When you think of solar energy, you probably think of huge panels on the roof of your house. You have more options if there is some space on your property. If they are fitted with trackers that follow the sun, and special mounts, they can more efficiently capture the sun's rays throughout the day. Still, it will take a little bit of room.
Be realistic about the costs of having a solar energy system. If you're paying much less than other systems that are around the same size as yours, you may have poor equipment or installation work. Like with many things in life you get what you pay for. Quality installation work and equipment isn't going to be cheap. You may have substantial savings by going with a large company, but other companies may be cutting corners to keep costs down.