Table 1 List of symbols

$\mathit{j }\left[\begin{array}{c}dg\\ pv\\ w\\ bc\\ bd\end{array}\right]$

Dieselgenerator

Photovoltaic

Wind turbine

Battery charging

Battery discharging

   η _j

Efficiency of technology j

   S_g,t

Global horizontal radiation at time segment t

   cc _j

Annualised specific first cost of technology j

   P_e,off P_e,on

Off-grid and on-grid electricity price

   c _j

Capacity of technology j

   n_inv

Efficiency of inverter

   FLH

Annual full-load hours of PV

   mc _j

Specific maintenance cost of technology j

   TPC

Total annual power consumption

   x _j,t

Usage of technology j at time segment t

   tc

Total annual cost of energy system

   v_w

Wind velocity

   p_d

Diesel price

   CGE

Specific cost of grid extension to national power line

   cf _j,t

Capacity factor of technology j at time segment t

   bs _t

Battery charging status at time segment t

   d

Break-even distance to national grid