Setting up a 1-node ethereum testnet is not too hard (though it's not especially user-friendly either). I did some work with Ethereum last year, and I ran a 1-n

Setting up a 1-node ethereum testnet is not too hard (though it's not especially user-friendly either). I did some work with Ethereum last year, and I ran a 1-node testnet on my laptop when working on code. The node was mining constantly, but it didn't seem to demand too much from the CPU. No excessive fan noise or heat. Both embark and truffle, two commonly-used frameworks, have modes that exercise the CPU even less, though I found them a bit hit or miss. I'm sure both have improved since, though. I did a quick test run on the main network as well (which wasn't too expensive - maybe 1ETH). You're definitely better off using a testnet! - the turnaround time is much shorter.