Exergy Analysis of a Hybrid Solar–Wind–Biomass System with Thermal and Electrical Energy Storage for a Community

Abstract

Sustainable community energy systems often require integration of renewable energy systems with energy storages. Here, a hybrid solar–wind–biomass system with thermal and electrical storages is proposed to supply continuous and reliable energy to a typical Ontario community. Exergy analysis is applied and indicates that a 1,800 m² parabolic trough collector with a wind turbine (16 m rotor radius) and anaerobic digestion can meet the energy needs of a community of 50 households when thermal and electrical storages are utilized and that the steam turbine and space heating components offer the best potential for improving the overall efficiency.

Nomenclature

A _C :

Solar collector area, m²

a _s :

Solar azimuth angle degrees

a _w :

Collector azimuth angle degrees

c :

Scale parameter, m s⁻¹

C _n :

Clearness number dimensionless

C _P :

Power coefficient dimensionless

ex :

Specific exergy, kJ kg⁻¹

$\dot{E}x$ :

Exergy rate, kW

h :

Specific enthalpy, kJ kg ⁻¹

i :

Incidence angle degrees

k :

Shape parameter dimensionless

k _C :

Local extinction coefficient dimensionless

KE :

Kinetic energy, kW

$\dot{m}$ :

Mass flow rate, kW

$\dot{Q}$ :

Thermal energy rate, kW

R :

Rotor radius, m

s :

Specific entropy, kJ kg⁻¹ K⁻¹

T :

Temperature, K

$\dot{W}$ :

Work rate, kW

WS :

Wind speed, m s⁻¹

α :

Elevation angle degrees

β :

Collector tilt angle degrees

η :

Energy efficiency %

ψ :

Exergy efficiency %

ρ :

Density, kg m⁻³

0:

Ambient conditions

BOM:

Biodegradable organic matter

CT:

Cold tank

ETR:

Extraterrestrial radiation

Evap:

Evaporator

Gen:

Generator

HT:

Hot tank

Mech:

Mechanical

MSW:

Municipal solid waste

SH:

Space heating

ch:

Chemical

D:

Destruction

ph:

Physical

Q:

Thermal