Japan Solar Energy Soars, But Grid Needs to Catch Up

[Yo_Mama]

2. Japan already has a lot of pumped storage plants. About 25% of world capacity

The problem is going to be getting power from Hokkaido to those plants.

Japan is unique among developed nations in that it has a split grid. The northern grid runs at 50 herz and the southern at 60 herz.


There are a few frequency conversion points that can pass voltage between the two systems, but it's low capacity. There is also poor interconnectivity between the utility regions, which further complicates matters.

So as it currently goes, just about none of the power can be passed down to the south.


The reason Japan has so much pumped storage is that it always ran its power plants so as to maximize their efficiency, and pumped storage was created to take the overflow and redispatch it during peak periods. So in some ways Japan is almost uniquely "ready" for renewables.

However they are going to have to change the grid quite a bit to pass that power around where it is needed.

Older IEEE article with more detail:
http://spectrum.ieee.org/energy/the-smarter-grid/why-japans-fragmented-grid-cant-cope

Pumped hydro:
http://people.duke.edu/~cy42/PHS.pdf