Frequently Asked Questions about PV Systems

Questions

• How does solar electric system work?
• What is a PV module?
• What is inverter and what it does?
• What is net metering?
• What do the terms on-grid, grid-connected, grid-tied and off-grid solar systems mean?
• How much roof space do I need to power my household?
• What happens to the solar electricity I don’t use?
• Do I need batteries?
• Will my system work on cloudy days?
• What happens during the power outage?
• Can I be totally independent from the utility?
• What direction should the solar system face?
• What if the system cannot be put on my roof?
• How long will my solar system last?
• What maintenance the solar system requires and how much it costs?
• How many solar panels do I need to power my house?
• How much power will a system produce?
• Will the solar system produce enough energy to cover my electric bills?
• Is solar electricity cost-effective?
• What is solar thermal?
• How long does it take to install a solar electric system?
• Do I need a building permit to install a PV system?
• Do I need permission from the utility company to connect my solar system to the grid?
• How can I finance residential/commercial solar system?
• What rebates and incentives are currently available in Hawaii?

Answers

Question: How does solar electric system work?
Answer: When sunlight strikes the solar cells in the module, electrons are released from solar cells’ silicon semiconductors. These flowing electrons create DC power (direct current) which is converted by an inverter to AC power (alternating current) used in our households. There are grid-tie and off-grid solar electric system available at the market. Your grid-tie system is connected with your utility. When your solar system produces more electricity that your household needs, your utility company offers you net metering agreement that credits you account for the electricity that is returned to the grid. Your utility company provides you with the electricity when your system is not producing electricity. Off-grid systems are not connected to any utility grid. They have a battery backup and optional backup generator which allows your solar system to store electricity to be used when there is no sun.

Question: What is a PV module?
Answer: Photovoltaic (PV) module is a packaged interconnected assembly of photovoltaic cells. Photovoltaic cells are commonly known as solar cells, and PV modules are commonly known as solar panels. Most solar cells are made of semi-conducting materials usually crystalline silicon cells or thin-film cells (cadmium telluride or silicon).

Question: What is an inverter and what it does?
Answer: An inverter is an electrical device that converts DC (direct current) power produced by solar cells into AC (alternating current) power. We need AC power to operate our household equipment and appliances.

Question: What is net metering?
Answer: Net metering is a service provided by a utility company. It measures the difference between the electricity you buy from the electric company and the electricity that is produced by your solar system. If you produce more electricity your household uses, the excess of electricity goes back to the utility grid and your meter spins backwards. The meter spins forward when you solar system does not supply all the electricity you need (for example at nights). The meter keeps track on the net differences and you save money on your electric bills.

Question: What do the terms on-grid, grid-connected, grid-tied and off-grid solar systems mean?
Answer: On-grid, grid-connected and grid-tied means the systems are connected to the utility grid. Off-grid systems are not connected to the utility electrical grid. They must to be custom designed to meet particular needs of the client. Islandwide Solar offers grid-tied, off-grid and hybrid systems.

Question: How much roof space do I need to power my household?
Answer: To estimate how much space of the roof is needed to power your household we will do a little math. About 100 sq. ft. is needed for every kilowatt (kW) of electricity. An average size solar electric system will need approximately 300-500 sq. ft.

Question: What happens to the solar electricity I don’t use?
Answer: If you are grid connected, net metering allows you to deliver any excess of electricity produced by your solar system back to their grid. In this case, your meter goes backwards and you save money on your electrical bills.

Question: Do I need batteries?
Answer: You do not need batteries if you are connected to the utility grid; the utility company will be your power backup. You definitely need batteries if you consider purchasing off-grid system or you need power during blackouts.

Question: Will my system work on cloudy days?
Answer: The solar electrical system cannot produce electricity without direct or diffused sunlight. When the sky is overcastted, your system will produce substantially less electricity.

Question: What happens during the power outage?
Answer: When the electricity power from your utility company goes out, grid-tied solar electric inverter will be shut down by the NEC 1741 electrical code requirement. Only off-grid systems or systems with batteries and/or generator will produce energy during power outage.

Question: Can I be totally independent from the utility?
Answer: Yes, to be totally independent from the utility company, you need to consider buying off-grid system. They must be custom designed to meet your personal needs.

Question: What direction should the solar system face?
Answer: Usually the best direction for the solar panels array location is south. But in many cases southeast and southwest facing systems may produce more than 90% of optimum power production.

Question: What if the system cannot be put on my roof?
Answer: There are many other solutions such as ground mount, trellis, pergola or car port solar application.

Question: How long will my solar system last?
Answer: Most solar modules manufacturers provide warranty for 25 years power output. They are very durable and may have a longer lifespan. Only the batteries will need a replacement in 5-10 years. Inverters are typically under warranty for 10 or 15 years then 5 years for off grid installations.

Question: What maintenance the solar system requires and how much it costs?
Answer: Solar photovoltaic systems typically require little or no maintenance for many years. Please consult with your sales manager about Islandwide Solar maintenance package.

Question: How many solar panels do I need to power my house?
Answer: The solar system size depends on your average power usage, climate, shading problem and other factors. Another big factor is whether you are connected to the utility grid or your system is off-grid.

Question: How much power will a system produce?
Answer: The amount of power produced by a solar system may vary on a daily basis and depends on the size of the system, your geographic location, climate, shading problem, module orientation and a battery backup.

Question: Will the solar system produce enough energy to cover my electric bills?
Answer: It depends on the system size. A small system can reduce your electric bill by 25-50%. It is the most cost-efficient approach for residential solar power. Of course, you can install a photovoltaic system that will produce as much electricity you need and even more to reduce your bill to zero.

Question: Is solar electricity cost-effective?
Answer: Yes, a solar electric system is a great high-return investment. Moreover, a solar electric system increases the value of your property.

Question: What is solar thermal?
Answer: Solar thermal is a solar water heater. Solar thermal installations are different that photovoltaic installation. They involve solar collectors on the roof filled with a liquid or water which runs through the piping system. The liquid or water is heated by the sun.

Question: How long does it take to install a solar electric system?
Answer: Islandwide Solar usually installs a solar electric system in 2-3 days. However the entire process to include design, permitting, equipment delivery, inspections takes approximately 4 to 6 weeks.

Question: Do I need a building permit to install a PV system?
Answer: Yes, Islandwide Solar obtain the necessary permits for you.

Question: Do I need permission from the utility company to connect my solar system to the grid?
Answer: Yes, there are rules that must be followed to a solar system to the grid legally. The rules are based on national standards with which solar systems have to comply. Islandwide Solar helps you with all documentation and procedures. There is no permission needed for off grid systems.

Question: How can I finance residential/commercial solar system?
Answer: With the EnerBank USA, which products are only available through authorized and participating dealers, you’ll get:
No payments and no interest for 12 months on approved credit, 100% unsecured financing from $1,000 to $45,000 on approved credit, quick, easy, and safe toll-free loan-by-phone application process, fast credit decision in about 10 minutes, No paperwork, Peace-of mind because you provide your personal financial information directly to the bank and not to your dealer or over the internet

Question: How can I finance residential/commercial solar system?
Answer: For photovoltaic systems, the maximum allowable credits are as follows:

• Single family residential property is eligible for a credit of 35% of the actual cost or $5,000, whichever is less.
• Multi-family residential property is eligible for a credit of 35% of the actual cost or $350 per unit, whichever is less.
• Commercial property is eligible for a credit of 35% of the actual cost or $500,000, whichever is less.

Have a question we didn’t answer here, please will free to email us at info@sunnyliving.com