Solar Panels

Solar panels for off grid, marine and vehicle systems. Four framed panels from 70W to 410W, and two flexible panels that are light and can bend.

The rigid panels are PERC monocrystalline behind 3.2 mm high transparency glass with an anti reflective self cleaning coating, in an anodised aluminium frame, with an IP65 junction box and MC4 leads already fitted. 120W, 220W and 410W in the usual rectangle, and a long thin 70W at 1134 x 300 mm designed to fit into narrow gaps. All four are rated -40 to +85°C and carry a 25 year warranty. The 410W is a half cell panel, so shade across one half does not drag the whole panel down.

The two flexible panels are Sunpower monocrystalline back contact cells, 3 mm thick, 0.7 kg for the 50W and 1.2 kg for the 90W against 9 kg for a framed 120W. They bend to 30 degrees, the junction box is on the front so the panel lies truly flat, there are 6 mm eyelets in the corners, and they are UV protected for continuous exposure to marine elements. Buy one because the shape or the weight rules out a framed panel.

Sizing starts with what you use, not with the roof. Work out the amp hours you take out of the battery in a day and put back more than that each day, because a panel only makes its rated output in full sun square on to it.

Every panel’s open circuit voltage is in its spec table, and that is the number to add up for a series string, not the working voltage. As a system these are rated to be connected in strings at up to 1000V DC, except the 70W which is 500V DC and the flexibles at 600V DC, but the ceiling that matters is the charge controller’s and it is far lower.

A fuse on every string of PV panels is now required, and each panel’s maximum series fuse rating is in its spec table, 10A to 20A across the range. The fuses, the MC4 connectors and the DC isolator are in Solar Connectors. Rails, clamps and tilt legs are in Roof Mounting, and the clamps are sized on the thickness of the panel frame rather than on the wattage, so check the frame thickness before you order. Cable, the earth kit and the crimping gear are in Solar Cabling.

If you are not sure, tell us your battery voltage and what you take out of it in a day, and we will tell you what fits.