AUTHOR/S: Randell U. Espina
DATE COMPLETED:
KEYWORDS: Solar, Photovoltaic, Optimal, Design, Grid-Interactive
ABSTRACT
The study intends to understand the operation, the economic viability and the potential of a solar power technology to satisfy the electricity needs of the future. A 13.44-kW grid-interactive solar-PV energy system was installed at the roof deck of the Finster building of the Ateneo de Davao University, Jacinto Campus, Davao City, Philippines with a GPS location of 7.072 N° and 125.613 E°. For optimal energy production, a tilt angle of 22° and azimuth angle of -4° was used which predicted a high incident solar radiation for the months of March and October valued at 5.43 and 5.44 kWh/m2/day, respectively. The actual collected incident solar radiation reached 138.9 kWh/m2 within a 30-day period wherein a peak value of 7.26 kWh/m2 on a single day was detected.
Four sub-inverters were used in which sub-inverter 1 (gt1) performed better than the other three sub-inverters. The difference in performance was influenced mainly by the “System Availability” (SA) and “Inverter & Transformer” (IT) parameters. SA is a derating parameter that represents the readiness of the solar-PV system to produce solar electricity at any given time when there is available sunlight and when all components are all functioning. On average, SA was 69.50% with the sub-inverter 1 (gt1) providing the highest availability at 82.70% and sub-inverter 2 (gt2) with the lowest availability at 63.40%. IT is also a derating parameter which reflects the efficiency of the sub-inverters and their corresponding transformers. Sub-inverter 1 (gt1) has the highest efficiency at 92.50% while the other sub-inverters had efficiency around 89.00% each.
With the observed performance of the sub-inverters, the overall daily energy production was diminishing at a rate of 0.0098. Sub-inverter 1 (gt1) experienced the slightest reduction at 0.0076 and sub-inverter 2 (gt2) experienced the highest slump at 0.0129. Aside from the decline, the predicted average daily energy production was lower by 18.30% in which sub-inverter 1 (gt1) out-performed the other sub-inverters (gt2, gt3, and gt4).
Using the predicted values, a solar-chart was developed to determine the optimal tilt and azimuth angles that can be used in a particular location. By measuring the intensity of solar radiation at 11:00AM and multiply it with 11.24 and 2/3, the solar radiation on a certain day can be found. With the estimated solar radiation on any day, multiply it by 10 (13.44kW x 74.4%) to obtain the expected energy production. The technique described above will help simplify in designing a solar-PV energy system.
For optimal design of a grid-interactive solar-PV energy system, aside from sizing and selection of optimal tilt and azimuth angles, it is a requisite to suitably choose the right solar-PV modules and inverter. With the optimized design and increasing efficiency of solar-PV cells, the overall cost will be minimized and harvesting of solar radiation can be maximized. Once the acquired knowledge will be put into practice, solar power technology seemed to be a good source of electricity for Universities and the general electric consumers now and for the future.
Request for Full Article (Please fill in the needed details. We will promptly respond to your request thru your e-mail.)
[contact-form-7 404 "Not Found"]