Project Site Plan
The shape in red is the exact location of the project.We will be installing our panels on this 3.9 hectare of land in Seraya Place, Jurong Island. As indicated in the site plan below, we will be doing on Lot 3455WPT.
The image shown below is the Topographical Soil Investigation and Cable Detection Survey which was carried out at Jurong Island. This is to inspect the soil condition before we proceed with the installation.
Solar Panels Layout
As stated in the diagram, the total number of panels that we will be using are 15, 654. The direction of the panels is South and the inclination of panels is 10 degree. There will be 15 sets of 80 x 10 panels (10 rows of 80 panels), 3 sets of 40 x 10 panels (10 rows of 40 panels), 4 sets of 80 x 2 panels (2 rows of 80 panels), 1 set of 40 x 2 (2 rows of 40 panels), 1 set of 80 x 3 (3 rows of 80 panels).
The diagram below shows the array layout for one solar panel; the dimension and the view of panels at 10 degree from top view. The top view of the panels is the 20 x 2 panels, where it shows the view of 2 rows of 20 panels.
Singapore Sun Path, Angle and Solar Radiation Data
To calculate the optimum orientation and tilt for the solar panel, local Sun Angle and Sun Path data is needed. Solar Time for which the plant will perform with its maximum efficiency can be calculated from the sunrise and sunset timing data.
Image source: SERIS http://www.solar-repository.sg/irr-map.cfm
Solar Irradiance and Surface Meteorology Data for Site
Inter-row Spacing and Layout of Panels
The procedure for calculating shadow spacing starts with the sun’s position in the sky on a winter solstice, December 21st. You need to obtain the minimum solar altitude angle α, which is the minimum angle the sun makes with the ground in your shade-free solar window (Figure 1). For a 4 hour solar window, you want to obtain the sun’s altitude angle at 10 AM or 2 PM on December 21st, as that is when the sun will be the lowest in the sky. For a 5 hour solar window, you will need the sun’s altitude at 9:30 AM or 2:30 PM instead. When you find this angle, you will most likely also be able to get the sun’s azimuth angle, ψ. This is how far off true south the sun’s position is (Figure 2), and will be needed to obtain the minimum allowable row spacing.
Figure 1, Image source : Affordable Solar Wholesale Distribution http://www.affordable-solar.com/learning-center/building-a-system/calculating-tilted-array-spacing/
Figure 2, Image source : Affordable Solar Wholesale Distribution http://www.affordable-solar.com/learning-center/building-a-system/calculating-tilted-array-spacing/
After finding the Solar Altitude and Azimuth angles, the calculations to determine row spacing can begin. For most ground and roof mounted systems where row spacing is a concern, the height (h) of the obstruction can be directly obtained from the dimensions of the solar panel and the array tilt. Alternately, it can be measured as the difference in height between the bottom/leading edge of one row and the maximum height of the next row South of it, or a direct measurement of whatever obstruction you want the array to avoid (Figure 1). Using this height, the maximum shadow distance can be obtained. The shadow distance is found through using simple trigonometry.
Substation Design and Layout
SP group will lay 2 nos. 22 kV feeders to the solar farm and these 2 feeders will terminate in SP’s 22 kV switchgear and they will require a 22kV substation complying with the requirements to be built to house these switchgears. The dimensions of the substation will be the standard 22kV substation, i.e. 6m (L) x 6.2m (D) x 5.6m (H). We will bulid a 22 kV next to SP’s 22 kV substation for connection of the power from the solar farm to their network.
SP group will install 2 nos. bi-directional kWh meters in our 22 kV switchgear to record both export and import of the electricity to and from the grid. Power quality and Protection specifications which will maintain to meet Singapore’s standard are mentioned in Figure 3.
We would use Radiant mounting system due to the fact that Radiant mounting system is like building a “Lego” solar system. This is because Radiant mounting system was designed in the first place to reduce installation time in OECD countries where labour cost is the highest component cost besides the solar module.
Radiant mounting system can achieve this because all of the connecting clamps, and also joiner parts does not involve any screw system and it utilises “click & lock” where the mid & end clamps and also other joiner parts are designed to click and lock in place without requiring any screw. In our Australian rooftop system, Radiant is proved to reduce installation time between 25% to 50%.
By using this system, we will be reducing our installation time as this is a ground mounted project. Additionally, we also believe that the time required to remove the systems will also be reduced significantly. We are quite confident to state that we will be able to commit to the removal time frame of less than 6 months for the entire site.