model and optimisation

Where the next hubs go

Capacitated maximal covering MILP: 4 x 150 kW hubs, 8-minute drive-time coverage, Erlang C capacity and a substation headroom filter. One plan is solved for each of P10, P50 and P90 demand and tested under the others. The recommended plan has the smallest worst-case regret.

Unmet rapid demand, sessions per day

under 0.1
0.1 to 0.3
0.3 to 0.5
0.5 to 0.9
0.9 to 1.7
1.7 and over

4 x 150 kW hubs

robust core: all three plans agree
outside the core