Mesa 2. Almacenamiento Térmico

Existing solar/wind provides electrons not heat

• Interconversion of heat and power is important • Solar collectors have much higher temperatures available (sun is at

~10,000K) • Ideal applications use the high temperature available • Example could be the thermal cracking of methane

• CH4 2 H2 + C (s) • Solid carbon can be buried • H2 can be burned without CO2 emissions in a high efficiency PEM cell

Carnot, modified Carnot, isentropic and 75% isentropic work. Reasonable match between Modified and 75% isentropic work.

10

1075.0 0

rb

rbequivalent

T

TTQW

Steam extracted from steam turbine at pressure P and temperature T

Steam to condenser At 40oC, Pressure~0.1bar

steam turbine 75% efficiency

Work

Work value of steam

Heater

Cooler

Electric Energy

Turbomachines

T2nom = 500 oC

T0nom = 20 oC

Loading step:

High pressure tank (HP tank)

Low pressure tank (LP tank)

-72 ~ -5oC

433 ~ 500oC 870 ~ 980oC

20 ~ 136oC

A. White, et al., Applied Thermal Engineering (2012).

T. Desrues, et al., Applied Thermal Engineering (2010).

Electric energy is converted into sensible heat stored in the solid material

Temperature is regulated at heater and cooler to maintain a constant operating condition and eliminate turbomachine irreversiblities