it into electricity and heat. In order to reach this target, a glass lens in the receiver is concentrating the sun light 16 times onto the highly efficient concentrator cells. The secondary concentration is needed to make full use of the precious concentrator cells which were originally developed for space applications. These multi-junction cells consist of three serially connected layers of semiconductor material, and each of them is converting a different part of the solar spectrum into electricity. At the same time, heat is generated and collected by a fluid circulating through the receiver. The development of the SunOyster receiver, for which patents are pending in Europe, US, India and China, is supported by the German Foundation of the Environment.
The new SunOyster Crystal allows not only an electric efficiency of 30%. A very important property of the lens is also its high tolerance regarding positioning and tracking errors.
“Although we are able to track in the millimeter range, it is of course much easier over the life-time of 20 years to reach the receiver position with a tolerance of roughly a centimeter, and also cheaper” explains SOS’ head of workshop Stephan Ulrich.
The new lens reaches a geometrical concentration of 530x. Taking into consideration the optical efficiency of approx. 75%, the optical concentration is a good 400x. The design of the lens was supported by Dr. Ralf Leutz, founder of Leutz Optics and Illumination. The prototype of the lens with a shape of a mountain crystal was cut and polished in the Bavarian Forest – where natural mountain crystals (also named “German diamond” by mineralogists) are found. Bigger numbers of the lens will be pressed from molten glass to reach low unit costs. One SunOyster receiver will contain more than 60 SunOyster Crystals and a corresponding number of cell assemblies. The two receivers of one SunOyster shall have a power output of almost 5 kW electrical plus 7.5 kW thermal.
SOS is presently selecting worldwide demonstration projects for the pre-series of its solar CHP technology, e.g. in the fields of process heat, solar cooling or swimming pools. The company has orders for a dozen machines in particular from Chile, Egypt and India, and further machines are under negotiation. SunOyster Systems is moreover organizing a Series B financing round.
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Brussels/ Hamburg, 20 June 2016. SunOyster Systems GmbH (SOS), the Hamburg-based manufacturer of the CPVT system SunOyster, is among the few German companies to pass the evaluation phase of the new SME instrument of the European Commission.
The EU instrument offers a 70 per cent funding for small and medium enterprises – in particular YICs (Young Innovative Companies) like SOS – to realize their project in the topic “Stimulating the innovation potential of SMEs for a low carbon and efficient energy system”. While during the first phase the company shall prepare a detailed feasibility study, the second phase offers up to 2.5 M€ grants to implement the business plan. The success rate of German SMEs in this program is well below 10%, for start-ups like SOS even lower.
Increasing demand for air conditioning with worldwide more than 100 million units of compression air conditioners sold alone in 2014 has led to dramatic growth in electricity demand in many countries, to increasing electricity costs and brownouts. An obvious possibility to counter this trend is to use the same energy for cooling that contributes to the cooling demand – solar energy.
The objective of the SOcool Project is to use a concentrating photovoltaic/thermal (CPVT) system – the SunOyster – combined with chillers to provide the most cost-efficient solar energy on the market in form of electricity, heat and cold. This shall help achieving the 2K target of the Paris Convention while enhancing the living standard in rather hot climates, also as an adaptation strategy to global warming.
The SunOyster is a concentrating solar technology which can generate at the same time electricity and heat with a high total energy efficiency of 75%. From serial production, this will result in very low electricity and heat costs. While the electricity can easily be converted into other forms of energy and can be fed into the grid, the heat is more difficult to convert and has to be used locally. A technically, micro-economically and macro-economically very good form of using the heat in hot climates is converting it into cold for the cooling of buildings.
The biggest markets will be Southern Europe (Spain, Southern France, Italy, Greece and Turkey), Northern and Southern Africa, the Gulf region, India, South-East Asia, parts of China, Southern USA, parts of Middle and South America.
The preparation of the project application was accompanied by Dr. Harald Eifert and his Hamburg team of EuRA Consult AG. The feasibility study shall draw on the experience of French solar cooling expert Dr. Daniel Mugnier who is also heading the IEA Solar Heating and Cooling Task 53 on innovative solar cooling systems. Several SunOyster customers have already ordered small solar cooling systems or are in the process of doing so.
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