本文へジャンプ

成果報告書詳細
管理番号20180000000062
タイトル*平成27年度中間年報 高性能・高信頼性太陽光発電の発電コスト低減技術開発 共通基盤技術の開発(太陽光発電システムの信頼性評価技術等) 太陽光発電の寿命予測ならびに試験法の開発(屋外曝露モジュールの分析による加速試験法の開発)
公開日2018/6/26
報告書年度2015 - 2015
委託先名東レ株式会社
プロジェクト番号P15003
部署名新エネルギー部
和文要約
英文要約Title:Prediction of lifetime and development of test methods for photovoltaic modules (Clarification of degradation phenomena and development of accelerated test methods for photovoltaic modules) (FY2015-FY2017) FY2015 Annual Report

1. Investigation for exposure environment
"UV" and "hygrothermal" stress is considered to be cause of crack of backsheet(BS), which degrade electrical safety of the PV module. We have studied these effects.
A.UV stress
We use albedo in estimating UV stress for BS, though it is not clear whether use albedo is applicable. We tested with flooring materials whose reflectance are already known. We measured amount of UV irradiation for front and back of PV module. Measured UV stress ratio of BS to front was 10%, though average reflectance of the flooring material was 30%. Also we verified there was no seasonal difference. These results show UV stress for BS is lower than albedo. Therefore, measured UV stress is important in developing the accelerated test for BS.
B.Hygrothermal stress
It is generally known that temperature of PV module is higher than ambient temperature. Damp heat test(DHT) is standard hygrothermal test for BS or PV module, but sample temperature is equal to ambient temperature under DHT condition. We carried out two kinds of tests with PET film. We installed heater in the testing chamber in order to make sample temperature higher than ambient temperature (test1). Then, we thought hygrothermal stress was estimated by amount of vapor in testing chamber. Estimated humidity and heater temperature were set in another testing chamber (test2). Degradation behavior was evaluated by measuring elongation. The results showed similar degradation behavior. This means the hygrothermal stress to sample between test1 and test2 is same. Then, it is suggested that hygrothermal stress for BS integrated in PV module can be estimated by module temperature and vapor amount of environment.

2. Analysis of field exposure module
We analyzed used module in order to compare acceleration test and field degradation. Used module was exposed for 5 years. Composition of BS is white PET/Transparent PET. We analyzed two parts of BS; one is the center of the module and the other is BS under product label. Product label highly shields BS from light, therefore BS under product label is thought not to be affected by UV stress. GPC measurement resulted in small decrease of molecular weight only in the vicinity of surface of white PET. This result shows UV stress for white PET is not uniform. This is thought to be due to light shielding by the pigment.

3. Development of multiple accelerated test
In realizing 100 times of acceleration factor, we have to cause 30 years stress in 110 days. In order to shorten the test time, we evaluated how long it needs to cause similar degree of hygrothermal stress to sample in more severe condition. We used PET film as samples. As a result, we verified 100h of 105℃100%RH and 24h of 121℃100%RH are equivalent to DHT1000h.
ダウンロード成果報告書データベース(ユーザ登録必須)から、ダウンロードしてください。

▲トップに戻る