What is solar energy? 

Solar energy is any energy captured from the sun’s rays. Sounds simple, right? It is a renewable source of energy because it is available to use during the day when there are no clouds. However, it is slightly more complicated than that and involves nuclear fusion.  

The sun releases energy through nuclear fusion in the form of electromagnetic radiation (photons) which earth experiences as heat and light. Most of this radiation is absorbed by the earth’s atmosphere. However, some of the remaining radiation can be captured as solar energy directly using photovoltaic (PV) cells.  

What are photovoltaic (PV) cells? 

PV cells, which are used in the solar panels often seen on the roof of a home or business, or in a field, are commonly referred to as a solar array. The PV cells use semiconductors, often silicon to absorb radiation from the sun (photons), which knocks electrons loose. An electrical field then directs the loose electrons into a current (voltage).  

How is solar energy used to generate electricity? 

When the semiconductors are connected in a circuit to an external load (e.g., a battery), electricity then flows in the circuit and can be stored. But that’s not the end of it! PV cells generate direct current (DC) energy, which must then be converted into an AC current using the batteries as mentioned, and inverters.  

Solar panels provide an increasingly cost-effective way to capture renewable energy, especially in areas where there is significant sunlight throughout the year. However, the amount of sunlight varies significantly between regions and throughout the seasons. The availability of solar energy is an important consideration when using it as electricity, as well as demand and battery costs. 

Generally, the province of Nova Scotia receives less sunlight than the Arizona desert in the summer months and even less in the winter months. In Halifax, NS there is an average solar radiation measure of 4.08 kWh/m2 per day, with a high of 5.66 in July but a low of 1.75 in December. By comparison, Phoenix, AZ has a high of 8.12 in June and a low of 4.72 in December. (Source: PVWatts Calculator)

So, if solar energy is to be used when the sun isn’t shining, batteries become an increasingly important part of using solar panels to capture energy, especially if it is needed for electricity at night or on cloudy days. However, battery technology is still not cost-effective to use as a large-scale long-term solution like during the cold winter months.  

What role can solar panels have in Atlantic Canada’s energy future? 

Source: US Energy Information Administration

Solar panels are already being used by households, businesses, municipalities and utilities across the Maritimes. Examples include the City of Summerside’s Sunbank Project, the Shediac Smart Energy Community Project, and Community Solar Gardens in Nova Scotia.  

For residential properties, individual installations and community projects will likely become increasingly common, especially as technology and prices continue to improve. Government or utility funding and net metering programs can help accelerate this adoption.  

Importantly, these types of uses must consider the cost and requirement of being connected to the electricity grid as described above. 

For these same reasons, solar powered energy at a large scale may be more difficult for utilities in Atlantic Canada to consider as a main energy solution. Other renewable energy sources such as onshore and offshore wind farms may see a greater role in region’s energy future, as well as hydro and nuclear will continue to play important roles to provide clean baseload generation. 

Amherst Solar Garden, built by Natural Forces Solar

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Full disclosure: The Atlantica Centre for Energy represents many of the largest energy producers and consumers in Atlantic Canada, including renewable energy. However, the Centre’s members also represent governments, research groups and academia. The Centre examines all types of energy to help decarbonize while growing economies across the region.