*4.3. The Results of Energy Consumption Function*

The results of the estimated energy consumption function are shown in Tables 6 and 7, the results show that these estimates are consistent, and the number of instrumental variables is significantly less than that of all model countries. According to the model estimation results, it can be seen that: firstly, the coefficient of the green economic growth variable shows a positive value in the sample group of OECD countries, indicating that green economic growth can promote renewable energy consumption. In contrast, according to the estimation results for the sample of non-OECD countries, the relationship between green economic growth and the renewable energy consumption is the opposite. Secondly, for the effect of industrialization on renewable energy consumption, industrialization is able to promote renewable energy consumption in OECD countries, while in non-OECD countries, the effect of industrialization on renewable energy is negative. This may be due to the fact that most of the OECD countries are more developed economies and therefore have more developed industries and more diverse and sophisticated energy systems than the non-OECD countries. Whereas the non-OECD countries, most of which are developing

**Variables Group (1) Group (2) Group (3) Group (4) Group (5) Group (6) Group (7) Group (8) Diff-GMM Sys-GMM Diff-GMM Sys-GMM Diff-GMM Sys-GMM Diff-GMM Sys-GMM** L.e 0.835 \*\*\* 0.947 \*\*\* 0.844 \*\*\* 0.939 \*\*\* 0.767 \*\*\* 0.943 \*\*\* 0.774 \*\*\* 0.947 \*\*\* (0.0649) (0.0187) (0.0534) (0.0274) (0.0820) (0.0316) (0.0852) (0.0288) geg 0.171 \*\*\* 0.117 \*\*\* 0.0328 0.0581 0.217 \*\*\* 0.0977 \*\*\* 0.0791 0.0673 (0.0482) (0.0371) (0.0634) (0.0460) (0.0499) (0.0323) (0.0691) (0.0438) ind <sup>−</sup>0.131 0.0472 0.122 0.143 \*\*\* <sup>−</sup>0.223 \* <sup>−</sup>2.92 <sup>×</sup> <sup>10</sup>−<sup>5</sup> <sup>−</sup>0.0136 0.135 \*\* (0.0982) (0.0434) (0.141) (0.0523) (0.118) (0.0420) (0.173) (0.0529) ino 0.213 \*\*\* 0.126 \*\*\* 0.186 \*\*\* 0.108 \*\* (0.0664) (0.0488) (0.0696) (0.0500) stemp −0.00681 −0.00893 \*\* −0.00251 −0.00668 \* (0.00440) (0.00444) (0.00445) (0.00401) wtemp 0.00502 \* <sup>−</sup>9.13 <sup>×</sup> <sup>10</sup>−<sup>5</sup> 0.00399 0.000999 (0.00288) (0.00292) (0.00296) (0.00237) Constant −0.138 −0.391 \*\* 0.225 −0.265 (0.208) (0.186) (0.172) (0.195) Observations 630 665 630 665 630 665 630 665 Sample 35 35 35 35 35 35 35 35 AR(1) 0.00326 0.00193 0.00108 0.00109 0.00320 0.00189 0.00170 0.00111 AR(2) 0.865 0.816 0.959 0.843 0.915 0.840 0.976 0.850 Hansen test 0.481 0.734 0.696 0.621 0.495 0.676 0.545 0.525

**Table 6.** The energy consumption function (OECD).

energy consumption.

countries, are at a stage of industrialization where they are using a lot of fossil fuels. Therefore, industrialization in non-OECD countries is negatively correlated with renewable

Note: Robust standard errors in parentheses, \*\*\* *p* < 0.01, \*\* *p* < 0.05, \* *p* < 0.1.

**Table 7.** The energy consumption function (non-OECD).


Note: Robust standard errors in parentheses, \*\*\* *p* < 0.01, \*\* *p* < 0.05.

Compared with similar studies, it is confirmed that innovation input is positive to the renewable energy consumption of OECD countries, and the innovation input is negatively related to the renewable energy consumption of non-OECD countries, which may be due to the fact that compared to developed OECD countries that develop renewable energy technologies, innovation input in non-OECD countries is not reflected in the application of renewable energy. This may be due to the fact that innovation input in non-OECD countries is not reflected in the use of renewable energy compared to R&D in developed OECD countries. Finally, in the results of the estimation of the effect of climate variables on the consumption of renewable energy, the estimates for the OECD and non-OECD country samples are largely consistent, with renewable energy consumption being negatively correlated with summer temperatures and positively correlated with winter temperatures.
