Explain why some energy resources are intermittent.

Some energy resources are intermittent because their availability depends on natural conditions that change over time. Solar power is only produced when the sun shines, and wind energy fluctuates with wind speed. These resources cannot guarantee a constant supply, so electricity generation can vary throughout the day or season. In contrast, fossil fuels, nuclear fuel, and most hydroelectric plants can be operated continuously, providing a steady output. The intermittency of solar and wind means that additional storage or backup generation is often required to maintain a reliable energy supply.