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1 +,PSFBO4PD&OWJSPO&OH _ Original Paper IUUQTEPJPSH,4&& *44/F*44/ v h ò vod Evaluation of the Water Quality Changes in Agricultural Reservoir Covered with Floating Photovoltaic Solar-Tracking Systems *, * a * Ð ** j** Inju Lee Jin Chul Joo*, Chang Sin Lee* Ga Yeong Kim* Do Young Woo** Jae Hak Kim** s s vw}s} *s s p vw}s} **( ) g Department of Environmental Engineering, Hanbat National University *Department of Civil & Environmental Engineering, Hanbat National University **Solkiss Inc. (Received March 8, 2017; Revised March 20, 2017; Accepted April 4, 2017) Abstract : To evaluate the water quality changes in agricultural reservoir covered with floating photovoltaic solar-tracking systems, the water quality variations with time and depth were monitored on both six sites for light blocking zones and four sites for light penetration zones after the installation of floating photovoltaic solar-tracking systems in Geumgwang reservoir at Anseong-si, Kyeonggi province. For one year with 16 monitoring events, water quality parameters [i.e., water temperature, ph, dissolved oxygen (DO), chlorophyll-a (Chl-a), and blue-green algae (BGA)] were monitored at depths of 0.3 m, 1 m, 3 m, and 5 m, while chemical oxygen demand (COD), total nitrogen (TN), and total phosphorus (TP) were monitored at depths of 0.3 m. Statistically, the difference in all water quality parameters was not significantly different (p > 0.05) at the level of significance of Based on these results, the water quality data from light blocking zones (site 1~6) and light penetration zones (site 7~10) were clustered, and were compared with time and depth. As a result, the difference in water temperature, ph, DO, COD, TN, TP, Chl-a, and BGA between light blocking zones and light penetration zones was not significant (p > 0.05) with different time and depth. For Chl-a and BGA, some data from light blocking zones greater than light penetration zones were temporary observed due to the severe drought, low water storage rate, and over growth of periphyton. However, this temporal phenomenon did not impact the water quality. Considering the small water surface area ( 0.5%) covered by floating photovoltaic solar-tracking systems, the mixing effect of whole Geumgwang reservoir caused by Ekman current and continuous discharge were more dominant than the effect of reduced solar irradiance. Further study is warranted to monitor the changes in water quality and aquatic ecosystems with greater water surface area covered by floating photovoltaic solar-tracking systems for a long time. Key Words : Agricultural Reservoir, Floating Photovoltaic Solar-Tracking Systems, Water Quality Change, Solar Irradiance, Algae, Light Blocking. ² j m faj k Ð j m ô 6 4 j 1 Ò 16m Ù j m e j º. k, ph, DO, Chl-a, BGA k 0.3 m, 1 m, 3 m, 5 m j, h j COD, TN, TP k j º., 10 e Ù k ² m (p - value) 0.05 ( =0.05) º º j Ø º. j ¼ (site 1~6) (site 7~10) mn e ô m m j º. e, ph, DO, COD, TN, TP, Chl-a, BGA ô ² j j º º(p > 0.05). Chl-a BGA, 7 º Ða Ø ² a, Ù º j l j j j a ²ä Ø º. j ² m j ¼ 0.5% q n ² j mjn ¼ k ä dºùº. kn, j m p j k ² º j j j jä dºùº..,, m,,, 1. m (fossil fuel) j j i ô m a¼þø a³j Š am ¼ º. 1,2) Š Š ² ¼ b, n n j a mjj 3) Corresponding author jincjoo@hanbat.ac.kr Tel: Fax:

256 +,PSFBO4PD&OWJSPO&OH a Ð j ¼ k a³j î ² (photovoltaic systems) am¼j º. 2), 2000 ¼ a î k Š m Ñ j a Š j j k, 4) 2012 ² í Š jð mj² Š j¼ (renewable portfolio standards, RPS) Ð j m¼ j º.

2 256 +,PSFBO4PD&OWJSPO&OH a Ð j ¼ k a³j î ² (photovoltaic systems) am¼j º. 2), 2000 ¼ a î k Š m Ñ j a Š j j k, 4) 2012 ² í Š jð mj² Š j¼ (renewable portfolio standards, RPS) Ð j m¼ j º. 5) ô, l aj Š (28%), (52%), (63%), (79%), (45%) Þa jíø a Ð h p aj º. 6), Ða m Ð j p q o,, mî m Š m º² Ø º. 7) j (overland photovoltaic systems) mj, (floating photovoltaic systems) ² ¼ º. 7,8), m Ða m î j m o ¼j ¼ m a j, bn j ¼ 10% n ä Ø º. 7,9) j, j (solar radiation) ºj l (green tide) m, í (habitats) m ²È j a ² ä Ùº. 10) Ðj l ¼ j, k Ø² j j î k ¼j a Ø º. j l j m Ùm 1 j(monitoring) l l ² j º. ô ² Ù m ² m (floating photovoltaic solar-tracking systems) j j j m î ² k l 1 Ò j º. k, k Ø ² (light blocking zone) k ² (light penetration zone) m j n º j m j j ô m faj º ¼ ¼ ² Ð m ¼ ² p,, j î j Ù º. 11) m p j (1,520,000 m 2 ) 0.5%, e (24.8%) 1.9% 7,500 m 2 j, º (mv ) k j, º j jn j² 1,600 ê Ø º. 12) m a º j ô e m j e mø ¼ 22%, ¼ 17% Ð n } Ù º. 12) j, Ù a ô m k m } n j k q ¼j ² º. Fig. 1. 5IF DPODFQUVBM EFTJHO B BOE QJDUPSJBM WJFX C PG GMPBUJOH QIPUPWPMUBJD 17 TPMBSUSBDLJOH TZTUFNT FWBMVBUFE JO UIJT TUVEZ Journal of KSEE Vol.39, No.5 May, 2017

3 J. Korean Soc. Environ. Eng. 수상 회전식 태양광 발전시설 설치에 따른 농업용 저수지의 수질변화 평가 금광저수지 유역 현황 금광저수지는 경기도 안성시 금광면 금광리에 위치한 농 업용수를 저장 공급하기 위해 축조된 인공호로 유역면적 4,830 ha, 저수량 12,095,000 m, 관개면적 1,245 ha로 비교 적 규모가 큰 농업용 저수지이다. 금광저수지 인근 유역 은 토지계 유역면적의 비가 가장 높은 곳으로 인근에 위치 한 소규모 마을과 유락시설에서 배출되는 미처리된 일부 생 활계 오염원과 토지계와 축산계에서 배출되는 비점오염원 이 저수지로 유입되고 있는 것으로 보고되고 있다. 금광저수지의 수질현황 년 2011년부터 2015년까지 최근 5년간의 수질측정망자료 를 분석한 결과, 금광저수지의 수질은 호소수 수질환경기 준 IV등급으로 농업용수로 사용하기 적절한 것으로 조사되 었다. 최근 5년간 금광저수지의 수온은 5년 평균 16.1 ± 1.9 로 수온 변화는 계절적 변화가 뚜렷하고, 매년 유사한 주기성(periodicity)을 나타내고 있다. ph 값은 5년 평균 8.0 ± 0.1로 변화 폭이 크지 않았다. 화학적 산소요구량(COD)의 평균은 5.8 ± 0.5 mg/l로 다양한 요인과 계절적 영향에 의해 비교적 큰 변화 폭을 보이고 있으나, 일반적으로 여름철 저 수율이 감소함에 따라 COD 농도가 증가하는 경향을 보이 고 있다. 부유물질(SS) 농도는 평균 5.4 ± 0.8 mg/l로 강우 사상에 따라 편차가 큰 것으로 조사되었으며, 계절적 주기 성과 반복성(repeatability)을 확인할 수 없었다. 주요 영양염 류인 총질소(TN)와 총인(TP)의 평균은 각각 1.68 ± 0.1 mg/l, 0.04 ± mg/l로, 영양염류의 농도는 2011년을 제외한 2012~2015년 동안 통계학적으로 유사한 농도를 나타냈으 며, 금광저수지 유역의 오폐수배출시설의 고도화와 축산폐 수의 수거 및 처리를 통한 재이용으로 영양염류의 농도는 점차 감소하는 추세인 것으로 분석되었다. Chl-a의 평균 은 17.7 ± 3.8 µg/l로 영얌염류 농도 변화에 일부 영향을 받 는 것으로 조사되었으며, 5년 평균 Chl-a 농도가 호소수 수 질환경기준 III 등급으로 금광저수지 내 조류농도는 유사규 모의 다른 농업용 저수지 대비 다소 낮은 것으로 조사되었다 ) 13) (2011~2015 Table 1. Parameters Water temp. ph DO Chl-a ) 14) 15) 15) Fig. 2. Various water quality parameters and measurement methods at different water depth profiles 2.2. Water depth 0.3 m 1m 3m (water surface) Method 5m BGA COD TN TP Field measurement Laboratory measurement 측정 및 현장 채수 위치 수상 회전식 태양광 발전시설의 설치로 인한 차광 및 일 사량의 수체 내 유입 저하가 수질에 미치는 영향을 평가하 기 위하여 패널 중심을 기준으로 반경 300 m 내외에서 빛 이 차단되는 차광구역(light blocking zone, site 1~6) 6지점 과 비차광구역(light penetration zone, site 7~10) 4지점을 선 정하여 GPS 좌표를 이용해 동일 지점에서 1년 동안 수질을 장기적으로 측정 후 측정결과를 통계학적으로 분석하였다. 측정항목은 수온(water temperature), ph, 용존산소(dissolved oxygen, DO), 조류농도(chlorophyll-a, Chl-a와 blue-green algae, BGA)를 0.3 m(표층), 1 m, 3 m의 수심별로 각각 현 장에서 측정하였으며(Chl-a와 BGA는 수심 5 m 추가 측정), 기타 화학적산소요구량(chemical oxygen demand, COD), 총 질소(total nitrogen, TN), 총인(total phosphorous, TP) 분석 을 위해 차광구역(site 1~3) 3지점과 비차광구역(site 7, 8, 10) 3지점의 표층에서 시료를 채수하였다( ). Table 차광에 의한 수질 변화 측정 및 분석 방법 수질 측정 및 분석은 1월부터 11월에 걸쳐 총 16회 실시 하였으며, 월 1회를 기준으로 하되 수온이 상승하기 시작해 Pictorial view of floating photovoltaic (PV) solar-tracking systems and ten sampling sites for measurement and analysis of various water quality parameters. 대한환경공학회지 제39권 제5호 년 5월

m j m faj k (site 1~6) 6 (site 7~10) 4, 10 h È b (descriptive statistics) kj, g ¼, g Ðî d j kbox i m kjº 5%, 25%, 75%, 95%, s(o ), f s( ) º.

4 258 +,PSFBO4PD&OWJSPO&OH a Ð j º Ø²5 ~8 Ò 2m n1~3 kø º. l o ¼ j 1 Ò js f m j º. ²Multi 3420 Multiparameter (WTW, Cole-Parmer Co.) k m e j ºÙ 6 4, ph, DO (0.3, 1, 3 m) j, Chl-a BGA²Modern water (Modern water algae check) j 0.3, 1, 3, 5 m j º. l k l 1 L k Ð ma jh (0.3 m) j l p n f 2m j, l j ² l 17) ¼ COD² e, TN p Ð, TP² m j º m j m faj k (site 1~6) 6 (site 7~10) 4, 10 h È b (descriptive statistics) kj, g ¼, g Ðî d j kbox i m kjº 5%, 25%, 75%, 95%, s(o ), f s( ) º. j, ºe á j k2} º f j² á (one-way ANOVA) j 16 Ù j Ò j k ( )e (Ð ) a ² j á j º. i SPSS (ver. 22.0) j ANOVA kj, k e j a j, Scheff á j ná j º. í s j j (α = 0.05) º º a (H 0: µ st.1=µ st.2=µ st.3= µ st.4 µ st.10) n, ANOVA j b í a á j º. 18,19) nlm(2015 ) k ² (temperature) (radiation), v (precipitation) î ² ¼ m j º. 20) e 2015 f 13.5 f ¼ 1.5, e hr f ¼ hr º. v mm f ¼ mm, mm/day j a v Fig. 3. B1SFDJQJUBUJPO CTPMBSJSSBEJBODFBOE DXBUFSTUPSBHF SBUFT PG (FVNHXBOH BHSJDVMUVSBM SFTFSWPJS JO º(Fig. 3(a)). f, j ºv 7 29 j ²f ¼ m º(Fig. 3(b)). (water storage rate) } ²f s j, 2015 a k5 n jíq j º(Fig. 3(c) ). 9 v a k aj a º q jä Ø f ¼ f a ak mj ä dºùº (2015 ) (10 ) º j ¼s, s, f s, h f, Ò Table 2 j º. k (COD, TN, TP) 4 (site 4, 5, 6, 9) ² kj j, k¼ j kj º. b f 19.7 ± 0.03, ¼s s Þ js º. ph f 8.7±0.005, f Ð Þ Journal of KSEE Vol.39, No.5 May, 2017

5 +,PSFBO4PD&OWJSPO&OH m ô mfa 259 Table 2. %FTDSJQUJWF TUBUJTUJDT PG WBSJPVT XBUFS RVBMJUZ QBSBNFUFST BU FBDI PG (FVNHXBOH BHSJDVMUVSBM SFTFSWPJS JO 4JUFT 4UB UJTUJDT 8BUFS UFNQ p$ Q) %0 $0% 5/ 51 $IMB H- #(" H- 4JUFT 4UB UJTUJDT 8BUFS UFNQ p$ Q) %0 $0% 5/ 51 $IMB H- #(" H- /" /" /" /" /" /" /" /" /" /" /" /" /" /" /" /" /" /" /" /" /" /" /" /" /" /" /" /" /" /" /" /" /" /" /" /" /" /" /" /" /" /" /" /" /" /" /" /" /" /" /" /" /" /" /" /" /" /" /" /" 4 %4UBOEBSEEFWJBUJPO $PFGGJDJFOUPGWBSJBUJPO /"/PUBWBJMBCMF Fig w q fƒt ˆf pƒ fwt fƒfxp pƒ f pfhs t p xrˆfyr frƒth w ƒfw ƒp pƒ tƒ ty " ¼jm jm 39 5m

6 260 +,PSFBO4PD&OWJSPO&OH a Ð j º. DO f 11.8 ± 0.04 mg/l, ¼s s Þ j º. COD f 6.4 ± 0.05 mg/l, TN f 1.4 ± 0.06 mg/l, TP f 0.04 ± mg/l Ø º. Chl-a f 20.6 ± 0.8 µg/l, BGA f 27.8 ± 0.5 µg/l e j º. Ò (Cv) j,, (TN, TP), Ð(Chl-a, BGA) s ph, DO, (COD) ºf ¼ ¼ f a ä Ø º. ²,, Ð aph, DO, ¼ ma ¼ ä dºø, Ð j a Ø º. 21,22) (10 ) m j g ¼,, gðî d j j Boxplot j º. i jº s 5%, 25%, 75%, 95%, o s, f s, 8k (, ph, DO, COD, TN, TP, Chl-a, BGA) Þb f s jä º. j, b a ²ä b s ga º º dºùº. Table 3. 3FTVMUT PG "/07" BOBMZTJT GPS WBSJPVT XBUFS RVBMJUZ QBSBNFUFST JO UFSNT PG EJGGFSFOU TBNQMJOH T 1BSBNFUFST 4VNPG TRVBSFT EG.FBO TRVBSF ' 4JH 8BUFS UFNQ Q) %0 $0% 5/ 51 $IMB #(" 3.3. (ANOVA) (ANOVA), 8k (, ph, DO, COD, TN, TP, Chl-a, BGA) Þp-valuea0.05 º. k, º j í s j º º² j að Ø º(Table 3 ). j, b e m (p-value) ífaùä dº k 10} j º º faj, k j j º º dºùº k j (α = 0.05) º º Ø, j ¼ 6 4 bb mj e ô º j m Figs. 5~7 º. j aj, 6 ô a j l Ø ²Ñ j ä m j j² q j ²ä dºùº(fig. 5(a)). j Ð ô q ² ²ä Ø º. 23,24) phð j j a j, 5 a j aj² k h º 1 m Å º. ² Ðah ¼ 1 m Å Åä dºj aù m j j k - HCO 3 CO 3 2- OH - 1 m ph s ä dºùº(fig. 5(b)). 23) DOÐ j j j ², 5 ô DO q a Ø º(Fig. 5(c)). ²5 n j q j mj j j kj² Ò j a a Ø j l Ùº. 25) COD Ð²6 aj², 8 Ða ¼ s º(Fig. 6(a)). ² m j ºj, k COD a k dºùº. 26,27) TN TP ² eò m ² f º. TN TP Ð² j ² ä Ø º(Fig. 6(b), (c)). Journal of KSEE Vol.39, No.5 May, 2017

7 +,PSFBO4PD&OWJSPO&OH m ô mfa 261 Temperature ph Dissolved oxygen Etrs gw hvtyr yp Etrs pyp ƒf t y yp Fig. 5. 4yy fw fƒtf t ytyˆf pƒ px pƒf ƒp Afyi7Hgp ˆppywtrs gw hvtyr ypfyiwtrs pyp ƒf t y ypty@p xrˆfyr ƒp pƒ tƒ " Etrs gw hvtyr yp Etrs pyp ƒf t y yp Fig. 6.4yy fw fƒtf t yty6h7sgfyisigp ˆppywtrs gw hvtyr ypfyiwtrs pyp ƒf t y ypty@p xrˆfyrƒp pƒ tƒ " ¼jm jm 39 5m

8 262 +,PSFBO4PD&OWJSPO&OH a Ð j Etrs gw hvtyr yp Etrs pyp ƒf t y yp Fig. 7. 4yy fw fƒtf t y ty 6swf fyi 5@4 gp ˆppy wtrs gw hvtyr yp fyi wtrs pyp ƒf t y yp xrˆfyr ƒp pƒ tƒ " e 6 1 m Chl-a BGA Ða ¼ Ø, j l j ô j ¼ k qj a Òj dºùº. 28,29) Chl-a Ð² TP Ð m Òj jí, k ¼ m ² Chl-a TP a ² ä dºùº. 7 Chl-a BGA Ð² ¼ e s Ø ²È(Fig. 7), ² m k o kø, e m l jj m j dºùº. 30) j, Journal of KSEE Vol.39, No.5 May, 2017

9 +,PSFBO4PD&OWJSPO&OH m ô mfa 263 º l d j a k ¼ Ø dºùº. 26) Ða e í, j ²7 ²l ² k jä Ø º. ô m ô j n ² j dºùº. e, ph, DO, COD, TN, TP, Chl-a, BGA ² ² ä º º dºùº. ô e ô ² j º º Ø º. ² m 0.5% l j, m mjí k d ºÙº. j j m 23) Ð Ð a j j j, Ða jä m ² k Ñ ²ä j º. ô, Ø ² m 0.5% m ² k j ä dºø, m ô m º p j k ²¼ m ô ¼( ¼ 10% ) (3 ) j jä d ºÙº. 4. ¾ m, e j Ò ¼ jð j² ¼ n j j º² a Ø º. ² j m Ð j m ô 6 4 j 1 Ò 16m Ù j m e j º. m j,, (TN, TP), Ð(Chl-a, BGA) s ph, DO, (COD) ºf ¼ ¼ f a ä Ø º. (ANOVA), 8k (, ph, DO, COD, TN, TP, Chl-a, BGA) Þ p-valuea 0.05 kº j í s j º º² j a Ð Ø º. j ¼ (site 1~6) (site 7~10) m n e ô m m j, e, ph, DO, COD, TN, TP, Chl-a, BGA ô ² j j º º(p > 0.05). Chl-a BGA, 7 º Ða Ø ² a, Ù º j l j j j a ²ä Ø º. e º j ô a Ø ² m j ¼ 0.5% q n ² j mjn ¼ k ä dºùº. kn, m ô m º p j k ²¼ m ô ¼( ¼ 10% ) (3 ) j jä d ºÙº. References 1. Omer, A. M., Energy, environment and sustainable development, Renew. and Sust. Energy Rev., 12(9), 2265~2300(2007). 2. Won, C. S., Technical trend of floating PV system, J. Korean Solar Energy Soc., 13(1), 18~23(2015). 3. Park, J., Seager, T. P. and Rao, P. S. C., Lessons in riskversus resilience-based design and management, Integrated Environ. Assessment and Manage., 7(3), 396~399(2011). 4. Korea legislation research institute, Study on Promotion Legislation for New & Renewable Energy against Energy Crisis, (2011). 5. Lee, S. H., Lee, N. H., Choi, H. C. and Kim, J. O., Study on Analysis of Suitable Site for Development of Floating Photovoltaic System, J. KIIEE, 26(7), 30~38(2012). 6. Korea New and Renewable Energy Center, 2014 Renewable energy industry statistics, (2015). 7. Roh, T. H., Photovoltaic Business of the present condition and policy considerations, Environ. Forum, 19(6), 1~19(2015). 8. Choi, B. S., Jang, T. H., Kim, Y. I., Yoo, J. H. and Jang, H. Y., A study on the verification of the environmental safety in floating photovoltaic power system, in Proceedings of the annual meeting of Korean Society For New And Renewable Energy, KSNRE, Haeundae grand hotel, Busan, pp. 211~211(2015). ¼jm jm 39 5m

10 264 +,PSFBO4PD&OWJSPO&OH a Ð j 9. Choi, Y. K., A Study on Power Generation Analysis of Floating PV System Considering Environmental Impact, Int. J. Software Eng. and Its Appl., 8(1), 75~84(2014). 10. Korea National Environmental Technology Information Center, Technical trend of floating PV system, (2016). 11. Korea Rural Community Corporation, Investigation of water pollution source in the waterside area in geumgwang reservoir, (2008). 12. Solkiss, Comparison analysis of Photovoltaic system, (2015). 13. Won, S. J., Water Quality Forecasting in Geumgwang Reservoir using WASP5 Model, Master dissertation, The graduate school of technology Hankyong National University, Korea(2008). 14. Agriculture water total information system (RAWRIS) Home Page, Dec.(2015). 15. Ministry of Environment, environmental standard for water quality, (2016). 16. Lee, I. J., Evaluation of the water quality changes in agricultural reservoir covered with floating photovoltaic solartracking systems, Master dissertation, The graduate school of Hanbat National University, Korea(2017). 17. Ministry of Environment, Official test method enacted by Korean Ministry of Environment, (2016). 18. Antonio, C., Manuel, F. and Ricardo, F., An anova test for functional data, Computational Statistics & Data Anal., 47 (1), 111~122(2004). 19. Kim, J. H., Lee, S. W. and Cha, S. M., Environmental statistics and data analysis, Hannarae Publishing Co., Seoul, pp. 55~243(2016). 20. Korea Meteorological Administration, 2015 Annual climatological report, (2016). 21. Kim, J. M., Park, J. D., Noh, H. R. and Han, M. S., Changes of Seasonal and Vertical Water Quality in Soyang and Paldang River-reservoir System, Korea, Korean J. Limnol., 35(1), 10~20(2002). 22. Kim, H. S. and Hwang, S. J., Seasonal Variation of Water Quality in a Shallow Eutrophic Reservoir, Korean J. Limnol., 37(2), 180~192(2004). 23. Lee, Y. W. and Lee, H. Y., Effects of Light-Blocking on Water Quality and Phytoplankton Community in Lake Juam, Korean J. Limnol., 36(2), 150~160(2003). 24. Larry, L. L. and Shane, L. L., Riparian Shade and Stream Temperature, Rangelands, 18(4), 149~152(1996). 25. Kang, Y. M. and Song, H. G., Effect of sediment organic in Pond Yeonjukji matter on the oxygen consumption, J. Basic Sci., 10, 74~79(1999). 26. Jeon, J. H., Yoon, C. G., Ham, J. H., Kim, H. I. and Hwang, S. J., Effects of Physical Parameters on Water Quality in Agricultural Reservoirs, Korean J. Limnol., 35(1), 28~35 (2002). 27. Kim, H. J., Yoon, K. S. and Lee, K. S., Characteristics of the Water Quality of Wanggung Agricultural Reserivor, J. KCID, 10(2), 24~35(2003). 28. Allan, K. and Thomas, D. B., Effect of Temperature on Blue-Green Algae (Cyanobacteria) in Lake Mendota, Appl. and Environ. Microbiol., 36(4), 572~578(1978). 29. Park, J. W., Yu, S. H., Lee, J. E. and Seo, E. W., Dynamics of Phytoplankton Community by the Water Depth in Andong Reservoir, J. Life Sci., 18(9), 1249~1256(2008). 30. Lee, J. W., Kim, H. J. and Cho, Y. S., A Numerical Model for Wind-Induced Circulation in a Thermally Stratified Flow, J. Korea Water Resour. Assoc., 43(10), 911~920(2010). Journal of KSEE Vol.39, No.5 May, 2017

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