Commercial solar pv system and industrial solar system

Solar photovoltaic (PV) systems, also referred to as solar electric systems, capture sunlight energy and convert it into electricity. PV systems can be used to power everything in your home from lights and appliances to an electric vehicle.

How Does PV Work?

1.Individual photovoltaic (PV) cells are embedded onto panels. Sunlight striking the panels is chemically converted into direct current (DC) electricity.

2.The DC electricity goes to an inverter that transforms it into alternating current (AC) for household use.

3.The utility meter records the net amount of energy (kWh) consumed. When the system creates more electricity than needed in the home, the meter will "spin backward" and the excess electricity is released onto the electric grid and 'credited' to your utility account. These credits help offset the cost of kWh usage at night or on cloudy days when PV systems are not producing as much electricity.

How can I compare PV panels?

PV panels can be evaluated by cost, efficiency and power capacity. Typically the higher the power rating and efficiency, the higher the panel cost. Discuss with your contractor about the expected performance of each type of panel to understand if the kWh production from a higher efficiency rating may offset the higher cost of the panel.

For more information on evaluating PV panels visit the EnergySage Solar Marketplace.

How do I choose an inverter?

There are two types of inverters: central and micro.

Central inverters – One individual inverter per array. This is the classic technology that is installed with most solar systems. The kW size of these inverters is determined by the total number of panels linked to it. Therefore, any plans to increase the system size due to future appliance additions, should be considered during the initial stages of design. While the main drawback of central inverters is performance limitations, such as shading tolerance, this can be improved with the installation of power optimizers.

Microinverters – One individual inverter per panel. Microinverters allow overall systems to be more tolerant to shade by allowing electrons to bypass any shaded cells, avoiding a severe drop in total production and allowing for more flexible system placement. They more easily allow for future panel additions by simply adding an additional microinverter for each additional panel.

Individual photovoltaic (PV) cells are embedded onto panels. Sunlight striking the panels is chemically converted into direct current (DC) electricity.

The DC electricity goes to an inverter that transforms it into alternating current (AC) for household use.

The utility meter records the net amount of energy (kWh) consumed. When the system creates more electricity than needed in the home, the meter will "spin backward" and the excess electricity is released onto the electric grid and 'credited' to your utility account. These credits help offset the cost of kWh usage at night or on cloudy days when PV systems are not producing as much electricity.

How can I compare PV panels?

PV panels can be evaluated by cost, efficiency and power capacity. Typically the higher the power rating and efficiency, the higher the panel cost. Discuss with your contractor about the expected performance of each type of panel to understand if the kWh production from a higher efficiency rating may offset the higher cost of the panel.

For more information on evaluating PV panels visit the EnergySage Solar Marketplace.

How much does a typical commercial solar PV system cost?

A number of factors determine the final price of a PV system, including its size, component options and configuration, labor costs, local permitting costs and available incentives and tax credits. 

The cost of a solar electric system is measured in dollars per watt. The average cost for a commercial system is currently $2-4 per watt. That means a 20-kW commercial system will cost $40,000-$80,000, prior to tax credits or incentives.

Contractors are your key resource to getting the most appropriate solar system for your individual budget and property needs. Contractors typically provide free site evaluations as well as comprehensive quotes, system specifications and payback information.

Selecting a contractor

We recommends contacting and evaluating at least three contractors and their bids before selecting one to install your system. Consider the following tips and best practices.

Tips and best practices for hiring a contractor

Seek multiple bids - We recommend that you obtain at least three bids from different contractors. Use CSE's bid comparison worksheet to help you compare contractor proposals.

Get References - It's a good idea to request references from previous customers. You also may want to consult third-party review resources such as the Better Business Bureau or Yelp before making a selection. 

Hire only a licensed contractor - Ask for the company’s state contractor license number and check your state licensing board to ensure that your contractor and subcontractors are licensed and in good standing. The National Association of State Contractors Licensing Agencies (NASCLA) offers links to licensing information throughout the United States.

Never sign a contract under pressure - Insist on at least 48 hours to study any contract.

Pay as you go - Never pay more than 10% down or $1,000, whichever is less, to start a job. Hold back 10% on the final payment until the entire job is complete and has been inspected by the proper authorities. Never pay for work before it is completed.

Never pay cash - Pay by check or credit card.

Get references - It's a good idea to obtain references from the contractor's previous customers. You may also want to consult third-party review resources such as the Better Business Bureau or Yelp before making a final selection.

Hire insured contractors - Always insist upon a certificate of insurance for general liability insurance. Uninsured workers who are injured on the job may file damage claims against the business owner.

Get a thorough written contract before any work begins - Any work valued over $500 requires a contract. In the contract, be sure to specify the start and completion dates of the job and insist on a progressive payment schedule specifying exact costs. Be sure to require that all change orders must be in writing.

Keep a job file - Put receipts, permits, plans and anything else pertaining to your job in the file.