# A Misalignment Optical Guiding Module for Power Generation Enhancement of Fixed-Type Photovoltaic Systems

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## Abstract

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## 1. Introduction

^{2}of solar irradiation in a day [1]. Abbot showed that this amount of irradiation could generate around 85,000 TW and estimated that the current global energy consumption was about 15 TW [2]. However, the cost of PV systems is high, and this is a barrier in competing with conventional electricity technologies. Therefore, studies on solar concentrators are becoming more and more common. These devices can concentrate solar radiation onto a small area, and the size of the PV cell can be reduced. Also, the cost of the PV system can be reduced. A previous study indicated a cost reduction of 40% using a solar concentrator with a geometrical concentration ratio of 2.45 [3]. Also, a normal PV cell may have higher conversion efficiency under concentrated solar radiation [4].

## 2. Experimental Methods

#### 2.1. Non-Axisymmetric Compound Parabolic Curve Design

#### 2.2. Freeform Surface Collimator Design

## 3. Results and Discussion

#### 3.1. The Simulation Results of the NACPC

#### 3.2. Simulation Results of the Freeform Surface Collimator

#### 3.3. Analysis of the Misalignment Light-Guiding Unit

#### 3.4. The Misalignment Light-Guiding Unit Array

#### 3.5. The Misalignment Light-Guiding Unit Array

^{2}. All experimental set-ups had a resistance of 2.2 kΩ connected in series. The set-up is shown in Figure 28, and the experimental results are shown in Figure 29. The results showed that the CPC combined with the collimator had the largest power generation compared to the naked PV panel and the CPC. It was estimated that the CPC with the collimator had 37% higher power generation than the naked PV panel, while the CPC had 24% higher power generation.

^{2}) and Figure 29 (90 mm

^{2}) were different; thus, the power was affected.

## 4. Conclusions

## Author Contributions

## Funding

## Conflicts of Interest

## References

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**Figure 3.**The principle behind the CPC, (

**a**) definition of the half-acceptance angle, (

**b**) incident angle smaller than the half-acceptance angle, (

**c**) incident angle equal to the half-acceptance angle, (

**d**) incident angle larger than the half-acceptance angle.

**Figure 11.**The parameters and appearances of the (

**a**) mirror-CPC, (

**b**) solid-CPC, (

**c**) mirror-NACPC, and (

**d**) solid-NACPC.

**Figure 12.**The irradiance distribution of the mirror-CPC with misalignment angles of (

**a**) 0°, (

**b**) 10°, (

**c**) 20°, and (

**d**) 30°.

**Figure 13.**The irradiance distribution of the solid-CPC with misalignment angles of (

**a**) 0°, (

**b**) 10°, (

**c**) 20°, and (

**d**) 30°.

**Figure 14.**The irradiance distribution of the mirror-NACPC with misalignment angles of (

**a**) 0°, (

**b**) 10°, (

**c**) 20°, and (

**d**) 30°.

**Figure 15.**The irradiance distribution of the solid-NACPC with misalignment angles of (

**a**) 0°, (

**b**) 10°, (

**c**) 20°, and (

**d**) 30°.

**Figure 16.**The irradiance distribution of other lateral orientations at (

**a**) 0°, (

**b**) 15°, and (

**c**) 20°.

**Figure 18.**The results of the freeform surface collimators: (

**a**) the ray trace and (

**b**) the irradiance distribution of the TIR collimator; (

**c**) the ray trace and (

**d**) the irradiance distribution of the elliptical collimator; (

**e**) the ray trace and (

**f**) the irradiance distribution of the new TIR collimator; (

**g**) the ray trace and (

**h**) the irradiance distribution of the new elliptical collimator.

**Figure 19.**The four cases and sizes of misalignment light-guiding units: (

**a**) the mirror-NACPC with the TIR collimator; (

**b**) the mirror-NACPC with the elliptical collimator; (

**c**) the solid-NACPC with the new TIR collimator; (

**d**) the solid-NACPC with the new elliptical collimator.

**Figure 20.**The irradiance distribution of the mirror-NACPC and the TIR collimator with misalignment angles of (

**a**) 0°, (

**b**) 10°, (

**c**) 20°, and (

**d**) 30°.

**Figure 21.**The irradiance distribution of the mirror-NACPC and elliptical collimator with misalignment angles of (

**a**) 0°, (

**b**) 10°, (

**c**) 20°, and (

**d**) 30°.

**Figure 22.**The irradiance distribution of the solid-NACPC and new TIR collimator with misalignment angles of (

**a**) 0°, (

**b**) 10°, (

**c**) 20°, and (

**d**) 30°.

**Figure 23.**The irradiance distribution of the solid-NACPC and new elliptical collimator with misalignment angles of (

**a**) 0°, (

**b**) 10°, (

**c**) 20°, and (

**d**) 30°.

**Figure 26.**The irradiance distribution of the misalignment light-guiding unit array at misalignment angles of (

**a**) 0°, (

**b**) 10°, (

**c**) 20°, and (

**d**) 30°.

**Figure 28.**The experimental set-up: (

**a**) the naked photovoltaic (PV) panel; (

**b**) the CPC; (

**c**) the CPC with the collimator.

**Figure 30.**The experimental results of the two-dimensional (2D) prototype: (

**a**) the naked PV panel; (

**b**) the NACPC; (

**c**) the NACPC with the new elliptical collimator.

**Figure 31.**The experimental results of the 2D prototype of the NACPC with the new elliptical collimator.

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**MDPI and ACS Style**

Pan, C.-T.; Yen, C.-K.; Wang, S.-Y.; Sun, P.-Y.; Huang, S.-Y.; Hwang, Y.-M.; Liu, Z.-H.; Chu, L.-M.; Hoe, Z.-Y.
A Misalignment Optical Guiding Module for Power Generation Enhancement of Fixed-Type Photovoltaic Systems. *Micromachines* **2019**, *10*, 687.
https://doi.org/10.3390/mi10100687

**AMA Style**

Pan C-T, Yen C-K, Wang S-Y, Sun P-Y, Huang S-Y, Hwang Y-M, Liu Z-H, Chu L-M, Hoe Z-Y.
A Misalignment Optical Guiding Module for Power Generation Enhancement of Fixed-Type Photovoltaic Systems. *Micromachines*. 2019; 10(10):687.
https://doi.org/10.3390/mi10100687

**Chicago/Turabian Style**

Pan, Cheng-Tang, Chung-Kun Yen, Shao-Yu Wang, Pei-Yuan Sun, Sin-Yu Huang, Yeong-Maw Hwang, Zong-Hsin Liu, Li-Ming Chu, and Zheng-Yu Hoe.
2019. "A Misalignment Optical Guiding Module for Power Generation Enhancement of Fixed-Type Photovoltaic Systems" *Micromachines* 10, no. 10: 687.
https://doi.org/10.3390/mi10100687