Solar Thermal Power Generation-the Centre of Attention
Clean energy that can generate power continuously around-the-clock
Solar thermal power generation systems use mirrors to collect sunlight and produce steam by solar heat to drive turbines for generating power. This system generates power by rotating turbines like thermal and nuclear power plants,and therefore,is suitable for large-scale power generation. For its ability to generate power around-the-clock by use of stored heat,as well as high energy conversion efficiency,solar thermal power generation is now attracting increasing attention as the most promising next-generation system.
Unlike conventional power generation systems that are dependent on oil and other depleting resources,solar thermal power generation uses clean energy and thus is free from pollution. Today,construction of solar thermal power plants is underway in many parts of Europe and the U.S. In this light,a rapid increase in the share of this system in the power generation market is anticipated after 2020.
Konica Minolta is currently engaged in development of this future-oriented energy in Abu Dhabi in the United Arab Emirates,in cooperation with Abu Dhabi's governmental agency (MASDAR-ADFEC),Cosmo Oil Co.,Ltd.,the Tokyo Institute of Technology,and Mitsui Engineering & Shipbuilding Co.,Ltd.
Note: Figures are estimate and forecast
Source: Deutsches Zentrum fur Luft-und Raumfahrt e.V
Innovative solar thermal power generation systems that employ the beam-down process
For this project,the"beam-down"solar power collection process is employed. In this process,the sunlight is first reflected by mirrors on the ground and redirected by a central reflector installed above the ground. Then,the solar heat is finally captured for storage. The mirrors on the ground are called"heliostat mirrors",which track the sun and reflect the sunlight onto a central reflector attached to the tower. The central reflector redirects the sunlight to the receiving unit on the ground where the solar heat is stored.
The effectiveness in collecting sunlight and the greater ease of handling solar heat storage materials will eventually make this process advantageous over other more conventional processes.
Development of the central reflector,the core of this new solar thermal power generation system,is undertaken by Konica Minolta Opto,Inc.
Effective Solar Thermal Power Generation Made Possible by Konica Minolta's State-of-the-Art Technology: the Central Reflector
Pursuit of higher reflectance
The central reflector to which the solar heat is directed by the heliostat mirrors on the ground receives energy greater than 30 times the energy of sunlight. Commonly used metal mirrors absorb light due to insufficient reflectance,which results in the rise of surface temperatures to more than 200°C. Furthermore,such mirrors can be subjected to pressure from strong winds of more than 20 mph. Accordingly,the beam-down process requires,among other things,development of a new mirror with higher reflectance and resistance to wind pressure.
Accomplishing this highly challenging task was the mission imposed on Konica Minolta.
High reflectance enables full exploitation of optical energy
Drawing on its expertise in dielectric multilayer films,which was accumulated through years of efforts in pursuing higher-level lens technology,Konica Minolta succeeded in developing a central reflector with 98% or higher reflectance,allowing for the full use of the optical energy as heat.
Thus,high reflectance is achieved in a wide range of wavelengths,from ultraviolet to infrared,preventing the temperature rise of the central reflector. This technology is based on Konica Minolta's leading-edge,thin film technology,such as anti-reflection coatings for camera lenses,and demonstrates excellent environment resistance,such as corrosion resistance.
Introduction to the core technologies