What is photovoltaic solar power?
Photovoltaic solar power is generated by using solar cells to collect the sun’s energy and transform it directly into electricity.
Solar cells use the photovoltaic effect to convert sunlight directly into electricity. A photovoltaic system consists of an array of cells arranged in panels that are connected in series, in parallel or by both methods.
There are a range of photovoltaic technologies, and they have reached different levels of development. In addition to photovoltaics, there are several other methods for generating solar power.
Current state of knowledge
The photovoltaic industry has made a lot of progress in the last decade. Its installed capacity shot from 1,790 MW to 137,000 MW between 2001 and 2013, an average increase of 40% per year. In 2013, photovoltaic solar power accounted for about 1% of the world’s total electricity output and 4% of the available installed capacity.
Photovoltaic systems connected to a power grid represent 95% of the current market, with off-grid systems representing the remaining 5%.
In Québec, centralized photovoltaic solar power generation is in the experimental stage. While distributed generation does exist, it is still very rare.
The availability of solar energy varies: the amount of sunshine depends on the time of day, weather and season, and it can be difficult to predict. Daily sunshine levels in Canada also vary by region. In Québec, solar energy is unavailable in the winter peak demand period (mornings and evenings). As a result, photovoltaic systems must be adapted to the wide swing in sunlight levels we experience between the summer and winter, especially in northern Québec.
This fluctuating availability of solar energy has a number of technical repercussions for photovoltaic systems connected to the transmission system in Québec, especially if the total or local installed capacity becomes significant. Ultimately, these technical constraints will have an impact on the choice of power generation system, in light of the costs involved.
In southern Québec, where most of the population is concentrated, the average annual load factor for photovoltaic systems is close to 16% or 17%. That is higher than in Germany and Japan, even though they are the leaders in the global photovoltaic solar power industry.
Output and costs
In 2014, energy conversion efficiency for photovoltaic modules used in electrical microgrids averages 15%. The efficiency rate for multijunction cells exceeds 40%, but their production cost is still too high for large-scale use. Photovoltaic technologies have varying levels of sensitivity to temperature, and as a result their efficiency and output for a given level of sunshine can vary by up to 30% between summer and winter.
The main obstacle to the growth of photovoltaic solar power remains the upfront costs. 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, those costs have come down considerably.
In Québec, the current upfront costs (2014) for small photovoltaic systems connected to a power grid are still higher than for wind power or hydroelectric projects (Hydro-Québec projects).
Advantages and disadvantages
- Intermittent output that varies depending on the time of day, weather and season and can be difficult to predict
- Output optimized through the use of energy storage systems
- No moving parts
- Scalable or modular design (with modules added as required), making it possible to increase installed capacity, and variable size
- Reliability and long service life (about 30 years)
- Little maintenance required and low operating costs
- High site potential (buildings, parking lot sun shades, open spaces, etc.)
- Ground-based system requiring considerable space
The main issues for large-scale photovoltaic systems are the following:
- Visual impact: number of units, size, color and light reflection
- No noise
- Obstacle to rain runoff and partial soil sealing (depending on system foundation)
- Use of large quantities of water for cooling and cleaning purposes, production of wastewater
- Increased risks of soil degradation, including erosion
- Impact on natural habitats and disruption to wildlife
- Possible conflicts: farmland, access roads, woodlands and built environments (impact on property values)
- Use of toxins during manufacturing
- Zero greenhouse gas and atmospheric contaminant emissions during operation
- Small environmental impact over the facility’s life cycle
To learn more about photovoltaic solar power, see the data sheet.
- The photovoltaic effect
- Types of technologies
- Methods of generating solar power
- Intermittent and daily sunshine
- Average cost of photovoltaic modules
- Systems and power grids
- Climate change and air quality
- Life cycle assessment
- Ecosystems and biodiversity
- Health and quality of life
- Land use, regional economy and social acceptability