History of engineering & technology PPA bidding formats copula day-ahead electricity markets distributed solar PV earnings electricity market electricity markets electricity price forecasting energy trading entropy equilibrium analysis expansion planning feasible operation financial analysis fundamental-econometric models game theory-Cournot model gas markets industrial park integrated energy system information theory investor-owned utility market design market structural breaks medium-term representation min–max regret value natural gas price uncertainty natural-gas market net-energy metering optimization models