How Solar Works

a guest post by Bob Haughton, Vice President of Business Development at ONTILITY

While the solar process itself is pretty simple in the basic mechanics, it is the situation application that makes designing and installing solar a challenge.  Different roof configurations, shading concerns, remote location scenarios and many other varia

While speaking in specifics about solar energy and the many different facets of the industry, it’s easy to forget that not everyone reading this blog actually understands how solar works. It is with that thought in mind that made me decide to put together this simple "SOLAR 101" that hopefully explains how the process works in the mechanics of a simple solar array.

Let’s first go over the basic components of a simple grid-tied solar array. The first component is the solar panel itself. Panels are usually wired through a combiner box and that wiring is then sent down to an inverter. The panels are held in place by racking. Those are the four major components to a grid-tied system. Here’s a brief description of those major components.

Solar panels – Panels, either mounted on roofs or on the ground in various fashion, absorb energy from the sun. The radiation from the sun excites atoms in the crystalline cells, which are all wired together in series, which make up a solar module and generate electricity. The electricity generated at this point is direct current (DC) and must be converted to AC to be utilized in the facility.

Inverters – Phase inverters are needed to convert the DC power generated by solar panels into usable AC power. While inverters of many years ago were mostly mechanical in nature, today's inverters are predominantly made up of electronic components that convert DC to AC. Depending on the type of need and output, the options of inverters vary from application to application and can be as small as a loaf of bread or large enough to fill a room.

Racking – Racking can be made of many different materials for many different types of application allowing a virtual endless supply of mounting options for most every situation. While solar racking, normally made up of aluminum components, usually fasten to the existing structure with bolts or screws, ballasted racking allows for the solar array to sit on a structure and be held in place by the weight of ballast blocks with no penetrating fasteners.

Combiner Boxes – Solar arrays are made up of groupings of modules called strings. Multiple strings of panels are wired into a combiner box and then typical electrical cable runs to the inverter for power conversion. The converted power is then fed through a system disconnect and into the facility service panel, where it is utilized by power demands of the building or home or in many cases, where production exceeds demand, it feeds excess power back to the utility power grid. Most utility providers require an Interconnect Agreement in order to not only connect to the grid but also to sell excess power back to the grid.

In a typical grid-tie system, one of the misconceptions that exist is that when grid power goes away, the facility will still have power generated by the solar array. That is not the case. In a true grid-tie scenario, as soon as the inverter senses that the grid is not active, it shuts down and solar production is halted. In order to allow the array to continue to generate when grid power is not available, a secondary power source input to the inverter must be utilized. In most cases, that secondary power source is either a battery bank or a generator. In a scenario where either source is used, a hybrid inverter is utilized that can recognize and secondary power input signal and turn back on so that the array on the roof can continue to produce power and supply electricity to the facility.

While the solar process itself is pretty simple in the basic mechanics, it is the situation application that makes designing and installing solar a challenge. Different roof configurations, shading concerns, remote location scenarios and many other variables make most solar arrays unique and always interesting.

Bob Haughton Bob is responsible for multiple disciplines relating to overall company growth but focuses on leading the large scale national distributor accounts marketing effort as well as leveraging installation/distribution marketing and procurement of large scale projects nationwide. Prior to Ontility, Bob was President of Renewable Energy Resource Associates as well as Regional General Manager over the South Texas/State of Louisiana region for Standard Renewable Energy/Gridpoint. Bob received a BA in Architecture from the University of Houston and is a State of Texas and Nationally certified Registered Building Designer.

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