Matt Hobby works for the National Centre for Atmospheric Science. His role is to design and develop instrumentation and to build prototypes. One of the devices he deals with is an automatic weather station. These are often installed in remote places around the world and need to be powered by solar energy. Voltaic panels are placed in sunny locations to charge lead-acid batteries which will power the weather station. The energy generated by the solar panel must be greater than the power needed, so the size and angle at which the panel will be mounted (the angle of incidence) must be calculated carefully to match the local conditions. The mathematics he uses involves area, angles, and measuring energy used and supplied.