Energy giant SSE has been fined £700,000 by regulator Ofgem for missing last year's target to install gas smart meters for customers.

The watchdog said while SSE met its electricity smart meters installation target for 2018, the supplier only reached its gas target in February this year, less than two months after the deadline.

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SSE has agreed to pay £700,000 to Ofgem's consumer redress fund run by the Energy Savings Trust, which supports consumers in vulnerable situations and the development of innovative energy products or services.

But the watchdog said it had decided not to take formal enforcement action against SSE, due to the steps SSE had taken.

Under the Government's smart meter roll-out programme, suppliers are legally required to take all reasonable steps to roll-out smart meters to all homes and small businesses by the end of 2020.

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They set individual annual targets for smart meter installations as part of this aim and Ofgem monitors performance against these targets.

But there are fears that the 2020 deadline is unrealistic, with recent official figures showing smart meter installation dropped by 16% year-on-year in the final three months of 2018.

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Domestic smart meter installation fell 2% in the final quarter compared to the previous three months.

By the end of last year, 12.65 million smart meters were installed in households, representing a quarter of all domestic meters.

Ofgem said it was "closely monitoring" supplier approaches to the roll out of smart meters and vowed to "hold suppliers to account if they do not meet their obligations".