Discovercircuits
This site is a one-stop resource for engineers, hobbyists, inventors and consultants alike. It is a collection of information and offers quick solutions to electronic design problems. The site was launched in year 2002 and currently has 30,000+ electronic circuits or schematics carefully cross-referenced into 500+ categories. The site is owned by David A. Johnson, P.E., who is an electronics engineer with over 30 years of practical experience in the areas of analogue and digital design, fibre-optics and RFID. It has a list of websites where you can find different circuits and projects using solar energy.