The electrical world, power is measured in watts or kilowatts that translated also say Watts or kilowatts. Enunciating power in electrical engineering it is referred obviously to the electric power. Remains as understood. The power is a measured baseline, as the speed of a car. The electrical world, power (watts) is a measure of the speed of the flow of energy. Are they qualified to home appliances and devices that consume electricity such as electric light bulbs or the so-called light bulbs or electric motors; both in watts or kilowatts. For example, an electric toaster can be identified as 1000 watts toaster, is saying that the toaster has a power of 1000 watts. A spotlight with power of 100 watts, says simply 100 watt bulb. Now, when mentioned 1.0 kWh or 0.01 kWh is that he is referring to the power consumed in 1.0 hour both the toaster and light bulb respectively. In This time changes your ID to energy. (remember that 1 kW = 1000 watts). Energy = power x time for tariff purposes or commercial purposes is used the term energy, i.e. kWh, or consumption of the kilowatts or kW in the span of an hour. A solar panel with capacity of 5 000 watts of five thousand Watts or 5 kW and 5 kW solar panel can also be said. It is the same, it is the power of the solar panel. On the other hand, energy is the production over time. A light bulb that consumes 100 watts for one hour consumes 100 watts-hours of electricity. If operated for 10 hours, the bulb has produced 1000 watts-hour of power. They are measures of production or consumption of energy. A photovoltaic system or a 50 watt solar panel means that this panel produces 50 watts, its power is 50 watts. If this panel It works for 5 hours a day because its production or energy consumption will be 250 watts-time in a day. If you work for six days his production will be 1500 watts-time which the same is to say that in six days the panel there has been 1.5 kwh of electric energy.