Can there be unlimited supply and unlimited demand?

No. Once it has all been used up, it'll be gone. And its non-renewable, which means once we use it, we cannot use it again. In fact, in many places of the world people are running out of oil....

Tidal energy is a renewable energy resource. This means that it will not run out.

No, that's why they come in packs, because they always use up their fuel. Were they to have unlimited energy, you would never need to replace them or recharge them.

No. The earth is 70% water, and less than 1% of that is drinkable. The earth doesn't "Make" water as fast as we need it, and we can't purify the seas.

Glut. There was such a glut of oranges that year, the growers got almost nothing for them at the market. Many farmers just left them to rot on the trees.