SHeat m,d,h
Amount of stored heat available at the start of hour h, day d, month
m (kW)
OElec m,d,h,u
Amount of stored electricity that is released to meet the load of end
use u during hour h, day d, and month m (kW)
SElec m,d,h
Amount of stored electricity available at the beginning of hour h,
day d, and month m (kW)
Flag O,m,d,h
Indicator variable for discharge of electricity from the electricity
storage unit
Flag I,m,d,h
Indicator variable for charge of electricity to the electricity storage
unit
D i,m,d,h
Indicator variable for the state of equipment operation
Pf p,q
Indicator variable for the existence of pipeline
H p,q,m,d,h
Heat flow between sites
Esal i,m,d,h
Electricity sold to the gird from technology i, in hour h, day d, and
month m (kWh)
6.1 General Structure of the Tool
The tool to optimize the integration of a distributed energy system is formulated as a
mixed integer linear programming (MILP) model. The use of integers represents, for
example, the number of pieces of equipment adopted. Figure 6.1 is a flowchart
illustrating the model structure. The objective function to be minimized is the annual
cost of providing energy services to a site, through either utility electricity and gas
Building information
or energy unit
Gas and electric
power companies
DER technologies and
absorption chiller
manufacturers
Market investigation
Government and
administration
Energy demands of
-users (electricity,
cooling, heating,
hot water)
Gas and electricity
tariff for the user
Economic information
(interest rate and
cost data)
Policy, subsidies
DER and absorption
chiller technical
characteristics
MILP Model
Min=Cost
Energy balance
Equipment constraint
Optimal
equipment
capacity
Environmental
and energetic
assessment
Optimal
technology
combination
Optimal
running
schedule
Economic
assessment
Fig. 6.1 Flow chart of model for distributed energy system optimization
6 Development of a Tool to Optimize Urban-Rural Linkage and a Decentralized Power. . . 123
Amount of stored heat available at the start of hour h, day d, month
m (kW)
OElec m,d,h,u
Amount of stored electricity that is released to meet the load of end
use u during hour h, day d, and month m (kW)
SElec m,d,h
Amount of stored electricity available at the beginning of hour h,
day d, and month m (kW)
Flag O,m,d,h
Indicator variable for discharge of electricity from the electricity
storage unit
Flag I,m,d,h
Indicator variable for charge of electricity to the electricity storage
unit
D i,m,d,h
Indicator variable for the state of equipment operation
Pf p,q
Indicator variable for the existence of pipeline
H p,q,m,d,h
Heat flow between sites
Esal i,m,d,h
Electricity sold to the gird from technology i, in hour h, day d, and
month m (kWh)
6.1 General Structure of the Tool
The tool to optimize the integration of a distributed energy system is formulated as a
mixed integer linear programming (MILP) model. The use of integers represents, for
example, the number of pieces of equipment adopted. Figure 6.1 is a flowchart
illustrating the model structure. The objective function to be minimized is the annual
cost of providing energy services to a site, through either utility electricity and gas
Building information
or energy unit
Gas and electric
power companies
DER technologies and
absorption chiller
manufacturers
Market investigation
Government and
administration
Energy demands of
-users (electricity,
cooling, heating,
hot water)
Gas and electricity
tariff for the user
Economic information
(interest rate and
cost data)
Policy, subsidies
DER and absorption
chiller technical
characteristics
MILP Model
Min=Cost
Energy balance
Equipment constraint
Optimal
equipment
capacity
Environmental
and energetic
assessment
Optimal
technology
combination
Optimal
running
schedule
Economic
assessment
Fig. 6.1 Flow chart of model for distributed energy system optimization
6 Development of a Tool to Optimize Urban-Rural Linkage and a Decentralized Power. . . 123