SAN FRANCISCO — Apple will invest $850 million in a solar farm in Monterey, California, CEO Tim Cook announced Tuesday.

When completed, the farm will power Apple's Cupertino-based campus, a data center and 50 of the company's retail stores. Cook made the announcement during the Goldman Sachs Technology Conference in San Francisco on Tuesday.

"We're doing this because it's right to do," Cook said during his talk with Goldman Sachs President Gary Cohn. He also noted the move is "good financially," and the company expects "significant savings."

@Tim_Cook: @Apple building 1st solar farm — enough power for Apple II campus, every other office in Calif & 50 stores in CA. #GSTech2015 — JP Mangalindan (@JPManga) February 10, 2015

Cook wore the Apple Watch on stage, and said he is "super excited" for third-party apps for the wearable. He mentioned the smartwatch's potential to help people be healthier and called out an app that will "tap" the wearer when he or she has been sitting down for too long.

* @Tim_Cook on Apple Watch: "If I sit for too long, it will actually tap me on wrist to remind me to get up and move." #GSTech2015 — JP Mangalindan (@JPManga) February 10, 2015

Cook also touted the slew of new Apple products and software updates the company launched within the last year, including the iPhone 6, iPhone 6 Plus and iOS 8.

Apple's chef executive also talked at length about the importance of Apple's recent partnership with IBM. "When you look at it, the skills of two companies are very complimentary," Cook said, hinting there was much more to come from the enterprise-focused partnership between the two companies.

* @Tim_Cook on IBM partnership: "Apple has incredible devices companies want to deploy. IBM doesn't have that." #GSTech2015 — JP Mangalindan (@JPManga) February 10, 2015

"This is not a small thing, the truth is the enterprise has not moved to mobility in the same way the consumer has."

Apple also reached a new milestone Tuesday, ending the day with a market cap over $700 billion, the first U.S. company to do so.