49. 图一比较北楼两个备选方案的施工费用和累计业务能源成本，即：(a) 节能大楼；或(b) 装置光伏发电厂的节能大楼。两条线显示每个备选方案的累计能源支出。本图表明，装置光伏发电厂在 25 年期间可以为拉加经委会节省能源成本逾 200 万美元。
49. Figure I compares the construction costs and the cumulative operational energy costs of two alternatives for the North Building, namely: (a) a high-efficiency building; or (b) a high-efficiency building with a photovoltaic plant. The lines show the cumulative energy expenditures for each alternative. This figure indicates that ECLAC would benefit from over $2 million in energy cost savings over a 25-year period with the installation of a photovoltaic plant.