* Norway set to add 2 GW in onshore wind in 2019-2020
* Foreign investors own about half of onshore farms
* Public opposition threatens future projects
* Regulator imposed moratorium on new projects
By Lefteris Karagiannopoulos and Nerijus Adomaitis
OSLO, Sept 25 (Reuters) - Oil-rich Norway has seen a boom in onshore wind power fuelled by foreign investment, but future growth is at risk after a public backlash sparked a moratorium on new projects and prompted wider calls for a regulatory overhaul.
Industry regulator the NVE called a halt to new wind power project approvals in April after a raft of protests to give the government time to work on a framework for new developments.
Public consultations on the plan, which has defined the 13 areas most suitable for onshore wind, are expected to last until Oct. 1, though it is unclear when it could be approved.
Norway is planning to more than double installed onshore wind capacity over 2019-2020 by adding 2 gigawatts (GW) in new projects, with another 0.4 GW expected to come online in 2021.
That would make it the fastest-growing country in terms of installed onshore wind power capacity in western Europe, according to lobby group WindEurope.
Rapid growth in the sector has spurred rising public opposition to wind turbines, which protest groups say visually pollute the landscape and pose a danger to birds.
Protests against the construction of a 60-megawatt wind park on Froeya island near Tronheim, a joint venture of local energy firm TroenderEnergi and Germany's Stadtwerke Muenchen, led to the suspension of work at the site in May.
Police intervened after protesters pitched tents at the site and parked cars along a road built to transport turbine parts in a bid to block construction.
"We will be living in an industrial park for the next 25 years," said Froeya resident Hans Anton Groenskag, 68, who this month co-founded national umbrella group Motvind - 'Headwind' in English - to coordinate local protests throughout the country.
"The government is too weak, and it's trusting private companies too much, gambling with nature," he told Reuters.
A recent survey showed 78 municipalities out of the 101 included in the 13 areas were against onshore wind power.
Norway's rapid growth in wind capacity has been fuelled by the approach of an end-2021 deadline to complete new projects in order to receive a 15-year subsidy - though some investors say falling costs mean subsidies are no longer needed to make a profit.
So far, onshore wind power has attracted more than 41 billion crowns ($4.58 billion) in investment in Norway, including 1.7 GW projects that were completed by end-2018.
The Nordic country has proved attractive to wind power investors due to its combination of strong winds, falling costs and a stable regulatory regime.
"Norway is one of the best countries in Europe to build wind farms. We have some of the best wind conditions," Joakim Johnsen of independent German investment fund Aquila Capital said.
Some politicians are calling for restrictions on private ownership of wind power, or for it to be more heavily taxed, like oil.
Should that happen, "it would be much less efficient for investors to invest in new projects," said Fredrik Lindblom, a partner at law firm DLA Piper's Oslo office, which has been involved in a number of wind power deals in the country.
Andreas Thon Aasheim of Norwegian wind power industry association Norwea said foreign investors were holding their nerve and were still looking to invest in Norway.
However, if NVE's moratorium lasts longer, the project pipeline will eventually dry up, he said.
Another foreign investor, Swiss energy group BKW, a partner in the 1,000-megawatt Fosen Vind project, the largest onshore wind facility in Europe, said public acceptance was the biggest risk for future developments.
Norway's wind power industry is optimistic, partly due to the expected growth in green energy demand as the country seeks to cut its carbon emissions, including from offshore oil platforms.
"We know that Norway will need more electricity and more wind power," Aasheim said.
$1 = 8.9552 Norwegian crowns $1 = 0.9045 euros Editing by Gwladys Fouche