Page 54 - Analysis and Design of Energy Geostructures

Energy and geotechnologies 23

and appliances, and technologies harvesting on-site renewable energy
sources. The main purpose for the design of such constructions is to
develop buildings with significantly reduced energy consumption com-
bined with the increased use of low-carbon energy sources to meet this
consumption.
k. In which country/countries has the definition of NZEB been extended to posi-
tive energy building?
i. Switzerland
ii. France and United Kingdom
iii. Italy and France
iv. France
l. Geothermal energy is the natural thermal energy contained in the Earth’s
surface. It results from the formation of the planet, the radioactive decay
of minerals, and the solar energy absorbed at the surface.
Excluding a shallow layer typically sensitive to atmospheric condi-
tions, the temperature increases with depth in the Earth’s crust. The

average geothermal gradient is of approximately 3 C per 100 m of depth
to the upper mantle. This value depends on the location and can be

assessed as 1 C per 100 m in ancient continental zones. At greater depths,

this temperature gradient decreases to approximately 0.1 C per 100 m of
depth.
m. The temperature field in the subsurface, in the worst case, is sensitive to a varia-
tion of the atmospheric conditions within the first:
i. 4 6m
ii. 25 30 m
iii. 40 50 m
iv. 80 100 m
n. In general, shallow geothermal systems can be exploited:
i. To produce heat and electrical power
ii. To produce power
iii. To produce heat
iv. None of the above