1. 3 rd European Energy Conference – 2013, Budapest George Papageorgiou, PhD European University Cyprus Athanasios Maimaris, PhD (cand) Cyprus College University of Cyprus Savvas HadjiXenofontos, MEng High Efficiency Renewable Energy Ltd Petros Ioannou, PhD, University of Southern California

2.  Sustainable Development and Solar Energy  The Suggested Approach  The Heliotrope Prototype  A Model of Heat Collector with a Multi- Cylinder Stirling Engine  The HelioTrope prototype showing significant gains in Torque  Conclusions and Future Work 2

3.  Real development cannot be accomplished by degrading, eliminating or contaminating natural resources such as minerals, forests, arable land, air or water.  Economic and social development must be accomplished sustainably, that is, in a way that conserves the earth’s resources for future generations and minimizes the risk of destruction.  The fact is that energy is ample around us and is unlimited and indestructible.  Energy simply changing forms and is just a matter of good management practice as how to use it efficiently and effectively. 3

4.  Solar Energy represents a viable alternative to fossil fuels as it is the cleanest and safest form of Energy and exists in vast quantities everywhere around us.  The problem of utilizing the opportunity that solar energy provides is that we tend to stick to the old ways of the past, which unfortunately lead to an unsustainable growth with disastrous consequences.  The call here is to find innovative ways of transforming and using solar energy so it can directly compete with fossil fuels. 4

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6.  The Heliotrope prototype includes a 60cm aluminium parabolic dish with a small Stirling engine in the centre. ◦ The dish is motorized in two axes in order to increase agility and maximise the incident radiation. 6

7. 7 Stirling Engine (hot end – piston) Control Board GPS - motor control

8. 8 Stirling Engine (cold end crankshaft) Azimuth motor Elevation motor

9.  In preliminary tests carried out, the hot end temperature of the Stirling engine reached 315 degrees Celsius and the cold end 45 degrees, giving a maximum theoretical efficiency of 46%  This was achieved mainly due to ◦ The first main component of the HelioTrope prototype: the concentrator dish which is shown in design form with its mirrors ◦ The second main component of the HelioTrope prototype: the Sun Tracker system - An implementation of an efficient algorithm (SPA by NREL) was carried out where the concentrator dish tracks the sun movement in order to receive the highest possible energy at the time of day and time of the year 9

10.  At the focus of the concentrating dish we have the heat collector where the Innovative Stirling Engine resides. In our design of the Stirling Engine, conversion of linear motion to circular is carried out with our patented technology, which results in significant increase of efficiency. The innovative design of this new type of Stirling engine is multi-cylinder without a crank shaft thus greatly reducing friction as well as decreasing the wear out of mechanical parts. 10

11. 11 The significant gains in efficiency are shown by the tangential Torque of our design as compared to the crankshaft torque at all displacement levels. Further, special ceramic materials are used for the cylinder design for insulating the hot and cold compartments of the engine. This maintains a significant difference in temperature, which increases the efficiency of the Carnot cycle

12.  Economic and social development must be accomplished sustainably, and the solar energy alternative provides a great opportunity in this direction.  Through our proposed approach, which is manifested in the HelioTrope prototype we suggest the integration of various solar power production components into a system that efficiently captures and converts solar energy into usable electricity.  Specifically through the Heliotrope Prototype we use ◦ An optimized manufacturing method for producing mirrors for the concentrator dish, which will ensure a fast and efficient process. ◦ An Innovative Stirling Engine Design especially developed for Solar Energy transfer to electricity, which greatly improve the system efficiency and effectiveness. ◦ A design for the implementation of a patent to convert linear motion into circular for electricity production, which gives a significant increase in efficiency and reduce maintenance costs. 12

13. 3 rd European Energy Conference – 2013, Budapest George Papageorgiou, PhD European University Cyprus Athanasios Maimaris, PhD (cand) Cyprus College University of Cyprus Savvas HadjiXenofontos, MEng High Efficiency Renewable Energy Ltd Petros Ioannou, PhD, University of Southern California