when building a solar panel should the diode be on the positive or negative sidelittle more detail i just built a solar panel and im running it to a grid tie converter should i put diodes in if i add another panel or are they only for battery systems?
I'm assuming you're talking about the blocking diode and not the bypass diodes. Positive side.
the blocking diode goes on the positive side
Bypass diodes would be in parallel with groups of solar cells in a panel. For example, if a module has 72 cells, maybe every 8 cells, there will be a bypass diode. A bypass diode does nothing except salvage some of the energy from the panel if some of the cells are shaded, and others are not. Or, if you have multiple panels in a series string, the bypass diodes allow the other panels in a string to continue to contribute energy when one panel is shaded. Unless you're forced to put the panel(s) where there will be shade during the day, the bypass diode does not matter. Commercial panels all include bypass diodes. Blocking diodes are generally NOT included on commercial panels. If you're going to a grid-tied inverter, you probably don't need one. There are stringent regulations on how panels must be grounded, and whichever side of the panel is grounded should not have a blocking diode. NEC regulations call for a continuous ground to earth. For example, if you have negative ground on your system, the blocking diodes, if any, should go on the positive terminal of the panel. By the way, if you're in the US or Canada, do understand that a home-built panel will not be legal to connect to a grid-tied system. And a grid-tied inverter that plugs into the wall will also be illegal. I'm only saying this because I don't want you to get hurt, or your house to burn down. Line power is nothing to be trifled with.
