In stellar terms, tiny. In human terms, huge. Googling suggests that global energy usage is estimated to be around 15 terawatts. Using the most efficient mult

In stellar terms, tiny. In human terms, huge. Googling suggests that global energy usage is estimated to be around 15 terawatts. Using the most efficient multi-junction solar cells available - which can convert 30% of the light hitting them into electricity - we could generate that with about 6.5 million km² of solar panels: that's about 80% of Australia. Out at Earth's orbit, it'd need to be 68 million km^2: about the area of the Indian Ocean.