No I haven't installed one.
No, the savings are not what they are cracked up to be.
Non-photo-voltaic types have been around for at least 30 years and work by trickling water through a 'radiator' exposed to the sunlight. That heats the water up. The heated water can supplement the hot water supply system in the summer and shoulder seasons. Needs to be connected via a decent control system that concentrates the heat.
Solar power is the conversion of sunlight into electricity, either directly using photovoltaics (PV), or indirectly using concentrated solar power (CSP). Concentrated solar power systems use lenses or mirrors and tracking systems to focus a large area of sunlight into a small beam. Photovoltaics convert light into electric current using the photoelectric effect.