Energy company Contact is closing its 44-megawatt Te Rapa power station in June next year.
"I'm ecstatic because of what it means for Fonterra," Guiney told Rural News.
"When farmers in a co-operative unite behind a board and management team, any future challenge is surmountable - provided we hear their message," she says.
"What I hear is 'move in a direction that builds on the collective strengths of NZ dairy farmers, think long term, and we have your back'.
"That message should not be forgotten."
Guiney says board chairman Peter McBride deserves a lot of credit for this outcome. McBride and mid-Canterbury farmer John Nicholls were also re-elected for another term.
On behalf of the three re-elected directors, McBride thanked shareholders for their continued support at the co-op's annual general meeting in Invercargill last week.
While the three sitting directors weren't opposed, an election was still held as new rules stipulate a successful candidate must get over 50% of the votes to get elected.
Guiney has served twice on the Fonterra board - for three years between 2014 and 2017, before returning as an elected 'non-assessed' candidate in 2018.
She currently chairs the board's safety and risk committee and also serves on the divestment review committee, co-operative relations committee and capital structure committee.
Guiney says her priorities as a board member haven't changed.
"The world wants what we have. If we can better connect our customers to our farmers, and farmers to our customers, we have formidable opportunities," she says.
"Our offshore competitiveness should be our focus; our on farm comparative advantages underpin that.
"We need to enhance, not erode that, and bring the New Zealand public and Government with us."
Fonterra Co-operative Council chairman James Barron thanked shareholders for the high level of participation in the director elections.
"Thanks to all who voted. In doing so you have exericed your right," he told the annual meeting.