The house I recently bought has 100A electric service. The previous owners had a gas dryer, but I already have an electric dryer, and want to use it. Unfortunately, there's no 240V plug for a dryer, and electricians I've talked to are telling me I need to upgrade my service to 150A if I want to add an electric dryer. I figure there are smart folks here who might be able to double check their math.

Here's a picture of my breaker panel:


There are no more usable spaces on the panel, so I'd probably have to do have a sub-panel installed if I keep the 100A service. The big-ticket electric appliances in my house are the A/C, range/oven, and dishwasher. The water heater and furnace are gas-powered.

I can just buy a gas dryer for ~$350, whereas upgrading to 150A service will cost almost $1000. If I'm really at the limit of what 100A service can do, it might make sense for me to upgrade, but if there's room for my dryer with my existing setup, I'd rather upgrade later. Has anyone run into this kind of problem before?