Estimating the Direct Rebound Effect in the Residential Energy Sector: An Application in Spain - Green Energy and Efficiency: An Economic Perspective - page 171

Table 2 CO 2 emissions (in kg CO 2 /m 2 per year) in households using electricity or natural gas for
heating and hot water use
Residential fuel N Avg CO 2 Sd Min Max
Electricity 146 38.89 24.02 10.04 114.78
Natural gas 253 19.91 9.08 5.87 52.38
Note Avg CO 2 = Average CO2 emissions, Sd = Standard deviation, Min = Minimum and
Max = Maximum
Source Own work

Table 2 reveals that homes which use electricity as their sole source of energy
emit more CO 2 on average than those that use natural gas. In the latter there is also
less dispersion, and they account for almost 100 observations more than households
that use only electricity.
Table 3 sums up the results provided by CE3X. Energy ratings range from A
(most ef cient). As expected, as the energy rating moves

towards G the average CO 2 emissions increase in all 3 areas. However that increase
is not linear: indeed, the average CO 2 emissions from households rated G are more
than 10 times greater than the average from the most ef

cient) to G (least ef

cient households.
The data indicate that the energy ratings of dwellings in all three areas are mainly
concentrated at levels C, D and E. Between them these three labels account for
75.8 % of the northern households in the sample, 81.5 % of the central households
and 91.6 % of those from the south. The smallest group in the sample is that of the
households with the lowest average CO 2 emissions.
It is noteworthy that some households with different energy ratings may in fact
have similar CO 2 emission levels. For instance, households labelled D in the North
and E in the South have quite similar average CO 2 emissions. This is because the
rating procedure penalises some households because of their location.
Table 4 shows the variables in the study along with some descriptive statistics.
The data show that, on average, households have three members, and at least one
occupant is employed. In the sample, 36.6 % of household heads are women, 38 %

Table 3 Household energy rating and CO 2 emissions (in kg CO 2 /m 2 per year)
Label

North Centre South

Share Avg CO 2 Share Avg CO 2 Share Avg CO 2

A

1.4 7.15 1.2 5.20 0.3 3.63

B

11.6 12.11 8.5 9.92 1.7 5.67

C

24.7 16.78 20.8 14.32 11.0 8.16

D

24.7 23.48 28.6 22.83 33.8 14.53

E

26.5 40.40 32.0 39.77 46.8 26.24

F

3.3 54.25 1.9 63.47 2.3 39.15

G

7.9 83.23 6.9 93.66 4.0 50.21

Note Avg CO 2 = Average CO 2 emissions
Source Own work