In order to solve this problem, use the following equations and steps shown: \begin{align} &\cssId{Step1}{E_{LED} = \frac{P_{LED}}{P_{VSAP}}·E_{VSAP}}\\[3px] &\cssId{Step2}{E_{LED} = \frac{36W}{100W}·123660 kWh=44,517.6kWh}\\[3px] &\cssId{Step3}{c_{save} = c_{VSAP}+c_{maint}-c_{LED}}\\[3px] &\cssId{Step4}{c_{save} = c_{VSAP}+c_{maint}-c_{electr}·E_{LED}}\\[3px] &\cssId{Step5}{c_{save} = 16,941+14,000-0.1370·44,517.6}\\[3px] &\cssId{Step6}{c_{save} = 24,842.08 euros}\\[3px] \end{align}