Often overseen as an important item of a solar system, the solar modules are those components which converts the energy from the sun to direct currrent (DC) electricity. Direct current flows as a constant curret between two points.
The rate at which the electricity is converted is measured in watts, often expressed in killowatts (kW) to denote thousands of watts. This is also referred to as the power delivered. Typical instalations measure a couple of killowatts in size.
Because of the nature of the energy source and factors such as the angle of attack of the sun rays in relation to the sun, the energy delivered from this conversion is never constant.
Throughout the day, all the power delivered at a particular time, added together for the time the sun shines, provides us with the yield. A typical yield curve for a fixed solar installation will follow a bell shape with lower yield in the mornings and evenings with a peak around midday. The maximum rate at which a solar module can deliver power is measured in Watt-peak (Wp). The yield is measured in Watt-hours which forms the basis of all electrical energy calculations and billing frameworks.
Quality solar modules will ensure optimal yield with the least amount of coverage.
Solar arrasy should be designed to deliver the required yield for the application it is intended for. It is therefore important to understand the trade-offs whould this component of solar systems be targeted with the intent to bring down the cost of an installation.
Great care needs to be taken in the commissioning of the array to minimise system losses too. Cheaper installations tend to be done with inverior products which increases losses and therefore system yield.