Risk-Constraint Scheduling of Storage and Renewable Energy Integrated Energy Hubs

Abstract

An energy hub has been lately introduced as a powerful model to optimize the cooperation among variety forms of energy. The energy hub provides output demands through converting, transmitting or storage process, feeding by various kinds of energy fuels as inputs of generating infrastructures. Input and output consist of different kinds of energy such as heat, power, gas, and hydrogen to promise the diversity of consumption side. In response to environmental concerns and increasing energy needs, the trend toward renewable distribution energy resources has been increased. In this chapter, the authors consider a renewable-based energy hub which contains wind turbine (WT), photovoltaic (PV) cells, energy storages, boiler, etc. Volatile nature of renewable energy resources makes new challenges to supply the demands. In this regard, an optimal stochastic short-term scheduling, considering the uncertainties of the renewable generations is presented. The stochastic formulation is led to design of optimal planning to increase not only total profit but also consumers’ satisfaction. A scenario-based technique is utilized to evaluate the uncertainties of the renewable sources. In order to decrease the number of sceneries, a proper scenario reduction method is applied on the problem. The influence of uncertainty factors such as solar irradiation and wind speed is investigated in the problem formulation. Moreover, in the scheduling model risk management problem is also considered. To confirm the effectiveness of the proposed method, it is applied on a proper test system.

Nomenclature

10.1.1 Indices

ω :

Scenario index [1 : N _ω ]

e :

Index of electrical storage unit

h :

Index of thermal storage unit

s :

Index of energy storage units

t :

Time index [1 : N _t ]

10.1.2 Parameters

α :

Confidence level

${\eta}_h^B$ :

The efficiency of boiler unit

${\eta}_e^{\mathrm{CHP}}/{\eta}_h^{\mathrm{CHP}}$ :

The efficiency of electrical/thermal generation of CHP unit

η ^PV :

The efficiency of PV panel

${\lambda}_t^e/{\lambda}_t^g$ :

Electricity/gas price of the grid at tth hour

${E}_{\mathrm{min}}^s/{E}_{\mathrm{max}}^s$ :

Minimum/maximum stored energy of storage unit

${H}_{\mathrm{min}}^{\mathrm{CHP}}/{H}_{\mathrm{max}}^{\mathrm{CHP}}$ :

Minimum/maximum heat production of CHP unit

${H}_{\mathrm{min}}^B/{H}_{\mathrm{max}}^B$ :

Minimum/maximum heat production of boiler unit

${P}_{\mathrm{max}}^{\mathrm{WT}}$ :

Maximum output power of WT

${P}_{\mathrm{min}}^{\mathrm{CHP}}/{P}_{\mathrm{max}}^{\mathrm{CHP}}$ :

Minimum/maximum electrical power production of CHP unit

${P}_t^{\mathrm{electrical}}/{P}_t^{\mathrm{thermal}}$ :

Electrical/thermal demand of REH

R ^U/R ^D :

Ramp-up/down power CHP unit

S ^R :

The value of rated wind speed

S ^CI/S ^CO :

The value of cut-in/cut-out wind speed

10.1.3 Variables

ξ _ω :

Auxiliary variable used for CVaR computing

${\upsilon}_t^{\mathrm{CHP}}$ :

Binary variable depicted on/off state of CHP unit

π _ω :

Probability of ωth scenario

${E}_t^s$ :

Amount of stored energy in energy storage at tth hour and ωth scenario

${E}_{t,\omega}^{s,\mathrm{ch}}/{E}_{t,\omega}^{s,\mathrm{dis}}$ :

Charging/discharging of energy storage

${H}_{\omega, t}^B$ :

Thermal generation of boiler unit at tth hour and ωth scenario

${H}_{\omega, t}^{\mathrm{CHP}}$ :

Thermal generation of CHP unit at tth hour and ωth scenario

${I}_{\omega, t}^{\mathrm{PV}}$ :

Solar radiation

${P}_{\omega, t}^{\mathrm{PV}}$ :

Utilizing solar power

${P}_{\omega, t}^{\mathrm{WT}}$ :

Utilizing wind power

${P}_{\omega, t}^{\mathrm{CHP}}$ :

Power generation of CHP unit at tth hour and ωth scenario

${P}_{\omega, t}^{A,\mathrm{WT}}$ :

Available wind power at tth hour and ωth scenario

${P}_{\omega, t}^{g,\mathrm{grid}}/{P}_{\omega, t}^{e,\mathrm{grid}}$ :

Purchased gas/power from the grid at tth hour and ωth scenario

S _{ω, t} :

Wind speed at tth hour and ωth scenario

${T}_t^{\mathrm{Out}}$ :

Environment temperature

${u}_{\mathrm{SU},t}^{\mathrm{CHP}}/{u}_{\mathrm{SD},t}^{\mathrm{CHP}}$ :

Binary variable depicting start-up/shutdown status of CHP unit at tth hour

VaR:

Value-at-risk (VaR)