Went to my Parents house yesterday and checked out their electrical panel, it's a Square D QO just like what I have at home.
There is room to add a 2 pole 30A breaker. there are two in there right now for the air conditioner and something else.
The Leviton Receptacle should be here tomorrow, I just need to start, I think I have some free time Friday.
(I know somebody is going to post that the total amps on the breakers is more than 200A but I'm not interested. Don't waste your time. If I add up mine it's the same way. In 5 years I've never blown my main breaker. So I never use more than 100A at the same time. The only breaker I ever blow is one in the kitchen that runs my coffee machine and microwave. That's it. One day I'll run a new circuit for just the microwave oven.)
I need a 2 Pole 30A breaker like this one: should be around $15