Flexible vs Rigid Solar Panels for DIY Projects in the Philippines

For most Philippine DIY projects, choose a rigid glass panel for a fixed spot you can mount properly (a roof, a carport, a steel frame), and a flexible panel when weight, a curved surface or portability matters more than long life and cooling. Among the panels we track, only the PowMr 100W flexible panel and PowMr 150W flexible panel have full manufacturer electrical specs (both Voc 21.6V, Vmp 18V). For the PowMr rigid panels, the PowMr 200W flexible, Flowatt and Bosca panels, the key numbers are either missing or come only from the shop listing, so you must read the label before wiring.

That last point matters more than the flexible-or-rigid choice. A panel’s open-circuit voltage (Voc) and short-circuit current (Isc) decide what you can safely plug it into. If you don’t know them, you can’t check a power station’s input limit or a charge controller’s maximum. This guide explains the real differences between the two panel types, goes through what each listing does and doesn’t tell you, and covers heat, typhoon wind and mounting in plain terms.

The short version: which type fits which job

Neither type is “better” in general. They solve different problems.

What actually differs between flexible and rigid panels

Construction

A rigid panel has solar cells sealed behind tempered glass, held in an aluminium frame, with a junction box on the back. The frame is what you clamp to a rail. The PowMr and Flowatt rigid listings describe this kind of panel (“rigid tempered glass”).

A flexible panel has the cells laminated in thin plastic layers, with no glass and no frame. It bends a little to follow a curved surface. It is mounted by its corner holes, by adhesive, or by ties, depending on the maker’s instructions.

Weight and handling

Rigid panels are heavy. The listings give:

• PowMr 100W rigid: 875 × 645 × 25mm, 5.55kg
• PowMr 200W rigid: 1340 × 765 × 30mm, 9.65kg
• Flowatt 200W rigid: 1340 × 765 × 30mm, 9.65kg

PowMr does not publish the weight or size of its flexible panels, so we can’t give you a like-for-like comparison in kilos. Flexible panels are generally much lighter because they have no glass or frame, which is the main reason people buy them. Check the listing photos or ask the seller for the exact size before you plan where it goes.

Durability

Glass and an aluminium frame protect the cells from hail, falling branches and foot traffic during cleaning. A flexible panel’s plastic surface is easier to scratch and the cells inside can crack if the panel is bent too far or stepped on. Neither PowMr nor Flowatt publishes a minimum bend radius for these listings, so bend only as much as needed and follow the instructions in the box.

Junction boxes and weather

PowMr’s flexible panels have IP65 junction boxes. The PowMr 100W and 200W rigid listings and the Flowatt 200W rigid listing say IP67 junction boxes. Both ratings are about dust and water entering the junction box, not the whole panel. Keep connectors off the roof surface where water pools, and point the cable entry downward where you can.

Verified specs: the PowMr 100W and 150W flexible panels

These two are the only panels in this guide where the electrical figures come from the manufacturer’s own page.

Two things to note:

1. The 150W listing shows different numbers from PowMr’s own page. The Lazada variant label has a voltage, current and efficiency that don’t match PowMr’s spec table (and its voltage times current doesn’t even come to 150W). Go by PowMr’s figures above and the sticker on the panel you receive.
2. The connector type isn’t published. Check the photos or ask the seller whether it ends in MC4 plugs. If it doesn’t, you’ll need the right adapter for whatever you plug it into.

Both panels are “12V-class” panels: an 18V operating voltage, suitable for charging a 12V battery through a controller or for the 12–28V solar input of small power stations. If you want to run one on a BLUETTI Elite 30 V2, our Elite 30 V2 solar kit guide covers what fits that input, including these two panels.

What the other listings do and don’t tell you

This is where buyers get caught. Below is what is known for each panel we link to, and what is missing.

PowMr 100W rigid: listing-only, no Voc or Isc

The PowMr 100W rigid panel is not on PowMr’s own store. The Lazada listing gives 100W, “21.7V” in the title (with no label saying what that voltage is), MC4-compatible connectors, a 1.5mm² cable 900mm long, the size and weight above, and an IP67 junction box. No Voc, Isc, Vmp or Imp is published anywhere we could find.

The listing also says it has 32 pieces of 210mm cells, which can’t physically fit in an 875 × 645mm panel unless they are cut cells. That kind of loose wording is a reason to check the real label.

PowMr 200W rigid and Flowatt 200W rigid: listing-only, probably the same panel

The PowMr 200W rigid panel and the Flowatt 200W rigid panel have identical listings: 200W, “19.4V” in the title (unlabelled), 56 cells, MC4-compatible connectors, 2.5mm² cable 1000mm long, 1340 × 765 × 30mm, 9.65kg and an IP67 junction box. Neither gives an electrical table. They may be the same panel under two names, but that isn’t confirmed.

PowMr 200W flexible: no longer on PowMr’s site

The PowMr 200W flexible panel (also on Lazada) is no longer in PowMr’s online catalogue. Its old page now shows the 150W panel. The listing variant says “200W 25.2V 10.28A” without saying which voltage and current those are. They may be Voc and Isc, but that isn’t verified, so we don’t use them for any wiring decision. The Shopee link goes to PowMr’s official Shopee store.

Flowatt 120W flexible: almost nothing published

The Flowatt 120W flexible panel listing gives “120W 21.6V” in its model field and nothing else electrical: no labelled Voc, no current, no connector type, no size or weight. We found no official Flowatt website or datasheet.

Bosca 60W, 120W and 160W: listing figures that look like a template

The Bosca listings do give full-looking tables:

But we found no official Bosca datasheet. Every size has exactly the same Voc and Vmp, and each Imp is exactly the wattage divided by 18. Real panels of different sizes rarely line up that neatly, so these look like a template rather than measured data. The connector isn’t stated either, so the panel may come with a bare junction box rather than MC4 plugs. Treat all Bosca numbers as seller claims and confirm them against the label.

Summary of what’s verified

What “check the label before wiring” means in practice

Every proper solar panel has a sticker or plate on the back with its rated figures, measured at standard test conditions. When your panel arrives:

1. Photograph the label before you mount the panel. Once it’s on the roof, you won’t be able to read it.
2. Write down four numbers: Voc (open-circuit voltage), Isc (short-circuit current), Vmp (voltage at maximum power) and Imp (current at maximum power).
3. Compare Voc with the input limit of whatever you’re connecting to. A power station or controller manual gives a maximum input voltage. The panel’s Voc (or the total Voc of panels in series) must be below it, and we recommend keeping at least a 10% margin.
4. Compare Isc with the input current limit, where the device publishes one. Some small power stations have a strict current limit, and a panel that’s slightly over can be a problem.
5. Check the connector. MC4 is the common standard on rigid panels. Small portable panels may use DC5521, XT60 or other plugs. You need the right cable.
6. If the label is missing or unreadable, don’t guess. Ask the seller in writing for the spec sheet. If they can’t give one, return the panel.

A cheap multimeter set to DC volts lets you measure Voc on a sunny day (panel disconnected, probes on the two terminals). It’s a useful sanity check against the label, but it is not a substitute for the label, because Voc changes with temperature and sunlight.

Heat: why mounting style matters in the Philippine sun

Solar cells produce less power as they get hotter. In a Philippine summer, a panel’s surface can get much hotter than the air around it. How much power you lose depends on the panel’s temperature coefficient, which none of the panels in this guide publish. So we can’t give you a percentage, only the general rule: keep air moving behind the panel.

• Rigid panels on rails sit above the roof with a gap underneath. Air flows behind them and carries heat away.
• Flexible panels glued or taped flat onto a metal roof have no gap. The panel and the hot roof heat each other. Expect lower output in the middle of the day than the same panel would give with air behind it.
• Flexible panels on a light frame or tied over a gap do better than ones stuck flat.

If you use a flexible panel on a vehicle or a boat, it will often be flat against the roof anyway. That’s an accepted trade-off for the low weight and low wind profile. Just don’t expect it to match the label wattage on a hot afternoon.

Typhoon wind: the biggest risk is a panel coming loose

A solar panel is a flat sheet that catches wind like a sail. In a typhoon, the danger is less about the panel breaking and more about it tearing free and becoming a flying object, or ripping the roof sheet it’s fixed to.

General points for each type:

• Rigid panels should be fixed with proper clamps to rails, and the rails fixed into the roof’s purlins or rafters, not just the thin roof sheet. Our metal roof mounting guide goes through rails, end clamps, mid clamps and sealing in detail.
• Flexible panels stuck on with adhesive depend entirely on that bond. Heat, UV and time can weaken it. If a corner starts lifting, wind can peel the whole panel off. Check the edges after every storm.
• Portable and folding panels should simply be brought inside when PAGASA raises a wind signal. They aren’t designed to stay out in a storm.
• Cables should be clipped down so they don’t flap and wear through.

We don’t quote wind-speed ratings here because none of these listings publish them. If your panel will stay on a roof through typhoon season, have the mounting checked by someone qualified. A structural or civil engineer can tell you whether your roof framing is up to it.

Mounting options for each type

Rigid panels:

• Rails plus end clamps and mid clamps on a metal roof. A solar rail and clamp kit for metal roofs is the usual starting point. Match the clamp height to your panel’s frame thickness: the PowMr and Flowatt 200W rigid panels are 30mm thick, which suits 30mm end clamps; the PowMr 100W rigid is 25mm and the Bosca 120W and 160W are 35mm, so they need clamps sized for those frames.
• Z-brackets for a single small panel on a flat surface, wall or frame.
• A steel or aluminium frame on the ground or on a concrete roof deck, with the panels bolted to it.

Flexible panels:

• Screws or bolts through the corner grommets onto a flat board or frame.
• Adhesive or tape where the maker allows it (check the instructions; some makers specifically recommend against certain adhesives).
• Cable ties to a frame for temporary use.

Either way, a solar panel angle guide helps you check the tilt once the panel is up. Some tilt also helps rainwater wash dust off.

Safety and who does what

A portable panel plugged into a power station is a plug-and-play setup you can do yourself by following the manual. Anything wired to the house, a breaker panel, the roof structure or the grid needs a licensed electrician working under a Professional Electrical Engineer’s plans, plus an LGU electrical permit. Under RA 7920 Sec. 34, electrical installations must follow the Philippine Electrical Code and be done under the supervision of a professional electrical engineer, registered electrical engineer or registered master electrician. If you ever want to export power to the grid, that goes through your electric company’s process; see our net metering guide.

For working out how many panels you need in the first place, see how many solar panels a Philippine home needs or try the solar system size calculator. For a bigger rooftop project, read the residential solar installation guide.

What to buy

Flexible panels with verified specs (best choice if you need flexible):

• PowMr 100W flexible panel on Lazada: Voc 21.6V, Isc 6.11A. Confirm the connector type with the seller.
• PowMr 150W flexible panel on Lazada: Voc 21.6V, Isc 9.16A. Ignore the listing’s variant label numbers; use PowMr’s.

Rigid panels (check the label before wiring):

• PowMr 100W rigid panel on Lazada: ask the seller for Voc and Isc before buying.
• PowMr 200W rigid panel on Lazada or Flowatt 200W rigid panel on Lazada: same listed size and weight; ask for the electrical table.
• Bosca 60W, Bosca 120W or Bosca 160W on Lazada: listing figures only; confirm the label and ask what connector it has.

Flexible panels with unverified specs:

• PowMr 200W flexible on Shopee (PowMr Official Store) or on Lazada: the “25.2V 10.28A” figures are unlabelled; confirm Voc and Isc.
• Flowatt 120W flexible on Lazada: no electrical table at all; only buy if the seller sends one.

Mounting:

• Solar rail and clamp kit on Shopee or on Lazada
• 30mm end clamps on Shopee (for 30mm frames only)
• Z-brackets (4 pcs) on Shopee
• Solar panel angle guide on Shopee

Prices change daily, so check today’s price on each listing.

Bottom line

Pick rigid for anything permanent and roof-mounted, and flexible for light, curved or portable jobs. Whichever you choose, the deciding factor is whether you know the panel’s real Voc and Isc. Right now, the PowMr 100W and 150W flexible panels are the only ones in this group with manufacturer-published electrical specs. For every other panel here, photograph the label, write down the four key numbers, and don’t connect anything until they check out.