Alcoa's Peel office in Pinjarra just got greener, with 242 roof top solar panels switched on this week.

The 79-kilowatt solar power installation has the potential to reduce reliance on power sourced from the electricity grid by up to 50 per cent.

Alcoa has already installed low-energy external lighting at the office that seats almost 100 people as part of efforts to reduce its environmental footprint.

Peel based, Alcoa Land Administrator Warwick Webb who was the driving force behind the project said solar panels were an obvious choice for Alcoa having environmentally and economically sustainable outcomes.

"The decision to implement solar power at the Peel office is aligned with Alcoa's goal to reduce negative environmental impacts," Mr Webb said.

"By introducing solar power we are reducing our carbon footprint, producing an immediate benefit to the environment. The panels will also help to reduce energy consumption at the office that is mainly occupied during the day enabling the renewable energy to be captured and used real-time."