Company officials say their new Madrid office complex will have more than 16,000 solar panels, Cellular-News reported.

Those panels will run the length of the entire office complex on the building rooftops, and will be able to generate approximately 3 mega-watts at peak power, which translates into over 3.6 gigawatt hours per year.

Officials estimate that the design will enable Telefonica to reduce their winter heating bill by 15 percent. They will see a 34 percent reduction in air conditioning during the summer months.

The buildings will also feature rainwater collection units for recycling and watering the grounds.

Structural engineers Arup noted that the one of the main difficulties with the project has been to secure a water-tight design of the internal skin while allowing the glass fins anchors to pass through. The glass fins must support dead load, wind and lateral load of the external skin -- where the solar panels will be fitted -- and transmit all these loads to the structure.

The buildings will look like a group of ice blocks, since all the inside skin glass is ceramic fitted in white dots.

Telefonica is one of the largest fixed-line and mobile telecommunications companies in the world.