Hawaii Based Crystalline & Thin Film PV Performance Test Underway!

Beachside Solar Technologies is pleased to announce installation of the first photovoltaic test array in Hawaii that is comprised of both crystalline PV and amorphous thin film PV modules in a side by side configuration and designed to provide test data only. The test array, installed on the Big Island of Hawaii, was designed and built by Beachside Solar Technologies as a Hawaii based test bed to model electrical output performance on crystalline silicone (c-Si) photovoltaic technology and amorphous thin film (a-Si) photovoltaic technology.

There have been many tests of crystalline and amorphous thin film photovoltaic technologies at various locations worldwide, but never in a test bed array, located side by side in the state of Hawaii. There has been much controversy and confusion regarding the production and efficiency differences between crystalline and amorphous thin film photovoltaic technologies. Many people that are considering installing a photovoltaic system on their homes or businesses end up confused and not knowing what to believe when it comes to choosing a particular photovoltaic technology type. This photovoltaic system test bed allows us to remove the human opinion element from this controversy and provide a potential customer with current scientific data gathered on the ground in Hawaii’s unique climate and geographic location. Equipped with this data, they can then make an informed decision on which photovoltaic system will best suit their particular requirement and application.

The Photovoltaic Test Array Site
Most photovoltaic system integrators in Hawaii are aware of the multitude of microclimates located around the state. On each island the weather and climate can change dramatically in a very short distance. Because of these diverse microclimates, photovoltaic system output modeling must be done utilizing weather data sets for the particular latitude and longitude where the photovoltaic array will be located. The Windward and Leeward sides of the islands are the principal climatic division, with smaller microclimates located upslope on both sides of the islands. Because most of the state’s population is located at lower elevations near the seashore, we decided it best to locate the test array at an average low elevation location. We also thought it would be best to gather data on both the windward and leeward sides of the island chosen to host the test array. The initial installation was on the leeward side of the Big Island in Kailua-Kona, with data gathered during the month of July, 2010.

In early August 2010 the test array was moved to its permanent location in Hilo, on the windward side of the Big Island.

The original site for the test array on the leeward side of the Big Island, at Kailua-Kona, was at an elevation of 326 feet. The Kona test site location was chosen because of its typical leeward climatology and because it was a secure location. Being generally hot and arid, the typical weather pattern of the Kona side of the Big Island is afternoon mauka (mountain) cloudiness that starts building on the slopes in the afternoon, which sometimes produces showers in the mid and upper elevations. This weather cycle is typical for the leeward slopes of most of the islands of Hawaii, as well as the southern shores of the islands. This made the Kona site a good place to situate the array.

In addition to the weather cycle found on the Kona side of the Big Island, the climatology is impacted by the continuing eruption of Kilauea volcano, and the volcanic fog (Vog) produced by it. Because of the predominant wind patterns, the Kona area is regularly affected by Vog. On most days the Vog creates a layer that varies from a light haze to a thick smoke like concentration. The higher the concentration of Vog, the less sunlight that makes it to the ground. Vog has negatively affected the performance of photovoltaic systems located in the Kona area, particularly crystalline photovoltaic systems. By locating the photovoltaic test bed in the Kona area, we were able to effectively gather output and performance data on both photovoltaic technology types, in low and obscured light conditions.

After providing data during month of July 2010, the test array was moved to its permanent location in Hilo, on the windward side of the Big Island of Hawaii. It is located at the 180 foot elevation, in a secure site. Hilo was chosen as the permanent site for the test array, due to the varied climatology that is found there. The Hilo area is typical of most windward areas of the Hawaiian Islands, with many rain days. Hilo is also affected by Vog from time to time, whenever the island experiences “Kona Winds” from the southwest.

The Photovoltaic Test Array Configuration
The equipment chosen for the Hawaii based photovoltaic test array are common system components from major manufacturers, and readily available worldwide. Our goal was to build a test array of common photovoltaic system components as close to the same rated DC system size as possible.

Following are the photovoltaic test array equipment components:

• Crystalline Modules:  15pc Sharp ND-224U1F (3360 watts)
• Thin Film Modules:  24 pc Unisolar PVL-144 (3456 watts)
• Crystalline Module Mounting: ProSolar Racking
• Thin Film Module Mounting: Self-Adhered Modules On TPO Single Ply Membrane Mechanically Attached To Metal Deck
• Array Azimuth:  150 degrees
• Array Pitch:  14 degrees
• Inverters:  SMA Sunny Boy Model SB4000US
• Data Logger: Onset Computer HOBO U30-WIF Cellular Remote (15 minute logging intervals) With Daily Update
• Sensors: By Onset Computer -Generated Power in kWh, Solar Radiation and Ambient Temperature

Both the crystalline and thin film photovoltaic arrays are each independently grid interconnected through an SMA Sunny Boy Inverter, for balanced inverter loading. As noted in the test bed configuration section, the amorphous thin film photovoltaic system has a 96 watt DC size advantage over the crystalline photovoltaic system, due to module wattage differences and string sizing requirements.

The Photovoltaic Test Array Data Logger
The performance and kWh output data of the photovoltaic test array is recorded by an Onset Computers HOBO U30-WIF cellular remote data logger. Sensors provided by Onset Computers measure Generated Power Output in kWh for both the crystalline and thin film photovoltaic arrays, as well as Solar Radiation and Ambient Temperature. The HOBO U30-WIF records the data in fifteen minute intervals and uploads the compiled information log to the test array website on a daily basis, where it can be viewed and downloaded by our potential customers.

The data logger is housed inside a weathertight enclosure and secured with a padlock to keep people from meddling with the device settings. The data logger has an onboard battery that is powered by an independent photovoltaic module mounted six feet above the data logger, with a clear view of the sun. The Solar Radiation sensor is mounted adjacent to the data logger photovoltaic module in a place where they will not shade each other. By having an onboard, independent power source, as well as its own cellular remote communication ability, the HOBO U30-WIF is able to independently operate and communicate, regardless of availability of grid power.

The output and performance data compiled by the HOBO data logger is uploaded to a server administered by Onset Computers, located in Bourne Massachusetts on a daily basis. This assures the integrity of the data, as our personnel and others do not have access to the information sent to the server, and thus cannot manipulate or affect the results.

The Output And Performance Data
The output and performance data compiled from the crystalline and thin film photovoltaic arrays is available in Excel format on the test array website. We encourage you to review and use the data to help in your determination of which photovoltaic system type you might want installed on your residence or business. Please keep in mind that the test array website, data that is produced by the test array and the Excel data logs maintained on the website are property of Beachside Solar Technologies. Please do not sell or include the data available on this website with other studies or reports without express written consent from us. Feel free to contact us with any requests of this nature.

Click Here For Live Statistics from the Beachside Solar Big Island Test Array

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