How Does Rooftop Solar Work

With the price of solar energy dropping and the efficiency of rooftop solar panels increasing, it is an excellent time to look at how rooftop solar works. With the promise of cheap, clean energy sources, solar energy seems like a natural choice. However, there are issues you need to consider before investing in solar power for your home.

How Does Rooftop Solar WorkPin
How Does Rooftop Solar Work

Today we will look at how rooftop solar works, the benefits of solar energy, and the problems you need to consider.


The History of Rooftop Solar

All solar energy systems work by converting sunlight into electricity. The conversion is done by a Photovoltaic Cell, which undergoes a chemical reaction when exposed to sunlight. These PV cells got invented in the 1800s by a French Physicist Edmond Becquerel after he discovered the Photovoltaic effect. However, it was in the 1950s when the new silicon Photovoltaic Cell got created at Bell Labs.

History of Rooftop SolarPin
History of Rooftop Solar

The silicon PV cell is the solar cell we use today for electricity generation.  

How do Solar Panels Work?

Solar panels consist of solar cells, and these are layers of silicon that get sandwiched between a glass casing. One of the layers has a positive charge, and the other has a negative charge.  The surface where the two layers meet produces an electric field.

As the sunlight hits the solar cell, the photons from the sunlight will knock an electron free from the negatively charged layer.  This free electron can not cross the electric field, so it takes the path of the circuit and flows from the negative to the positive layer.

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How Solar Panels WorkPin
How Solar Panels Work

Solar equipment provides DC power, so you will require a solar inverter to convert the DC to current (AC) electricity.  A central inverter will optimize the entire solar array.  Recently there has been an industry move to micro-inverters that are attached to each solar module to increase efficiency. 

Technology enhancements have delivered significant improvements to solar panel efficiency. Today’s solar panels are up to 22% efficiency, meaning that they convert 22% of the sun’s energy into electricity. With the push for cleaner and renewable energy, this efficiency will keep on going up.

This increase in efficiency has occurred during a time where the cost of solar panels has dramatically decreased. Since the start of the century, the price of panels has dropped almost 75%. Coupled with the increase in energy efficiency, you get a lot more power for your dollar.

What is the Downside of Rooftop Solar

With all the benefits of solar energy, it is useful to look at the downsides of solar panels.  

You need roof space that is facing towards the sun. In the Northern Hemisphere, this means a south-facing roof.  The size of your roof will determine the number of solar panels you can install. More panels will mean solar electricity you can produce.

For solar panels to work efficiently, you need access to direct sunlight. Any shadow from trees or other buildings will adversely affect electricity generation.

What is the Downside of SolarPin
What is the Downside of Solar

The panels only work when there is sunlight. At night they will not generate any electric current at all.  Bad weather will also adversely affect generating electricity.  So if you live in an area with a lot of rainfall, then your energy production will be limited.

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Like all electricity generating systems, rooftop solar power needs to gets consumed as soon as it gets produced. The addition of batteries gets used to store the excess energy for later use.

A recent advance in rooftop solar systems it the grid-connected system.

What is a Grid-Connected Solar System?

A grid-connected system connects your rooftop solar system to the regular electrical grid. You get the best of both worlds as you use your solar energy when your panels are in sunlight and standard grid power when needed.

You will even supply energy to the power grid when you produce more energy than you are using. Providing excess electricity to the network will give you energy credits towards your electric bill and ensure your solar panels are not producing wasted power.

The ability to provide energy to the electric grid is ideal, as most solar systems will produce excess energy during daylight hours. 

For a grid-connected system, you will need to talk to your local electric utility company.  You will also need to check if there are any state incentives for solar adoption in your area.

More Questions 

  1. How much power can I generate if I install solar?  There are a lot of variables, but there is a tool called PVWatts that will give you an estimate.  This estimate is an excellent place to start. However, you should contact a solar installer to get a more accurate estimate.
  2. Will you save money with solar?  The amount of money you can save on your electricity bill depends on several factors.  The primary factor is the current electricity rates you are paying and how much the utility will give you for your excess electricity production.  
  3. Will installing solar increase the value of my home?  All houses are different, but the addition of solar to a home is just like any other home improvement.  According to, the addition of solar can increase the value of a home by up to $15,000.
  4. Can I get tax breaks or other incentives?  Incentives tend to be different depending on where you live.  You can visit DSIRE and enter your zip code to find out what incentives are available in your area.  Local solar companies will also be able to help you with the available tax credit and incentives.
  5. Does solar help the environment?  As solar is a clean and renewable form of energy production, it helps reduce our reliance on fossil fuels.  The move to renewable energy will continue.
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Using solar cells to generate your electric current is not only good for the environment but will also reduce your utility bills. The solar industry is growing, and the number of solar options ins increasing.  Now is a great time to explore whether rooftop solar is the right option for you.