A Bright History

Photovoltaic solar panels have been around since they were first effectively producing a current in Bell Laboratories in 1953, but the discovery leading to them came much earlier. In 1876 it was discovered that some materials could produce and conduct an electrical current just through exposure to sunlight.

Fast forward 100 years after this discovery to the 1970s and PV solar arrays were being used to power satellites in space. However, their presence on the ground was still lacking. It was too expensive and space consuming to be worth installing solar power for most applications, but research supported by academia and the government has helped us come to where we are today.


What’s the Difference?

While many alternative energy companies purchase their panels from Asia, Rocknoll Energy sources their panels from the United States.
The facilities use advanced equipment with extensive quality control and tracking techniques that ensure the quality of the solar panels. Rocknoll Energy only installs A rated cell panels to ensure long life in addition to minimal degradation.

When you select Rocknoll, you keep jobs in America.

Careful calculations are needed to determine what type of solar installation is needed and how many PV panels are required. Rocknoll can assist you in defining your needs and determining a viable Return on Investment (ROI) period. Typically it’s in the range of 6 to 8 years.

For information on incentives such as the 30% Investment Tax Credit (ITC) for solar, and grants, head over to our Incentives page.



Solar Panel Options:

Where will it go? How does it work? What if the sun doesn’t shine?


When looking at installing solar panels to power your home or business, there are a lot of variables that can come into play. Everyone’s needs are different, but all systems will fall into one of two main categories.


Grid-Tied Solar Panels:

In grid-tied systems, think of the grid as your storage bank. Any power you make and do not use right away will be sent away along the power lines. This is recorded by the utility company for future reference. Then at night, or a cloudy day when your solar panels are not producing enough to power your needs, you draw back from the grid. How the utility compensates you for your contributions differs from company to company, however, in order for there to be grid connection, an interconnect agreement must be submitted.

** One note to be made about grid-tied systems is that the solar system will shut off if the grid goes down. The way things have to be wired, if you were to lose power from the grid, it forces the PV collectors into shutdown as well. It’s a common misconception that we wanted to address here.


Grid Independent Solar Panels:

Truly “off-grid” systems require a battery bank to store up excess energy so that it can be redistributed later. Sometimes a fossil fuel generator is also paired with the system for a backup power source. In some more rural areas, this could be more reliable option than the grid. Due to the batteries, these systems tend to be more expensive than a grid-tied system of the same size. However, fundamentally these systems work the same way something tied to the grid would be.


Separate from how you choose to connect and use the power generated by your solar array, there are several mounting options.


Fixed Roof Mount:





Perhaps the most thought of form of mounting when residential solar panels are thought of, arrays can be affixed to pitched or flat roofs. Solar panels are ideally faced due south and at an angle between 25 and 45 degrees from horizontal. Due to these parameters, in some cases, the desired roof location is not in an ideal orientation and isn’t a viable option.


Fixed Ground Mount:







Using metal posts, a rack system is being constructed at ground level to support solar panels much like how they would be on a roof. The array can be planned in an ideal orientation instead of relying on a pre-existing building. Depending on the size of the project, the rack could be one long array or several “rows” of arrays. This method is best for larger projects, or homeowners with plenty of land to hold their energy generation.


Fixed & Adjustable Pole Mount:






This method is great for smaller projects or uneven terrain. Unlike the previous two methods, there is a variable angle mount option that Rocknoll can provide. With a hand crank on the back, the angle of the panels can be adjusted as the season’s change to optimize power production. However, this is a more expensive option looking at price per panel mounted. The pole used to support the array has to be much larger than those used to build the roof and ground mounted systems, causing the price to rise.


There are several other types of mounting solar panels that Rocknoll does not yet support, such as tracking mounts. These other forms of mounting can be more efficient as they follow the sun to get more direct contact, however, they haven’t been improved enough to make cost-efficient in many cases.



Science behind Solar

Each solar panel generates DC electricity when exposed to the sun. The appliances and fixtures in any home, commercial, or industrial building are going to need electricity in the AC form. An exception to this rule would be if you were to buy specially made appliances for off-grid homes that have been engineered to run on DC.

This DC power can be used in one of two ways. It will either be stored away in batteries, or run through an inverter where it is transformed into AC your home or business can use. If the system has batteries, upon discharge the DC signal will still have to be converted by an inverter.

If the system is grid-tied, after any current power needs are met by the solar array, any excess electricity will get sent through a bidirectional net meter out onto the grid. The utility provider will keep track of what you put out onto the grid and what you take when the solar array is not generating, only billing you for your net use. If you put out onto the grid more than you use, then you can be given a credit.


Want to know more about how a Solar Photovoltaic System works? Head on over to the Department of Energy’s Office of Solar Technologies: DOE