What’s the point of inverters in Solar PV systems at home if DC is used?

Question

So solar panels produce DC current, no conversion actually happens when sunlight is generated as electricity.

The DC current is then converted to AC as it is efficient in the electrical grid for long distances. However it is also used at home and majority of devices (hardly at least) don’t use AC as it gets converted to a safer DC current. This is especially important for electronics and battery recharging. When conversion happens, majority of that energy is lost as heat which you would find in the charging brick. In addition, with smartphones and EVs, wouldn’t direct DC be more efficient and quicker to charge than converting it back to DC. [Proponents claim that it would be beneficial if buildings had a ‘AC-DC converter box’ near a switchboard.](https://www.youtube.com/watch?v=hF_A4sp7nM8) (should mention that this is not a very credible source but others also claim similar stuff with DC)

So as I said before, why is AC forced as the current for homes instead of direct DC. Only current that needs to be exported to the grid would benefit from AC conversion. I couldn’t really see any answer to this with solar on mind. They will say AC is used for powering things while the other sites claim that AC burn devices if used.

In: 13

Answer 1

The DC voltage from panels varies widely. Often installations have multiple strings of panels feeding the same inverter and each strip can have a different number of panels facing in different directions and so having different voltages. You need a device like an inverter to get a single usable output standard. Otherwise you have to design a complex power supply into every electrical device in the house.

So given you need a device between the panels and the house circuits, it may as well output the same AC standard power we’ve been using for decades. Conversion these days is very efficient and any difference between outputting AC vs DC is going to be negligible. And who wants to throw away all their existing AC appliances to attempt to replace them with new DC ones of which there’ll be, at best, a very limited selection.

Also, switching high power DC can be a problem because it’s never at zero. You can get sustained arcing at the switches when you turn them off. With AC the arc stops quickly as the voltage crosses through zero. If you have an inverter, turn off the AC isolation switch first before the DC.