Frequently Asked Questions (FAQ’s) & Solar Glossary
What does “PV” mean?
“PV”, short for photovoltaic, is the technology that allows sunlight to be converted directly into usable electricity.
How do solar panels work?
A semiconductor material, often silicon, is faced toward the sun. Energy waves in sunlight excite electrons in the silicon initiating an electrical current. Electrical wiring, from your solar panels to your building’s electrical service, serves as the link to deliver the sun’s power.
What is the difference between DC and AC power?
Your solar panel system generates DC power – like the power in flashlight batteries. The DC power from the solar panels is converted to AC power by an inverter. The conversion from DC to AC means a slight loss of energy, roughly 10-15%. This explains why it is important to know whether a system is being quoted in DC or AC.
What is a kilowatt hour, or kWh?
A kWh is the common unit for measuring electricity, similar to the way that a gallon is a unit of measurement for liquids like milk and a pound is a unit for measuring weight. When you use 1000 watts of electricity for one hour it is 1 kWh. 1kWh is the equivalent to using a hair dryer 4 times for 15 minutes or running a small refrigerator for 24 hours.
What is ‘Net Energy Metering’?
Net energy metering is a special billing arrangement between solar PV customers and their local utility that permits the customer to receive credit for the full retail value of the electricity their system generates. When the electricity generated by a solar power system exceeds the energy consumed, the solar PV customer not only eliminates their electricity bill, but can also “sell” the power back to the utility company in the form of credits. Over a 12 month period, the customer has to pay only the amount that was not offset by their solar system.
How does the utility company charge me for electricity? What are tiers?
The utility charges customers per kWh consumed ($/kWh). The cost per kWh increases as more power is consumed during a month. This ‘tiered’ rate structure rewards conservation and penalizes big power consumers. The upper tiers are the most expensive, often double that of the base line rate; solar power offsets the upper tiers first.
What happens to my utility bill?
The utility will continue to mail you a monthly gas and electric bill as usual. Along with this bill, you will also receive statements itemizing your home’s electrical consumption/PV generation. You have the option to pay your electric bill monthly or just once a year.
How does the California state rebate work?
The California state rebate is broken down into two rebate program options called the Expected Performance-Based Buydown (EPBB) and Performance Based Incentive (PBI). Both programs are administered by the California Solar Initiative (CSI). The EPBB rebate is a one-time, up-front incentive based on the expected electrical production of your system and is generally the option taken by homeowners. You will receive the rebate check 1-3 months after the system is complete. The rebate can also be ‘reassigned’ to Green Power Systems so you are only responsible for the net cost of the project. The PBI rebate is typically taken on projects larger than 12 kW and is mandatory for projects over 50 kW. This rebate is paid back to the customer in monthly installments over 5 years and is based on actual production of the solar system. Monitoring systems within 2% tolerance must be used with installations utilizing the PBI rebate to monitor performance. As more homeowners and business owners purchase solar systems, the amount of rebate money available for a project goes down. Time is of the essence to purchase your solar power system today so that you get the highest rebate currently available.
When do I receive the Federal Tax Credit?
For residential customers the one-time 30% Federal Tax Credit is applied to your tax return statement during the year the system was placed into operation. The Green Power Systems Owner’s Manual gives information on the necessary forms and timelines for obtaining the tax credit. However, Green Power Systems does not provide tax advice and we encourage all of our customers to seek the advice of their tax professional on how you can best take advantage of the Federal Tax Credit.
When do I receive the Federal Tax Grant?
Commercial customers may apply to receive a 30% upfront grant towards the cost of the solar system. Applicants will receive grants from the Treasury Department 60 days after request submission. Grants are subject to availability.
Do solar energy systems come with a warranty?
Yes, Green Power Systems provides an industry leading warranty for all of our systems. All of our solar panels come with a 25-year warranty to secure your long term investment. We also offer a full 10-year installation warranty on all parts and labor to add to that security. In addition, Green Power Systems has a 5-year 72-hour onsite guarantee. Should your system ever malfunction, we promise to have a technical support engineer onsite within 72 hours to access your system so that we can bring it back online as soon as possible.
What type of maintenance do solar energy systems require?
The solar panels used in all of our systems require virtually no maintenance except for occasionally cleaning their surfaces with warm water. A periodic wash will prevent dust and debris from building up and will ensure your panels perform optimally year-round.
When does the system pay off?
The payback for residential systems generally takes between 7-9 years. After that, every dollar saved is a dollar earned. Historically, utility rates increase on average 6.7% per year; this means that in 9 years the amount of your electricity bill will double. By installing a solar system, you save money on your electric bill immediately and avoid future inflated utility payments.
How do I know if my house is right for solar?
Coastal and inland roofs alike make great candidates for solar systems with the ideal location being on South and West facing roofs with little to no pitch. New roofs or roofs that are less than 10 years old are suggested for solar installations. Green Power Systems recommends that any shading from large trees or structures is avoided at the proposed location of a solar array
AC Power: This term refers to an alternating electrical current that changes between positive and negative directions. Our utilities use AC power.
DC Power: DC power is electrical current that flows in one direction, either positive or negative. PV modules produce DC power. However, our utilities use AC power, so DC power has to be converted to AC power in order to be useful. An inverter makes this conversion.
Expected Performance Based Buy Down (EPBB): EPBB is a type of incentive structure offered as part of the California Solar Initiative (CSI). The EPBB is used for systems smaller than 50 kWh, which are usually installed on homes and small commercial applications. This structure offers an up-front incentive based on the system’s expected usage. Incentives decline as more solar reservations are made, so time is of the essence. To calculate your potential EPBB incentive, use the on-line calculator at www.csi-epbb.com.
Grid Connected: Grid-connected systems operate in parallel with and are connected to the electric utility grid. All of Green Power Systems’s PV systems are grid-connected, which allows you to reduce or even eliminate your monthly electricity bills without having to change your lifestyle.
Ground Mount: There are various methods of installing a solar system of which ground mounted systems is one. Ground mounted systems are not attached to a home or building, but rather installed using a solar specific structure that supports the solar panels. Ground mounts are ideal for customers with inadequate roof space.
Heat Exchanger: A component of a Solar Hot Water installation used to transfer heat from the solar fluid to the home or building’s water supply. Heat exchangers are double walled and can be built into or be separate from the existing hot water heating tank.
Inverter: An inverter is a device that converts power from the sun, DC power, to power that can be used in your home and business, AC power. An inverter is used in every solar PV installation.
Kilowatt (kW): A measure of power equivalent to 1,000 watts or the power required to run ten 100 watt light bulbs in any instant.
Kilowatt Hour (kWh): A common unit of electrical consumption measured by the total energy created by one kilowatt in one hour. A 100 watt light bulb burning for 10 hours uses one kilowatt hour. To determine the size of the solar system you’ll need, we’ll look at your electricity bills to see how many kWhs you typically use and will need in the future.
LEED: Developed by the U.S. Green Building Council, the Leadership in Environmental and Energy Design (LEED) Green Building Rating System provides a suite of standards for environmentally sustainable construction. It is the nationally accepted benchmark that provides building owners and operators with the tools they need to have an immediate and measureable impact on their building’s green performance.
Megawatt: A measure of power equivalent to one million watts.
NABCEP: The North American Board of Certified Energy Practitioners is a national program that awards professional certification to photovoltaic installers. NABCEP’s high standards are designed to protect customers and enhance the profession. In choosing Green Power Systems, you’re choosing a solar installer that is NABCEP certified.
Net Metering: A policy under which a solar system owner can buy and sell electricity to the utility company through credits. When the electricity generated by a solar system exceeds the energy consumed, the consumer not only eliminates their electricity bill, but can also sell the power back to utility company in the form of credits.
Performance Based Incentives (PBI): PBI is a type of incentive structure offered as part of the California Solar Initiative (CSI). The PBI structure is used for systems greater than 50 kWh and offers a flat rate per kWh. Incentives decline as more solar reservations are made, so now is the time to go solar.
Photovoltaic: Photovoltaics, or PV as you’ll often see it, is a solar energy technology that uses unique properties of semiconductors to directly convert solar radiation into energy. When PV cells, or solar cells, are combined into larger systems called modules, they produce energy with no moving parts, noise, or pollution.
Power Purchase Agreements (PPAs): PPAs are long-term contracts between the customer and the developer where the developer retains ownership of the system and sells the kWhs to the customer at a specified rate for a specified amount of time. Essentially, the customer leases the solar system from the developer. PPAs have been standard throughout the power industry but are relatively new to the solar industry.
Roof Mount: The most common installation technique for solar, in which the solar system is attached to the roof of your home or building.
Solar Collectors: The key component of Solar Hot Water systems that collect the sun’s energy, transform its radiation into heat, then transfer that heat to the solar fluid. The heat is then transferred from the collectors to the heat exchanger, located near the hot water heater. Solar Collectors are made of a weatherproofed box comprised of a glass cover and an aluminum frame.
Solar Hot Water: A technology that uses solar collectors containing solar fluid to transfer the warmth from the sun to heat water for your home, commercial or municipal building. A Solar Hot Water system can provide your home or business with up to 60% of its hot water needs. Solar Hot Water systems can be roof or ground mounted depending on the customer’s needs.
Solar Fluid: Solar Hot Water collectors are filled with solar fluid; the fluid is pumped from the collector to the heat exchanger. The fluid passes through the exchanger to heat the water in your water heater and then is pumped back up to the collector to be re-heated.
Solar Panel: A group of solar PV cells combined into a larger system to produce electrical power.
Utility Grid: Your utility’s network that delivers electricity to your home and business.