What are the qualities on an ideal source of energy ?

Explanation

### Step-by-Step Solution:

1. **High Energy Output**: An ideal source of energy should produce a large amount of energy per unit. This means that for a given quantity of the energy source, it should yield a significant amount of usable energy.

2. **Economical**: The source of energy should be cost-effective. This means that it should be affordable to produce, maintain, and use, ensuring that it is accessible to a wide range of people and industries.

3. **Environmentally Friendly**: An ideal energy source should be pollution-free and smoke-free. This means that it should not emit harmful pollutants or greenhouse gases that could contribute to environmental degradation or health issues.

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