Impact Assessment of Roof-Mounted Grid-Tied Photovoltaic System at the Climate Change Center Building, ISU, Echague, Isabela

Authors

  • Sabas V. Lazaro College of Engineering, Isabela State University, Philippines
  • Januel P. Floresca Isabela State University, Echague Isabela

Keywords:

carbon offset, climate change mitigation, exported power, generation power, roof-mounted grid-tied photovoltaic system (GTPVS)

Abstract

A 20-kW roof-mounted grid-tied photovoltaic system (GTPVS) installed at the Climate Change Center building was
assessed in terms of its actual power generated, grid power and electric bill reduction and contribution to climate change
mitigation. Running power from ordinary electricity meter was 0.4 kW/sec. Input current and voltage with running heavyload equipment (5 tonner aircon, 600 watts server and workstations) were 40.5-98.8 A and 234-235 V, respectively,
yielding 9.5-23.12 kW power range. Daily generation power ranged between 5 and 10 kW from 7am to 3pm. Daily
exported power reached as high as 30 kW. Exported energy was highest in 2019 at 70 MWh that was dumped to avoid
added kWh readings payable by the University. Electric consumption ranged from 1,011 kwh in January 2020 (cold
season) to 2,562 kwh in April 2019 (summer season). Indicative electric bill reduction was P32,677 from 4,736 to 1,237
kWh power reduction resulting to a 5 years payback period for the P2M GTPVS investment. Cash flow analysis over 25
years life span indicated an The P2M worth roof-mounted GTPVS indicated an NPV, BCR, IRR and break even of
P896,717, 1.33, 16.27% and 7-8 years, respectively considering 10% discount rate and P10,000 scrap value on declining
balance depreciation. Carbon offset was 41.71 tons equivalent to 112 trees planted since it was commissioned in
December 11, 2017. Roof durability due to PV panel railings was also observed since it withstood a 180 kph strong
typhoon “Rosita” in October 2018.

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Published

2020-12-15