Simon Furbo, Louise Jivan Shah and Louise Overvad Jensen
Department of Civil Engineering
Technical University of Denmark
Building 118, DK-2800 Kgs. Lyngby
Denmark

Email: sf@bvg. dtu. dk
Fax: +45 45 93 17 55

Esben Larsen
0rsted. DTU

Technical University of Denmark
Building 348, DK-2800 Kgs. Lyngby
Denmark

Email: ela@.oersted. dtu. dk

Goran Olsson
Sunarc A/S

Gronlandsvej 14, DK-4681 Herfolge
Denmark

Email: olsson@sunarc. net

1 INTRODUCTION

Experiments have shown that an antireflection surface of a glass cover can increase the transmittance by reducing the normal 4 % reflection at the air-glass interface [1]. Different techniques of the antireflection treatments are sol-gel deposition [2], direct plasma enhanced chemical vapor deposition [3] and acid etching of the glass [4].

The company SunArc A/S applies an antireflection surface to the glass by a special etching process.

Investigations have shown that for incidence angles between 0° and 70° the solar transmittance of a glass cover is increased by 5-9 %-points and the efficiency of a flat plate solar collector is increased by 4-6 %-points by using a glass cover equipped with antireflection surfaces by the company SunArc A/S, [5].

In this paper measurements of the efficiency for a marketed PV module with the normally used glass cover and with the same glass cover after an antireflection treatment of the outer surface of the glass by SunArc A/S are presented.

The efficiency of the PV module was measured outdoors under different weather
conditions: For sunny periods with a small part of the radiation being diffuse
radiation and with incidence angles for the direct radiation of 0°, 15°, 30°, 45°, 60°

and 75°, and for cloudy periods with a small part of the radiation being direct radiation.