I am to design a laboratory experiment to compare the energy conversion rates of two standard methods for solar energy to be 'trapped' for domestic use. See below*. I need to compare the two systems and find out which is more efficient. The energy source should be a standard 150W light bulb connected to the 230V mains. I know to work out efficiency between the two methods use the equation: input energy/output energy x 100. (Is that correct) How would i set up the solar cell to measure the power output of the cell and how would i set up the experiment to measure the rate of heating of water by the bulb. * The two standard methods for solar energy to the 'trapped' are as follows: 1. To use a solar cell (photovoltaic cells), this converts the radiation energy to electrical energy. (First system) 2. To use a solar panel (an array of pipes on the roof), which absorb the solar radiation to heat water.