Currently, smaller PV systems are being used in a variety of applications, such as rural, remote and portable energy systems – even in satellites orbiting the earth – in situations where grid access isn’t available or practical.

Solar energy projects typically generate energy for the heating of air or water, or to generate electricity for on-site consumption.

In order to encourage the development of larger solar PV generating sites that are connected to Ontario’s distribution system, the Standard Offer Program for Renewable Energy has set a contract price of 42 cents per kilowatt hour – more than three times the offered price for other renewable technologies.

For this type of solar project, the need for batteries to store electricity during low light periods is eliminated. However, a higher standard, heavy-duty inverter will be required to connect to the electricity grid.

Solar panel arrays are often racked and mounted on the ground or on a building. Sometimes they can be integrated into the building’s structure, bypassing the need for a rack. In both cases, the main consideration should be the solar access of the site – so there should be as little shading as possible from trees and other buildings or structures.

The orientation (the angle of the PV panels in relation to the prevailing sunlight) of the rooftop/façade or other structure is also quite important. Experience has shown that orientations yielding the most electricity on a yearly basis are south-facing orientations with an inclination of about 45 degrees.

Other siting issues are:

• Are any major structural changes required?
• Does the installation allow for easy access maintenance?
• Is the structure in good enough condition to last at least 20-25 years?

A significant portion of the costs of a grid-connected PV system are the PV panels. However, manufacturing costs have come down in recent years and further decreases are expected.

For a pre-existing building there are two main components that need to be added to the electrical system:

• PV panels, which currently cost about $4.31 per watt of output
• An inverter that converts DC power to AC power, at a cost of about $1 per watt.

The total cost of a grid-connected PV system, including costs of installation, is about $10 per watt of output – for large systems $10,000 to $14,000 per kW.