Cluster-ID | Cluster | Size | Silhouette | Mean (year) |
0 | Life history | 81 | 0.759 | 2015 |
1 | Renewable energy | 66 | 0.619 | 2014 |
2 | Energy efficiency | 58 | 0.766 | 2014 |
3 | Energy storage | 53 | 0.653 | 2015 |
4 | Oil price | 47 | 0.676 | 2017 |
5 | Power system economics | 46 | 0.752 | 2015 |
6 | Climate change | 39 | 0.71 | 2016 |
7 | Bioenergy | 35 | 0.75 | 2013 |
8 | Scenario analysis | 34 | 0.754 | 2015 |
9 | sensitivity analysis | 29 | 0.743 | 2016 |