If you invest in a large solar energy system, you could actually make money off of it. If you can pull enough solar power with a collection of solar panels, you may be able to sell your excess electricity to neighbors or even the power company. Contact your local company to see if this could work for you.
Carefully consider the types of solar panels you plan on having installed. Long ago, if you didn't have enough roof space, you'd need very expensive high efficiency mono-crystalline panels. There are now more advanced polycrystalline panels and even thin film panels. If you've got enough roof space, you might wish to look at the size of the panels in relation to their output capacity to avoid having insufficient panels that you need more of later.
See how best practice design principles come together in home design.
If you are comparing prices on a solar energy unit, make sure you are comparing apples to apples. Some companies might offer bargain priced systems, but these systems might not hold up, be backed by a credible warranty or function in a way that really saves you money. Keep in mind that sometimes it is better to spend a little more now so that you save a lot more in the long run.