How solar panel cost and efficiency has changed over time
Solar panels have been around for more than 60 years. Since then, the technology has improved, while the cost of solar panel installation has decreased.
The payback for a residential solar panel system for an average home in Canada during the early 1970s was 210 years. Today, this payback is between 10 to 15 years, on average–depending on system size and production capacity.
While the cost of these solar panels has decreased over time, the efficiency of the photovoltaic technology used has increased, substantially.
What is solar photovoltaic technology?
Solar photovoltaic technology is the conversion of sunlight into electrical energy by photovoltaic materials, such as solar cells. Solar cells are individual electricity-producing silicon based semiconductor materials with varied shapes and sizes–from miniature to several inches across.
These cells work to convert energy from the sun into energy forms we can use by directly absorbing photons—light particles that act as individual units of energy—and converting this energy to electricity.
To protect the solar cells, which are less than the thickness of four human hairs, from different environmental stressors that exist, they are sandwiched between protective materials in a combination of glass and plastics to make a solar panel.
How have solar panels changed over time?
The very first solar cells back in the 1800s were (less than) one percent efficient–not nearly enough to make them a useful energy source. Bell Labs invented the first useful solar cell in 1954, more than 60 years ago—with an efficiency of about six percent.
Since then, scientists have improved on the technology tremendously.
In the early 2000s, the solar industry was forever changed when manufacturers reported that they could create solar panels that were 30 percent efficient. Today, researchers have achieved an efficiency of more than 46 percent using advanced cell structures.
In addition to the dramatic increase in solar panel efficiency, solar panel manufacturers have significantly improved their production processes to integrate the most recent developments efficiently and inexpensively in the manufacturing processes.
A good example is an improvement in the manufacturing process for solar cells incorporated into solar panels. By covering the entire backside of the silicon wafer, equipping the solar cells with a wide-surface metallic contact allows for efficient electricity to flow from the cell to the electrode.
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Solar panels and your home
For residential homes located in the northern hemisphere, Canada for example, solar panels are best installed on rooftops that are south-facing in an arrangement commonly referred to as an array.
For example, solar panels that produce 250 watts are installed in an array of 20 panels to create a 5-kilowatt-hour solar panel system. The array is connected to an inverter, located within the home.
This inverter controls the flow of electricity to the home’s circuit breaker. Then through a special meter to the utility company responsible for crediting the household if excess power is generated.
This is called “net-metering” which we will discuss in a separate article.
Residential solar energy systems are typically 5-kilowatts to 10-kilowatts, with the size dependent on household use, rooftop space, and sun orientation–among other factors.
For perspective, one kilowatt is 1,000 watts. One kilowatt hour (kWh) is a measure of electricity demand per hour by a homeowner. So a one-kilowatt hour is the energy expended by fifty 20-watt compact fluorescent lights burning for one hour.
The average Canadian home—in Ontario—uses about 1,000-kilowatt hours of electricity per month.
What’s next for solar panel technology?
The transformation of energy production towards the goal of incorporating more electricity from renewable sources such as solar energy is one of the biggest challenges that our society will face in the coming decades. Solar panel technology will play a decisive role in reaching that goal.
The price decreases of solar panels over the past ten years is a primary reason some homeowners are becoming increasingly interested in installing solar panels. Plus, a growing interest in renewable energy technology and positive change towards fighting climate change have promoted its global adoption.
Solar panel technology has improved, while system cost has decreased over the years. Rebate programs such as the Ontario microFIT, net-metering, and other government incentives have made solar power affordable for many homeowners in Canada.
Our expert Solar Brokers can help you understand if solar is right for you, if your roof qualifies, and recommend a system that suits your specific needs.