task 7bb report philippine renewable energy project
TRANSCRIPT
-
8/10/2019 Task 7Bb Report Philippine Renewable Energy Project
1/24
-
8/10/2019 Task 7Bb Report Philippine Renewable Energy Project
2/24
Dave Renn
Pamela Gray-HannRay George
Liz Brady
1. Introduction
Accurate solar resource data is important for the proper sizing and life cycle cost analysisof solar photovoltaic technologies. Knowledge of the spatial distribution of the solar
resource for various tilt angles will allow for more cost effective design and operation ofphotovoltaic systems for meeting small, distributed loads. The goal of this task is to
develop a solar assessment for the Philippines that incorporates and builds upon current
understanding of the spatial distribution of the resource. This assessment provides datathat developers and investors can use to help establish successful business activity in off-
grid solar technologies in the Philippines.
Although solar resource assessments have been conducted for the Philippines, these
generally make use of ground-based measurements of the daily total number of hours of
sunshine duration. The updated assessment provided here combines existing ground
measurement data collected in the Philippines with the output of NRELs ClimatologicalSolar Radiation (CSR) Model. This model converts information on satellite- and surface-
derived cloud cover data collected at a 40-km spatial resolution to estimates of the
monthly average daily total global horizontal solar resource. This spatial resolution isgenerally much higher than the spacing of ground stations, and therefore allows for a
more detailed analysis of the effects of microclimate variability on the solar resource, and
provides a more accurate interpolation of the solar resource between ground stations.
-
8/10/2019 Task 7Bb Report Philippine Renewable Energy Project
3/24
Puerto Princesa (#618), 1984-1997 (missing: January 1985, April, May 1988).
Tuquegarao (#233), 1975-1997 (missing: Feb., May Dec. 1985, all months for 1986-
1987, Jan. Aug. 1988, Feb. 1991).Catarman (#546), 1970-1986, 1987-1995
Laoag (#223), 1970-1985, 1986-1995 (missing: March, April 1985; May August
1988).Victoria's Milling Corporation (#618c), 1971-1982, 1983-1995 (missing: Sept., Oct.
1987; Jan. 1988, April, May, 1991).
Global Horizontal data for the following cities and dates:
Victoria's Milling Corporation, 1984-1995
Quezon, 1972-1989, 1994-1996 (also known as Science Garden)
Each of the stations (except Catarman, Baguio, and Cagayan de Oro) with the sunshine
recorder data also have global horizontal measurements, either collected with a bimettalicstrip device (Laoag and Tacloban) or with a pyranometer (the four remaining stations).
However, these data were not included with the electronic data, and were not available
for this study.
The list of PAGASA solar radiation stations that provided by PAGASA shows many
additional stations with global horizontal measurements, using pyranometers. These
stations are:Basco
Echague, Isabela
La Trinidad, BenguetCasiguran, Quezon
Munoz, Nueva Ecija
Iba, Zabales
-
8/10/2019 Task 7Bb Report Philippine Renewable Energy Project
4/24
2.2 Report: The Profile of Solar Insolation in the Philippines
The report The Profile of Solar Insolation in the Philippines provides tables and maps
of monthly average global horizontal solar resource data based on stations with actual
solar measurements as well as stations that have only sunshine recorders or cloud coverobservations. For the latter types of stations, empirical techniques such as a modification
of the Angstrom relation were used to develop solar resource estimates. The reportshows 17 stations with some form of solar measurement (Kahlisco pyranometer, Licor
Pyranometer, or other such as bimetallic strip recorder), where data collected in the early1980s are used. Seven of these stations also have sunshine recorders, which allows for
the development of the Angstrom coefficients. Data for 65 stations where sunshine
recorders or cloud cover observations are made are also provided.
2.3 UMASS/Lowell Data Report
In 1991 the University of Lowell Photovoltaic Program developed an international solarradiation data base, providing monthly average daily total solar radiation data for
numerous stations around the world. Most of the data were derived from sunshine
recorders. The report shows a total of fifteen stations for the Philippines.
-
8/10/2019 Task 7Bb Report Philippine Renewable Energy Project
5/24
3. Description of the Climatological Solar Radiation Model
The modeling approach that was developed for the production of the U.S. National Solar
Radiation Data Base (NSRDB 1993) was modified to provide large area, high spatial
resolution of solar resources using a global satellite-derived cloud cover data base. Theoriginal model, METSTAT (Maxwell 1998a), calculates atmospheric extinction for clear-
sky and cloudy conditions using inputs of opaque and translucent cloud cover derived
from ground observations, precipitable water vapor, ozone, and aerosol optical depth.The output, then, is hourly values of surface direct normal, global horizontal, and diffuse
solar radiation. The METSTAT model was modified to generate monthly average dailytotal values of the three elements for each Real-Time Nephanalysis (RTNEPH) grid cell.
The modified model is known as the Climatological Solar Radiation (CSR) model(Maxwell, George, and Wilcox 1998b). The RTNEPH data use ground-based cloud
cover observations where available (generally, these are three-hourly observations
obtained from national weather services around the world), and Polar OrbitingEnvironmental Satellite imagery to interpolate between the stations. Although the world-
wide RTNEPH data are available on a three-hourly basis for a period beginning 1
August, 1983, the version of the data used in the CSR model is a histogram data basecovering the period from 1985 to 1992. The histograms of total cloud cover for hours
between sunrise and sunset were used to determine monthly average total cloud cover
during daytime hours. The histograms for low, middle, and high cloud layers were used
to estimate monthly average opaque cloud cover.
The CSR model has been run for a number of regions around the world, including the
entire east Asia region. The Philippines were included in the east Asia calculations, andthe results of these calculations form the basis of the modeled assessment provided here.
Preliminary evaluations of the monthly average daily total model output for several
locations around the world show agreement with ground stations between 5 - 15%, with
-
8/10/2019 Task 7Bb Report Philippine Renewable Energy Project
6/24
It was noted in Figures 2 through 14 that two ground stations are available with which to
compare the CSR model data grid values. Here, inFigures 17-18,we see profiles of themonthly values comparing the ground station with the corresponding CSR model data
grid value. The figures show that, particularly at Science Garden, the CSR model tends
to produce slightly higher values than the ground observation. However, it is importantto note that the data grid represents the average resource over a 1600 km
2, while the
ground station is a point value, which could be valid throughout some portions of the
area.
6. Summary and Conclusions
The results of this analysis shows that the CSR model output provides results that arecomparable to values obtained from surface stations. However, the CSR model is
capable of providing higher resolution data than the ground network. Nevertheless, the
spatial variation of the solar resource across the Philippines in any given month is low(approximately 10% to 20%), while the variation between the wet and dry seasons is
quite high (30% to 50%).
7. References
Maxwell E. L., METSTATthe solar radiation model used in the production of the
National Solar Radiation Data Base (NSRDB). Solar Energy62, 4, 263-279, (1998a).
Maxwell, Eugene L., Raymond L. George, and Stephen M. Wilcox, A ClimatologicalSolar Radiation Model,Proceedings of the 1998 Annual Conference, American Solar
Energy Society, Albuquerque, pp. 505-510, June 14-17, (1998b).
University of Lowell Photovoltaic Program, 1991: International Solar Irradiation
Database Version 1 0 University of Lowell Research Foundation 450 Aitken Street
-
8/10/2019 Task 7Bb Report Philippine Renewable Energy Project
7/24
-
8/10/2019 Task 7Bb Report Philippine Renewable Energy Project
8/24
Victorias, Negros, Occ., #618C
Comparison of CSR Model Values with Measured Data
(1985 to 1991)
0.0
2.0
4.0
6.0
8.0
10.0
12.0
January
Fe
bruary
Marc
h
Apri
l
May
June
Ju
ly
Augus
t
Sep
tem
ber
Oc
tober
Novem
ber
Decem
ber
kWh/m2/day
CSR
Measured
-
8/10/2019 Task 7Bb Report Philippine Renewable Energy Project
9/24
-
8/10/2019 Task 7Bb Report Philippine Renewable Energy Project
10/24
-
8/10/2019 Task 7Bb Report Philippine Renewable Energy Project
11/24
-
8/10/2019 Task 7Bb Report Philippine Renewable Energy Project
12/24
-
8/10/2019 Task 7Bb Report Philippine Renewable Energy Project
13/24
-
8/10/2019 Task 7Bb Report Philippine Renewable Energy Project
14/24
-
8/10/2019 Task 7Bb Report Philippine Renewable Energy Project
15/24
-
8/10/2019 Task 7Bb Report Philippine Renewable Energy Project
16/24
-
8/10/2019 Task 7Bb Report Philippine Renewable Energy Project
17/24
-
8/10/2019 Task 7Bb Report Philippine Renewable Energy Project
18/24
-
8/10/2019 Task 7Bb Report Philippine Renewable Energy Project
19/24
-
8/10/2019 Task 7Bb Report Philippine Renewable Energy Project
20/24
-
8/10/2019 Task 7Bb Report Philippine Renewable Energy Project
21/24
-
8/10/2019 Task 7Bb Report Philippine Renewable Energy Project
22/24
-
8/10/2019 Task 7Bb Report Philippine Renewable Energy Project
23/24
-
8/10/2019 Task 7Bb Report Philippine Renewable Energy Project
24/24
Science Garden, #430
Comparison of CSR Model Values with Measured Data
(1985 to 1991)
0.0
2.0
4.0
6.0
8.0
10.0
12.0
January
Fe
bruary
Marc
h
Apri
l
May
June
Ju
ly
Augus
t
Sep
tem
ber
Oc
tober
Novem
ber
Decem
ber
kWh/m2/day
CSR
Measured