Pros
You're doing work that you can feel good about at the end of the day. The company mission is to use the planet's natural resources more efficiently, and you save consumers money and help lower emissions from people's normal routines. The CEO and upper level management are good at what they do, likable, and available to talk to for pretty much anybody at the company. Really does feel more like a "family" than most businesses of this size, and they honestly do care about you as a person. Also, you're working with utilities, so there's less of a hyper-competitive marketplace for the contracts that you're bidding on and working to retain. Work life balance is pretty good, especially if you're not a workaholic already.
Cons
Starting salaries are pretty low and compensation levels don't make any sense in most cases. There are people who are absolutely vital to the day to day operations of the office making ~$15k less than some others who basically just delegate work and kick the theoretical can down the road. If you do manage to make it past an entry level position, the difference between what you make and what a person with the same job title and description makes can be $20k. Not a lot of transparency in that aspect so it's important to talk frankly with your coworkers and understand if you're on the wrong end of that equation. Depending on your manager and situation, it could be something that you address once, maybe twice a year. But at the end of the day if you're a top 20% performer looking for a competitive paycheck then this may not be your #1 option. As with most companies, there seem to be a certain number of people who just continue floating on teams through the months without providing much actual value, but somehow make more money than you will. So be prepared to come to terms with that. Also, you better like long meetings, because there's more than enough of those to go around.