The closest question to this is Linear useage of excess power generation.

I'm no engineer so I may not be able to phrase this correctly and would appreciate an answer which assumes minimal background knowledge (I have only a basic understanding of voltage, transformers, etc). The question arises from all this talk of the variable wind and power potentially disrupting the grid.

For example see the 2012 Electrical Connection article Rapid increase in solar installations potentially overloading the grid which discusses the potential for "reverse power flow" and also talks about some sort of "network protector" device. Also there is a or similar article about Hawaii The Interconnection Nightmare in Hawaii and Why It Matters to the US Residential PV Industry , which says the only "concrete concern identified by the Hawaii experience is the potential for transient overvoltage on the feeder – essentially a short duration voltage spike".

I'm curious about what happens here both with regard to a large grid and in a micro environment. For example, let's say I have a fully charged battery and I keep flowing electricity into it. What happens? Are there devices which will divert or dissipate the electricity as heat without damaging anything? I found a few similar questions online but the answers weren't too clear.