An electricity grid is a certain area where one or more generators provide the demanded power.

This can be limited to a little company, a nation or a continent like Western Europe.

“Standalone” only means that this grid is autarky and independent from other grids.

The grid itself has to control, regulate and “match” generation and consumption of electricity at the same time.

The larger the grid the less fluctuations you have to compensate and the more stable the grid works.

“Gridparallel” means that you work together with another, normally with your national “mother” grid. In this case you depend on the quality of your “mother” grid.

In Nigeria the power demand is much bigger than the supply. Therefore whenever the grid management cannot match the increasing consumption any more by increasing generator power they have to cutoff consumers from the grid causing blackouts only for these customers.

This allows the national grid to stay stable with bad luck for the dark areas.