## Solar Success Factors

This is an overview of how solar PV production is influenced by a number of factors. But first you should understand how production is measured. Solar PV numbers can be confusing at time. Let's try to make is as simple as possible:

Solar radiation, also called insolation, is a measure of solar energy on a certain surface of the earth. For photovoltaics, it is usually measured in kWh per kWp per year (kWh/kWp/year). This measurement provides the information of how many kWh can be produced in one year if you use for example four 250 Watt panels (1 kW) at this location. [1]

### Tilt and Orientation

The sun’s path is an important factor in optimizing the energy output of the panels. An ideal orientation for your solar panels is true south. An ideal tilt of the panels is somewhere between 25 and 35 degrees in Ontario. In locations close to the equator the perfect tilt is around 0 degrees.

Shading is a big concern when it comes to solar PV. Before making a decision any shading that may be occurring over a time frame of 20 years needs to be factored in. Also consider trees that will grow over that period. In a partly shaded area, micro-inverters might make sense. In contrast to central inverters, micro-inverters will allow the panels to produce electricity independently of each other.

### An Example

Let's assume you installed four solar panels, each 250 Watt peak on your south facing roof. Your roof has a tilt of 30 degrees. The following are the kWh this kind of system would produce per year in different Ontario cities according to Natural Resources Canada[2].

#### kWh/year

Toronto 1173
Ottawa 1198
Thunder Bay 1224
Kingston 1197
Kitchener 1153
Windsor 1221
Peterborough 1188
London 1166

To calculate your return, multiply your energy production times the FIT rate paid per kWh and you will have your revenue per year.

There are other factors that will also influence your system production. We do not want to into too much into details, but will just name a few:

• Temperature
• Inverter efficiency
• Cabling
• Configuration of system
• Others…