The party leader also used her speech to call for a Green New Deal to deliver public investment in "green-collar" jobs in areas including renewable energy, which she said could create hundreds of thousands of jobs while helping the fight against global warming and cutting fuel bills.
And Ms Lucas gave her backing to a programme of free insulation to every home in the UK.
The party leader told the BBC she expected to see Green MPs at Westminster in the next two years.
She identified Brighton Pavilion, Lewisham and Norwich South as target seats.
Ms Lucas told the BBC success in local elections, combined with the change to the party hierarchy, meant the Green party were well positioned for success at the next general election.
"I'm confident this is all part of a real coming of age for the Green party and we will be seeing Green MPs at Westminster next time round," she said.
The MEP for South East England - the party's candidate for Brighton Pavilion - beat the only other candidate, Ashley Gunstock, by 2,559 votes to 210 in the leadership vote.
Earlier, Ms Lucas, 47, told the BBC: "We need to redouble our efforts to get our message across even more urgently. We think that by having a leader we can do that even better."
She added the decision to switch from the party's previous system of having two principal speakers followed "the realisation that people don't respond to abstract ideas".
"They respond much more to the people and policies that represent those ideas. We have a face to put to the policies," said the new leader.
Ms Lucas added: "There is a huge number of people out there who want to hear our message and we need to get better at getting it across.
"I want to get our message out about social justice. Everybody knows we're the party of the environment. What fewer people know is that if you are looking for the real progressive force in British politics today it is the Green party."
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