Birgit Gobereit

Face-Down Solid Particle Receiver Using Recirculation

Solar thermal energy generation needs receiver technologies which can drive highly efficient turbines and decouple the collection of energy from its use by an economic storage technology. High-temperature solid particle receivers for solar tower systems with particle storage are one option. Important issues regarding high-temperature particle receivers are minimization of convective losses, no particle loss due to susceptibility to wind and high efficiency also in part load operation. A design approach facing these challenges is the face-down receiver using recirculation of particles. A screening performance analysis studying different re-circulation patterns is presented. Using smart recirculation schemes, high receiver efficiencies can be main-tained also at part load operation (100%-load ~90%; 50%-load ~86%; 20%-load ~67%). In terms of total annual solar-to-electric efficiencies the face-down geometry yields excellent 24%, although implicating a surround heliostat field. From the analyses, it can be concluded that solid particle receivers using smart recirculation patterns are a viable receiver option for storage and high-temperature high-efficient turbine processes.

Cost Analysis of different Operation strategies for falling particle receivers

The potential for highly efficient and cost competitive solar energy collection at high temperatures drives the actual research and development activities for particle tower systems. One promising concept for particle receivers is the falling particle receiver. This paper is related to a particle receiver, in which falling ceramic particles form a particle curtain, which absorbs the concentrated solar radiation. Complex operation strategies will result in higher receiver costs, for both investment and operation. The objective of this paper is to assess the influence of the simultaneous variation of receiver costs and efficiency characteristics on levelized cost of heat (LCOH) and on levelized cost of electricity (LCOE).Applying cost assumptions for the particle receiver and the particle transport system, the LCOE are estimated and compared for each considered concept. The power level of the compared concepts is 125 MWel output at design point. The sensitivity of the results on the specific cost assumptions is analyzed. No detailed evaluation is done for the thermal storage, but comparable storage utilization and costs are assumed for all cases.Copyright