The 12GW target in the country’s Climate Action Plan includes at least 3.5GW of offshore renewable energy and up to 8.2GW of new onshore wind capacity.
Renewable sources contracted under corporate power purchase agreements (PPAs) should also meet 15% of Ireland’s electricity demand by 2030 under the plan.
Increasing onshore and offshore wind capacity is the most economical options for meeting the 70% target, the plan suggested.
The government vowed to enshrine these measures in law in a new Climate Action Act, which would also include a 2050 target for net zero greenhouse house emissions.
The Irish Wind Energy Association (IWEA) described these targets as "ambitious, but absolutely achievable", adding that "new battery technologies, greater interconnection and a stronger grid" would help Ireland meet the target.
"For the first time we have a government vision for how we can decarbonise Ireland’s energy system," said IWEA chief executive David Connolly.
The plan included provisions to close peat and coal plants and replace them with renewable capacity.
It also suggested increasing renewable capacity to meet the rising power demand as the transport and residential heating sectors are electrified.
Streamlining the consent system, connection arrangements and funding supports for new energy technologies will be required to meet the 70% renewable target.
By the end of the year, the government should ensure that updated planning guidelines for onshore wind are published.
Applications are due to open in the first clean energy auction under Ireland’s renewable energy support scheme by the end of 2019.
The government should also examine using further cross-border joint cooperation mechanisms for funding renewables, particularly offshore wind, to reduce the cost impacts on Irish consumers and businesses, the plan stated.
In addition, the government should support ocean energy research — including demonstration floating wind technologies — and examine how to maximise the supply chain and enterprise opportunities in these areas.
The Climate Action Plan would be updated annually with actions reported on quarterly.
Environment minister Richard Bruton, who introduced the climate action plan, said: "This plan sets out radical reforms that will cut our reliance on carbon, making our businesses more competitive, our homes more sustainable and our farms more efficient.
"Most of the actions set out will actually save money in the long-run."
WindEurope’s head of advocacy and messaging, Viktoriya Kerelska, said: "It’s excellent news that the Irish government is ramping up its ambition on renewables."
She added: "What is also good is that the Irish government takes active steps on the electrification of heating and transport. They’ve announced steps to help consumers switch from gas boilers to heat pumps and from diesel cars to electric vehicles.
"As countries start to finalise their National Energy and Climate Plans for 2030, Ireland is showing the way not only in its ambition on renewables, but also has the policies to make this ambition a reality.
"Other countries should take note."
Ireland currently has just over 3.5GW of wind power capacity, according to Windpower Intelligence, the research and data division of Windpower Monthly. The vast majority of this is onshore.