This page says the ocean is about 352,670,000,000,000,000,000 gallons, which is about 1.3 x 10^21 liters, and each liter is a kg of water (yeah, yeah, the dissolved salt adds some mass but I don't think it adds sufficient thermal mass to make a difference). It takes 4.184 kilojoules to raise 1kg of liquid water 1°C, and 1 joule is 2.778 x 10^-4 wh.

So that's 1.55 x 10^18 watt hours, or 1,550,000 TWh.

Global electricity consumption is about 30,000 TWh per year, so if you use the entire world's electricity consumption for 51 years you'd raise the oceans' temperature by 1°C.

Or if you take global data center power capacity of about 125 GW, and ran them at full power 24/7, you'd be producing about 10.8 TWh per day or 3944 TWh per year. It'd take about 393 years of the world's data centers to raise the ocean by 1°C.

Just goes to show that much more of the energy heating up our world and our oceans is coming from the sun heating up the planet and the planet failing to radiate it out past our greenhouse blanket, not from the actual heating of our atmosphere from our own energy sources.