Very simple. There is a substance called Helium-3. It's a kind of isotope used in Nuclear Fission. It is EXTREMELY rare on earth, but is quite plentiful on the moon.
The advantage of this substance is that it has absolutely no radioactive byproducts or waste. It is completely safe. It is extremely efficient, and only a single shuttle loaded with it would be enough to power the entire United States for a year!
But, on earth, it is rare and expensive. Current nuclear power plants can process Helium 3 without danger of radioactive waste.
It's really quite the energy source of the future. Imagine if a Canadian agency could get their hands on it! The good it would do for the environment on earth! Electricity would be cheaper and cleaner, and it would perhaps make an excess of energy reservoirs, making fossil fuels a thing of the past.
Also, keep in mind that the biggest and most advanced mining corporations in the world are Canadian.
I don't think Canada should do it alone, but a joint venture with the United States and the EU would be highly profitable.