We currently make around 1 TW of photovoltaic cells per year, globally. The proposal here is to launch that much to space every 9 hours, complete with attached computers, continuously, from the moon.
edit: Also, this would capture a very trivial percentage of the Sun's power. A few trillionths per year.
However, the amount of available land is fixed and the demand for its use is growing. Solar isn't the only buyer in this real estate market.
Availability of land for solar production isn't remotely a real problem in the near term.