What is photovoltaic solar power?

It’s energy from sunlight, captured and converted into electricity by a photovoltaic collector.

Photovoltaic (PV) solar cells use the photovoltaic effect to convert sunlight into electricity. A PV system consists of an array of cells arranged in panels that are connected in series, in parallel or in a combination of the two.

A number of different PV technologies exist, and they are not all at the same level of development. Besides photovoltaic, there are other technologies for generating power from sunlight.

Photovoltaic panels

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PV solar power around the world

The photovoltaic industry has grown considerably in the last decade. Installed capacity has shot up from 1.8 GW to over 400 GW between 2001 and 2017—an average annual growth of nearly 38%.

As in 2016, the photovoltaic market once again broke several records in 2017 and continued to expand worldwide, with nearly 100 GW in new capacity and a total output of close to 500 TWh, equivalent to about 2.1% of the world’s total electricity demand.

At present, 95% of PV systems are connected to a power grid while the remaining 5% are off the grid.

PV solar power in Québec

Though not widespread, photovoltaic solar does have a presence in distributed generation in Québec. At present, there are more than 500 customer-generators using solar energy.

As for large-scale, centralized generation, under the Québec government’s energy policy action plan, Hydro-Québec is to launch a solar development program so that it will have a diversified project portfolio with the flexibility needed to respond to growing electricity needs in an ever-changing energy landscape.

An intermittent energy source

When considered over an entire year, solar energy output is quite predictable. But in terms of output at a given moment, it varies widely according to the season, time of day, weather conditions and cloud cover.

Because solar power is intermittent, customer-generators wishing to have electricity available at all times must use some form of energy storage or be connected to the Hydro‑Québec grid. In the latter case, they can take advantage of the utility’s net metering option.

Québec enjoys plenty of sunlight in summer and at noon, but little or none in the morning and evening during the winter, which is precisely when demand peaks on the Hydro-Québec grid. For this reason, large-scale centralized solar generation is not well-suited to the load profile in Québec, particularly in its northern regions.

Daily sunshine levels in Canada vary by region. Southern Québec, where most of the province’s population is concentrated, has more solar potential than Germany and about as much as Japan, which are among the world leaders in PV solar energy.

Photovoltaic panels

Are you interested in installing solar panels? See our Web site to learn more about PV solar power before you invest.

Efficiency, load factor and cost

Over the past decade, the average efficiency of commercially available crystalline silicon solar cells has risen about 12% to reach 17–17.5%.

All photovoltaic technologies available on the market are more efficient in cold weather; as a result, their output for a given level of solar exposure can be up to 30% higher in winter than in summer.

The annual load factor also varies from one region to the next according to solar exposure: the average is about 15% for Canada and 25–30% in the sunniest parts of the U.S. System performance depends somewhat on climate but mainly on the intensity of the sunlight hitting the ground and the conversion efficiency of the PV technology used.

The main obstacle to the growth of PV solar power remains the cost upfront. Over the last decade, an entire industry has sprung up thanks to generous development incentives, especially for systems connected to power grids. In recent years, however, costs have come down considerably, resulting in the phase-out of incentive programs. Today, in some parts of the world where sunshine is abundant and/or utility electricity is expensive, photovoltaic solar power has now become competitive.

Québec: A special case

In Québec, the cost of a small PV solar power system for a home is still (in 2018) far greater than the cost of electricity from the Hydro-Québec grid, which is very low.

Advantages and disadvantages

Advantages

  • Little maintenance required and low operating costs
  • Long service life (20–30 years)
  • Stable quantity of sunlight available year after year
  • Innumerable potential sites (buildings, open spaces, parking lot canopies, etc.)
  • Optimized output if a storage system is used (which, however, would increase the initial outlay)
  • No moving parts, which reduces noise, visual impact and maintenance
  • Variable size and scalable or modular design, with cells added as required

Disadvantages

  • Intermittent output: variable in daytime, zero at night, sometimes difficult to predict depending on time of day, weather conditions and season
  • Ground-based systems require considerable space
  • Performance diminishes slightly over time

Environmental Impacts

The main environmental impacts of large, ground-mounted photovoltaic systems are as follows:

  • Large surface area, but smaller than those of other renewable or conventional energy sources
  • Limited visual impact, depending on the number of cells and their size, color and light reflection
  • No noise
  • Little water needed (only for washing the panels)
  • Increased risk of soil degradation, especially in arid zones
  • Impact on natural habitats, land fragmentation and disruption of wildlife
  • Little direct impact on biodiversity in the case of built environments
  • Possible conflicts with other land uses: farmland, roadways and access roads, woodlands and built environments (impact on property values)
  • Very few toxic materials used in manufacture
  • Zero GHGs and air contaminants emitted during operation
  • Small life-cycle impact