Brown said the industry had come along way in a year but called for it to do more in bringing down the cost of energy.
"Onshore wind is so close, I am not going to get into the argument whether it is a year or five years away.
"This is within our grasp, and that is the message we must feed to government and those making decisions on electricity supply."
"We are no longer the alternative guys with beards and sandals. We must step up to the mark and behave accordingly," he said.
In the welcoming speech at the conference, Brown said he was concerned about the onshore sector, should a majority Conservative Party government be elected in May's general election. Currently, the Conservatives are in a coalition government with the pro-renewables Liberal Democrat party.
But the right-wing Conservative Party was under pressure from the far-right UK Independence Party (Ukip), which is against most forms of renewable energy, in particular onshore wind.
The Conservative Party itself said it would end support for onshore wind if it is in government after the general election and communities secretary Eric Pickles has had an increasing involvement in the consenting procedures for onshore wind projects.
Brown said: "We are concerned about the threat to the onshore wind industry if there was to be a Conservative majority government. We must change their minds. Their views seem to be disproportionately affected by the position of Ukip.
"The Department of Energy and Climate Change minister, Matt Hancock, confirmed his belief last week that onshore wind will be lowest cost form of new build electricity by the early 2020s," he added.
In his speech, Brown also welcomed the increase in public messaging campaigns that have been launched recently. This includes the Offshore Wind Works campaign led by Dong Energy and the British Wind partnership.