Yes it should be possible. Thata what id called as optimisation

Optimal depends on definition considering cost of installation, cost of distribution losses , cost of energy source feed and sometimes more importantly socioeconomic and political loses locating in a sensitive area. 

e.g. Ontario fiasco of Gas TUrbine Power location setup cancelled at major cost to taxpayers after regional disputes.

Yes you can find it. But the difficulty of solution process depends on which optimization method you are using. If you plan to use conventional methods like NR and Interior point algorithms .... then you have to derive all the complicated first and second order derivatives and then frame the optimality conditions...... If you want to use meta-heuristic optimization, things become bit easier ... use any of the already developed NR power flow code with voltage dependent loads as underlying objective function (with some post processing of the results).....