Maybe something along these lines. Adjust as necessary.
load out
figure('Position',[1 1 1000 400])
N = size(out.emissions.today,1);
h_s = bar(out.emissions.today{:,[10 12]},'stacked','BarWidth',1/3,'XData',(1:N)-1/3,'FaceAlpha',0.5,'EdgeColor','none');
h_s(1).FaceColor = [0 0 0.5];
h_s(2).FaceColor = [0 0 1];
hold on
h_us = bar(out.emissions.today{:,[7 13]},'BarWidth',1,'XData',(1:N)+1/6,'FaceAlpha',0.5,'EdgeColor','none');
h_us(1).FaceColor = [0 0.5 0];
h_us(2).FaceColor = [0.5 0.5 0.5];
legend({ ...
'THG-Emissionen der Stromerzeugung (351 g/kWh)', ...
'THG-Emissionen durch Leckage des Kaltemittels', ...
'THG-Emissionen der Biomassebereitstellung (12 g/kWh)', ...
'Gesamt-THG-Emissionen'}, ...
'Location','SouthOutside','NumColumns',2,'Orientation','Horizontal')
