By Alison Bevege
SYDNEY, March 17 (Reuters) - Australia's governing Liberal party has won a tight regional election in South Australia, a victory that could deal a blow to national renewable energy plans.
Saturday's poll pitted the conservative Liberals against the state's ruling centre-left Labor party, while independent Nick Xenophon's new party SA Best failed to win the balance-of-power and have the final say over which major party governs.
Incoming Liberal premier Steven Marshall gave his televised victory speech just after 10 p.m. local time.
"It is a tough job, but I tell you what, I'm really looking forward to it .... It's a new dawn for South Australia."
With 63 percent of votes counted, it was expected the Liberals had won 24 of the 47 lower house seats, giving it a majority to form government in what may have national implications for renewable energy policy.
The vote was seen as a choice between solar and wind energy, pushed by Labor, and coal, backed by Australian Prime Minister Malcolm Turnbull's conservative government.
South Australia, the country's fifth most populous state, has the most wind and solar power but the highest electricity prices in the country.
Its 1.7 million citizens suffered repeated blackouts over the last two years when intermittent wind power was insufficient and back-up power from coal and gas was unavailable.
Outgoing Labor premier Jay Weatherill had announced a plan in February to create a network of 50,000 home solar systems backed by Tesla Powerwall batteries.
Turnbull mocked the state's renewables policy as a "reckless energy experiment" that created the highest electricity prices in the developed world.
The federal government wants to introduce a national energy policy that has no renewable energy target but sets requirements for emissions cuts and reliability. South Australia's Labor government had refused to go along with it.
Energy policy specialist David Blowers at the Grattan Institute think-tank told Reuters last week that if the Liberals were to win in South Australia, the federal government could be expected to get the approval it needs to proceed.
The South Australia Liberal party also used a data-mining computer program to intensify lobbying in marginal seats for the first time in this election.
The i360 app imported from the United States uses information gleaned from social media, polls and surveys to pinpoint vacillating voters' addresses and the issues they care about in key marginal seats so they can be targeted for lobbying.
If the data-driven widget is credited with the Liberals' victory, it may become more widely used in future elections.
The official result of the final vote tally may not be known for several days. (Reporting by Alison Bevege Editing by Mark Potter)
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