Ontario's largest electricity supplier is investing in "data dots" and other security measures to stop thieves who have already stolen $1.5 million worth of the utility's copper grounding wire so far this year, risking their lives and customer blackouts in the process.

The stakes are too high to do nothing, says Hydro One's director of security, Chris Price, and that's why the company is using the sand grain-sized data dots as identification tags for its wire.

The dots are fluorescent under ultraviolet light and each is laser etched with an identification number that can be cross-referenced to a database listing the source of the wire.

They are already being used in New Brunswick to help scrap dealers identify stolen copper.

Hydro One is also boosting the number of security guards that patrol its transformer and distribution stations and adding more hidden cameras.

"You … have to make sure that the product you're delivering is reliable to the customer," Price said, adding that the cost of the security measures will be passed on to customers, but is expected to reap savings in the long run.

Copper is attractive to thieves because scrap dealers will pay $3.60 a pound. The price of copper has doubled in the last two years, according to the London Metal Exchange.

Hydro One is responsible for 97 per cent of Ontario's electricity transmission system and also owns its largest distribution system, covering 75 per cent of the province.