Solar modules or panel are made up of individual solar cells. The cells contain two layers: one positively charged layer and a negatively charged layer. When light shines on these cells, electrons bounce back and forth between the layers, creating voltage. Each cell generates approximately 0.5 volts DC. These cells are wired, in series, to create a nominal voltage (typically 12 or 24 volts DC).
Solar modules are typically mounted to a rack on the roof or on the ground at an angle. The most effective angle in our climate is 35 degrees. The most effective direction is south.
Because solar modules create DC electricity and houses and businesses typically consume AC electricity, the power must be converted to AC using an inverter. These inverters can be either battery-based or battery-less, which is most common with grid tie systems. The inverter converts the power to AC and the power feeds into the electrical service panel. From there, it is consumed by the local loads or fed back to the grid if not being used.
This arrangement with BC Hydro is called Net Metering. This program allows customers to produce a portion of their power onsite. BC Hydro monitors the inflows and outflows from the meter and creates “credits” for excess energy sent back to the grid. This works especially well in our climate where we receive an abundance of sunlight and long days during the summer months, but we receive very little sun in the winter months. In the summer, a customer can build up credits during the long, sunny days and use those credits during the winter when energy consumption is greater.When a power system is grid tied it is connected to the utility provider such as BC Hydro. By connecting to the grid you do not need batteries to provide peak loads and you can sell excess electricity to BC Hydro through the net-metering program. Batteries can still be part of the system if you wish to have a backup for use during power outages.