Under the deal, the UK government could apply feed-in-tariff to Irish wind projects. This would help the UK meet its 2020 target of generating 15 percent of its electricity from renewables.
Ireland can meet a large proportion of its 2020 renewables target from onshore wind.
Electricity would be transferred to the UK via an electricity connection being developed between Dublin and north Wales. The line is set to be complete by the end of the year.
Irish Wind Energy Association chief executive Michael Walsh said Ireland could generate as much as 6GW from offshore wind.
Walsh said Ireland only needed to generate 5GW to hit its 2020 target, which would allow it to export the remainder to the UK.
Ireland currently has only one offshore wind farm, the 25MW Arklow Bank project in the Irish Sea.
Speaking about the agreement, UK energy minister Charles Hendry said: "There is a massive potential source of clean, green, secure energy that remains untapped in the Irish Sea and onshore in Ireland, as well as around the Channel Islands. But because Ireland's energy demand is only slightly larger than that of Yorkshire and Humberside, there has been little incentive to exploit the resource.
"Optimising the natural renewable resource available around our islands would benefit us all. It makes much more sense to develop and share clean, green, secure energy with our neighbours than import vast amounts of fossil fuels from far flung parts of the world."