What it takes to be a Solar Technologist?By Rinn Teo
December 15, 2020
Have you ever wondered what it feels like to install solar panels on the roofs of HDBs/buildings and what does it look or sound like to be on a roof top with solar PV panels and inverters?
In conjunction with our recent recruitment "Be A Sustainability Hero", where we are on the lookout for likeminded peeps to join us as either Solar Technologist, we have dedicated this entire blog to what it takes to be Solar Technologist. And for this blog, we followed our Project Engineer, Mr. Lutfi, when he was tasked to install panels onto a site. We also asked him some of the common Frequently Asked Questions (FAQs) he received while doing the installation, which will be revealed at the end of this blog post.
STEP ONE: HOISTING OF MATERIALS TO THE ROOFBefore hoisting, or simply put, lifting operation, our technicians will erect barricades and nettings surrounding the perimeter of the block and on the roof so as to prevent passersby from getting injured.
What happens on the ground:
1. Mobile crane arrives
This pole you see is called an outrigger, and it extends out of the mobile crane on all 4 sides.
2. Stabilize the footing of the 4 outriggers
3. Open the jig to test the height from the ground to the roof level for hoisting
4. Once everything has been prepared properly, the first lifting will commence
5. Stone slabs and solar panels will be lifted up to the roof for installation
STEP TWO: SOLAR PV (PHOTOVOLTAIC) PANELS INSTALLATIONWhat happens on the roof:
1. Spread out the hoisted materials (stone slabs and solar panels) evenly to prevent placing heavy pressure on a single load point
2. Place the stone slabs in position
3. Inserting structure frames on the stone slabs
4. Mounting solar panels on the structure frames according to the layout drawing
5. Stringing of all the solar panels in a series according to the string configuration drawing
STEP THREE: INVERTER INSTALLATION AND CONNECTION:
1. Stringing of DC (direct current) cable trunking to inverter (solar inverter: DC converts to AC (alternate current)) according to string configuration layout
2. Mounting of AC panel and inverters
STEP FOUR: CONNECTIING THE INVERTER TO THE SWITCH ROOM
1. Running of AC cables from AC panel (roof) to Switch Room (ground level)
2. Termination of AC cables to modified MSB (main switch board) panel inside switch room
3. Arranging shutdown of electricity for connection and energizing of the newly installed system
4. Pre-commissioning checks by Sunseap
STEP FIVE: COMMISSIONING OF SOLAR PV SYSTEM
Testing and commissioning of the solar system
Now that we know what it takes to install a Solar PV System on a HDB roof, what kind of questions do you think Lutfi gets from the HDB residents when he does his installation? You'd be amazed at some of the questions that gets thrown at him:
Q: Since you are doing solar panel installation, can I buy some solar panels from you? I only need 1 or 2 mini ones to put at my kitchen window for some extra electricity.
A: ...Don't you know that your window panels are made of solar panel materials as well, allowing it to absorb electricity? (sarcasm; but we don't do this all the time)
Q: Solar installation? So… electricity? Can you help me fix my water heater too? You're HDB-hired, right?
A: No, I'm unable to fix water heaters. No, I'm not HDB-hired. Sorry, I have to get back to work. (I can't be too rude, even if the question is… the way this is, so as not to tarnish our reputation/appearance)
Q: You don't look busy, carry these bags of groceries for me up the stairs to my house on the 3rd floor. The lift shutdown is your fault anyway.
A: ...Sure. (during the shutdown of electricity listed above in step 4-3, the lift will not be operatable, and all the more to help if the resident is an elderly)
My thoughts after following Lutfi for a day at the site:
What was most exciting for me during my site visit was how to get up on the roof, and actually standing on the rooftop. Ordinary people like me would have never had the chance to experience that. The wind was as cooling as I imagined, and the sky looked so close to me. Of course, standing on the rooftop means I have to undergo safety precautions set by the Safety Supervisor. And the steps listed above will all undergo in a span of 2-3 weeks before the solar panel system can be successfully utilized.
All in all, it was a fun experience for me, and I hope it will be for you too. Being there, I experienced the warmness between the staffs and the trust they have in each other. I could also see how deep their friendship went. Thus, I believe this job provides not just career advancement, but also a lifelong friendship and experience. 😄