  Electrical grids are geographical and topological structures whose voltage
states are challenging to represent accurately and efficiently for visual
analysis. The current common practice is to use colored contour maps, yet these
can misrepresent the data. We examine the suitability of four alternative
visualization methods for depicting voltage data in a geographically dense
distribution system -- Voronoi polygons, H3 tessellations, S2 tessellations,
and a network-weighted contour map. We find that Voronoi tessellations and
network-weighted contour maps more accurately represent the statistical
distribution of the data than regular contour maps.
