This is a huge area that takes a lot of development. When you talk about electricity network, are you talking about just putting points to represent power stations, substations, etc, or are you talking about representing the actual cabling as well.
Is this going to be a commercial solution? Do you have access to mapping?
GIS systems tend to be hugely expensive because the underlying GIS engine is expensive, and the mapping costs a lot (plus it has to be kept up to date so you have to consider how you will roll out mapping updates). If you go with a solution like Google or Bing maps, there's a relatively light development cost, but a very expensive solution cost. Alternatively you could use a library like dotspatial
] which is free.
There are many, many things to consider when developing a GIS solution. What experience do you have with GIS?