As a solar consultant, you can basically conduct a home inspection and give clients a report on their solar options for their particular home and site.
This can range from full-fledged general solar installations that generate electricity to simple solar walkway lighting.
You might want to start by working in a solar products company to become knowledgeable in the solar energy field.
However, to be a consultant, it is often best not to be affiliated with any one company or product and be able to recommend products and options across the field of solar energy.
Photo by LilGoldWmn.