高倍率的聚光型太陽能模組設計雖然解決了三五族多接面晶片成本昂貴的問題，卻因為使用高倍率的透鏡而造成晶片發熱及表面照度不均勻的問題，進而造成晶片效率降低。本研究利用適當簡化的熱傳導及光電轉換效率理論模型，以解析的方法探討晶片表面不均勻照度對其轉換效率的影響，並且提出一個可以提供晶片表面均勻照度的聚光鏡設計，以解決高倍率聚光型太陽能模組目前所面臨的技術瓶頸。
有關前述理論模型，我們將模組背板視作一無窮大薄板，而太陽能晶片則為其中心位置上之一圓形區域，且晶片表面照度以軸對稱形式分布。我們再假設晶片上局部之光電轉換效率隨該點溫度上升而線性遞減(或晶片局部光電轉換效率之 “溫度係數” 為常數)，便可以解析方法推得此晶片與背板共構模組在穩態時之溫度分布，進而計算晶片之整體 (亦即空間平均)光電轉換效率。接著將晶片表面照度設為內外兩區分布，並且採用可在實際系統上實現之參數設定，我們有系統地檢視個別參數對於光電轉換效率的影響。結果顯示，晶片表面照度不均會導致其效率降低，但若能提升模組之散熱能力，同時選用溫度係數較低之太陽能晶片，則仍可將其轉換效率提升至更接近其理想 (最大) 值。
而為了得到均勻的晶片表面照度，我們也提出一項創新的聚光鏡設計。該設計以雙拋共焦反射鏡為主體，搭配適當焦距的Fresnel透鏡，入射的陽光經過二次光學後，可在晶片上得到相當均勻的照度分佈。因此該設計可有效降低因照度不均勻所引起的晶片效率損失，並且可以降低晶片的最高溫度，使晶片效率盡可能接近理論值。為了評估聚光鏡的各項特性，本文以數值模擬的方式探討局部最高聚光倍率、光學效率以及可接受角。此外，本文也針對幾何聚光倍率與寬高比深入討論，以決定如何透過調整兩者的設計值來求得較均勻的晶片照度，使晶片發揮較高的轉換效率。
為了確認雙拋反射式設計可有效降低晶片表面照度不均勻度，我們委託聚陽光能股份有限公司開發聚光倍率1040X之聚光型太陽能模組，並建立一套符合國際太陽能量測規範建議的測試平台。透過長時間的發電效能追蹤監控，當直射日照度高於800 W/m2時，其轉換效率常高於30%，由此足以證明該光學設計可有效解決晶片表面照度不均勻之問題。再搭配本文所建立之解析方法，預期本文之研究成果將可協助高倍率聚光型太陽能光電系統工程師優化其模組設計，應對其頗有助益。

Here we investigate how inevitable heating of a solar cell, resulting from its non-uniformly distributed surface irradiance, affects the conversion efficiency of a high-concentration photovoltaic (HCPV) module utilizing the solar cell. A 2-D model of heat transfer is considered to model the backsheet and solar cell which is subjected to axisymmetrically distributed surface irradiance. Assuming a constant temperature coefficient of the conversion efficiency, we can calculate the steady-state temperature distribution on the module analytically. The conversion efficiency of solar cell then is evaluated. Through a systematic and realistic parameter study for a two zone cell-surface irradiance distribution, it is demonstrated that cell-surface irradiance non-uniformity tends to decrease the conversion efficiency. And this emphasizes the importance of having a highly uniformly distributed irradiance on the cell surface.
In order to achieve uniform cell-surface irradiance, we then analyze the optical performance of a novel concentrator design. Specifically, in that design a pair of confocal parabolic reflectors and a Fresnel lens with matching focal length are employed to achieve high irradiance uniformity on solar cell. To evaluate the characteristics of this concentrator design, peak concentration ratio (PCR), optical efficiency and acceptance angle are calculated numerically. An optimized set of design parameters thus is identified. A confocal HCPV module then is constructed and tested, both in the lab and in the field. The results of testing clearly demonstrate the effectiveness of the concentrator design, and the high performance of the HCPV module.

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