"30kW per day" makes no sense. It's like saying "100km/h per day". W is a unit of power, Wh is a unit of energy.

It's unintuitive because a guy named Watt decided "Joule per second" is Watt, so the intuitive units Joule and Joule per second got turned on their head to W times hour and Watt. This is opposite to usual intuition of distance and speed for example, km and km/h. If I redefined the km/h to a "tick", then a km would become "tick times hour".

If you want a "better than nothing" but imperfect analogy, Wh is how much water you have in a bottle, and W is how quickly you can get the water out.

"30kWh per day" isn't waving away anything.

30kW is a rate.

30kWh is a measure of energy, about 100MJ.

30kWh/day is a rate again, 100MJ/day.

It seems clunky, but it's a way energy usage in a house is typically measured.