Google reported using 32.11 million MWh in 2024. Average cost per megawatt hour for industrial customers in the US was $87.50, so we can estimate (with wide error bars, but the right order of magnitude) about $2.8 billion in electricity cost for the year. Google's net income in 2024 was about $100B, so electricity costs are a small fraction of profit. Electricity expenses are included in their cost of revenue, which was a total of $146B.
I believe the second-order effect of being able to scale faster will easily swamp the first-order effect of saving money on electricity.