Solar Energy is on the Rise

Solar energy is a source of clean, inexpensive, and sustainable energy, yet there is not widespread use. Each photon of sunlight that the Sun discharges can be captured and converted to useful energy. Solar energy is the most abundant energy resource on Earth. Precisely, the Sun provides 10,000 times more ceaseless energy then the total world’s energy consumption, at a rate of 173,000 terawatts continually [1].

The Basics

How are we able to take ‘sun’ and turn it into usable energy? There are multiple mechanisms. The most common way that solar energy is harvested is by using solar photovoltaic (PV) cells, or solar PV panels. Solar PV panels are multiple solar PV cells connected in parallel circuits [2]. 

The term “solar photovoltaic” means converting radiation from the sun into DC electricity with the use of semiconductors (a material like silicon) [3]. When photons in the sun’s rays contact the solar PV panels, electrons are freed from the semiconductor, creating an electric current. Since most appliances take AC current rather than DC current, the DC electricity from a solar PV panel is converted to AC with an inverter [4].

 

Recent Developments

Energy efficiency is the ratio of how much energy is used to do useful work versus how much is lost or wasted to the environment [5]. When solar cells were first invented in the 1800s, they were less than 1% efficient [6]. In 1992, the most efficient PV cell could reach a maximum of only 15.89% efficiency. Now, commercially available PV cells are over 20% efficient [7], however, in 2017 a group of American scientists  created a prototype for a 44.5% efficient solar cell in 2017. 

Improvements in efficiency resulted in the price of solar energy rapidly declining.  

Over the past 40 years alone, refining solar technology has produced a 99% decline in the cost of solar energy (particularly solar PV modules) [8].  

Solar in the U.S. cost about $76 per watt in 1977, and decreased to about $0.25 per watt in 2017 [9]. 

Canadian Usage

Canadian usage does not reflect the environmental merits and cost of solar energy. 

Demand for solar energy is still new, primarily because of the relatively acute environmental movement. In addition, national grid infrastructure for distributing energy across the country is massive, and upgrading them to better accommodate for solar energy is expensive and slow [11]. This creates latency between demand and use.

Despite the improved efficiency of solar energy, a solar energy station’s capacity is still much less than other forms of non-renewable energy. For example, the efficiency of a coal power station ranges from 70-80% capacity. This makes solar energy in comparison economically less attractive [11]. 

Lastly, intermittent daytime sunlights equals intermittant power. Solar energy is storable, but costly [11]. This makes solar energy better as an  additional energy supply to the grid, but not as the main supply to the grid due to its intermittency. 

However, as the declining cost of solar (and other renewables) creates a focus on improving energy storage technologies to make it cheaper [12],  the intermittent nature of solar power will be better managed. 

Solar energy use is modestly increasing in Canada

Despite the current barriers that prevent solar from providing more of the world’s energy supply, the use of solar is on an upward trend. 

Over the past 10 years, solar electricity has grown about 50% globally [13]. This makes solar energy the fastest growing electricity source in the world [14].

In Canada, we have invested $4.4 billion in developing solar energy technology and increasing its capacity on the grid between 2014 to 2018  [15].  

Consider Ontario, where there has been an increase in solar electricity production from virtually zero to almost 2 GW in 10 years. There is evidence that solar energy is growing quickly in local and global markets[13]. 

With environmental motivation and overall cost reduction, the future of solar power is a bright one. 

References

[1] Energy.gov, “Top 6 Things You Didn’t Know About Solar Energy,” Department of Energy, 2016 6 June. [Online]. Available: https://www.energy.gov/articles/top-6-things-you-didnt-know-about-solar-energy#:~:text=Solar%20energy%20is%20the%20most,the%20world’s%20total%20energy%20use.

[2] NW Wind & Solar, “How do solar systems produce energy?,” NW Wind & Solar, 2015. [Online]. Available: https://www.nwwindandsolar.com/solar-power-in-seattle-and-the-northwest/how-do-solar-systems-produce-energy/#:~:text=Solar%2Dpowered%20photovoltaic%20(PV),to%20your%20home%20or%20business.)..

[3] A. Lehner, “Solar PV,” Student Energy, [Online]. Available: https://www.studentenergy.org/topics/solar-pv.

[4] S. Hymel, “Alternating Current (AC) vs. Direct Current (DC),” SparkFun Electronics, [Online]. Available: https://learn.sparkfun.com/tutorials/alternating-current-ac-vs-direct-current-dc/all.

[5] A. Dusto, “Efficiency (Physics): Definition, Formula & Examples,” Sciencing , 5 December 2019. [Online]. Available: https://sciencing.com/efficiency-physics-definition-formula-examples-13722775.html.

[6] S. Matasci, “How solar panel cost and efficiency have changed over time,” energysage, 4 July 2019. [Online]. Available: https://news.energysage.com/solar-panel-efficiency-cost-over-time/.

[7] V. Aggarwal, “What are the most efficient solar panels on the market? Solar panel cell efficiency explained,” energysage, 22 January 2020. [Online]. Available: https://news.energysage.com/what-are-the-most-efficient-solar-panels-on-the-market/.

[8] R. Allessandra, “The Falling Cost of Solar Energy: Reasons and Implications,” Solar Feeds, 21 August 2019. [Online]. Available: https://solarfeeds.com/falling-cost-of-solar-energy-reasons-and-implications/.

[9] B. Nussey, “Why does the cost of renewable energy continue to get cheaper?,” Freeing Energy, 10 March 2019. [Online]. Available: https://www.freeingenergy.com/why-does-the-cost-of-renewable-energy-continue-to-get-cheaper-and-cheaper/.

[10] National Energy Board of Canada, “CANADA’S RENEWABLE POWER LANDSCAPE: Energy Market Analysis 2017,” 2017. [Online]. Available: https://www.cer-rec.gc.ca/nrg/sttstc/lctrct/rprt/2017cndrnwblpwr/2017cndrnwblpwr-eng.pdf.

[11] K. Mathiesen, “What is holding back the growth of solar power?,” The Guardian, 31 January 2016. [Online]. Available: https://www.theguardian.com/sustainable-business/2016/jan/31/solar-power-what-is-holding-back-growth-clean-energy.

[12] W. Hicks, “Declining Renewable Costs Drive Focus on Energy Storage,” The National Renewable Energy Laboratory, 2 January 2020. [Online]. Available: https://www.nrel.gov/news/features/2020/declining-renewable-costs-drive-focus-on-energy-storage.html.

[13] Canadian Solar Industries Association, “Roadmap 2020: Powering Canada’s Future With Solar Energy,” [Online]. Available: https://www.cansia.ca/uploads/7/2/5/1/72513707/cansia_roadmap_2020_final.pdf.

[14] Center For Climate And Energy Solutions, “Renewable Energy,” Center For Climate And Energy Solutions, [Online]. Available: https://www.c2es.org/content/renewable-energy/#:~:text=Solar%20photovoltaics%20are%20the%20fastest,percent%20of%20the%20world’s%20electricity.

[15] Natural Resources Canada, “Energy and the economy,” Natural Resources Canada, 26 May 2020. [Online]. Available: https://www.nrcan.gc.ca/science-data/data-analysis/energy-data-analysis/energy-and-economy/20062.