How does a solar system generate electricity?
A PV system turns sunlight energy into direct electric energy. Electrons freed by the interaction of sunlight with semiconductor materials in the PV cells are captured in a direct electric current. That electric charge is converted to an alternating current, (the current used in your home or business) by an inverter, either attached to each pv module or at the end of a series of modules. Read more at both The Infinite Power of Texas or The US Department of Energy.
What conditions are necessary?
The solar array must have a reasonable amount of non-shaded, unobstructed space, either for a roof, ground or pole mounted system, during the key sun hours of the day. A southern exposure is ideal, but east and west facing roofs can capture over 80% of the power of a south- facing roof.
Will a solar system produce enough energy to handle all my electric needs?
You will have to determine how much energy you use and how much of an investment you want to make. Look at your electric bill and determine how many kilowatt hours you use over a year’s time and on average for a month. Most homeowners and businesses install a system on the roof with adequate sun exposure that produces between 10%-40% of their needs. In some circumstances, a system may be installed also on the ground or on a pole mount. Any installation of solar should be preceded by energy efficient upgrades to the building or if new construction, built to promote energy savings. Energy not used is energy you need not buy, either in electricity from the grid or from a solar panel.
How much electricity will my solar energy system produce?
The amount generated will depend on the size of the system you install, orientation of the system and shading. Typically a solar energy system using 100 square feet of solar panels will generate 1,000 -1,440 kWh per year.
Your inverter display will show you how much power is produced at any given time. Solar energy systems with miro-inverters, an increasingly popular alternative, allow you to see how your system is performing on a module to module basis.
What happens during an electric outage if my system is tied to the grid?
Grid connected solar energy systems will immediately shut down to protect your electric provider’s linemen.
How durable is a solar energy system?
Systems must pass a standard set of tests and are built to withstand winds up to 125 mph and 1-inch sized hail. To meet these standards, the racking system and solar panels must be installed to the manufacturer’s specifications. Racking systems but be bolted to rafters, not decking.
May I add battery backup at a later date?
Yes, though if you start with some battery backup, it is easier to add more than starting with none. If you start without a backup battery, it will be rather expensive to add batteries, due to the high cost of adding a different type of inverter.
If I live in a neighborhood with a homeowner’s association, will I need their approval?
HB-362 passed in the 82nd Legislative session, limits HOAs and POAs from restricting solar devices outright. The following is a synopsis from the Texas Renewable Energy Industries Association.
POAs and HOAs cannot withhold approval for the installation of a solar device on a roof or in a yard or patio as long as the installation:
•Is installed no higher than the roofline
•Conforms to the slope of the roof and has a top edge that runs parallel to the roofline
•Has solar panel frames that are silver, bronze, or black color tones (commonly available colors in the marketplace)
•Is no taller than the fence line if installed in a yard or patio as ground or pole mounted
How long will installation take?
It will typically take two to three days for a professional installation for a home. For commercial installations, consult your solar installer.
OPERATION PERFORMANCE and QUALITY
What happens at night?
Nothing unless you have a battery backup. The solar panels must be exposed to sunlight to produce energy, but batteries can store that energy.
What happens on cloudy days?
The bulk of your electricity production will take place under sunny conditions. Output is directly proportional to the amount of sunlight available at any given moment. A system can generate 50 - 70% of its typical output under bright overcast conditions, but production will continue to diminish as less light reaches the system.
Is temperature important?
Solar energy systems typically operate in temperatures ranging from -13 to 122 degrees Fahrenheit. Though output drops as the system gets hotter in the summer, the increased daylight hours ultimately increases energy production.
Is the solar energy system warrantied?
Solar energy system modules typically carry 20-30 year warranties. The racking system and inverters should also carry warranties. Be advised that for warranties to apply, these components must be installed to manufacturers’ specifications. Make sure that your installer provides a warranty on installation services.
If this is a grid tied system, does the electricity produced by the system go directly to my house or to the electric provider?
All the energy produced by your solar system flows to your house if all the energy being produced is needed. But sometimes only some of the energy is needed (you are at work, the AC, washer, dryer , ect.) and the excess electricity from the solar array will flow to the electric provider. This is a simplified version of the fluctuating path of the energy produced.
What is net metering?
If your solar energy system is grid tied to your electric provider and it produces more power at any given moment than the property consumes, the extra power will flow to the electric provider. Over any month when a solar energy system sends more power into the electric grid than the homes takes from the grid, the difference or net, will result in a credit determined by the electric provider .Net metering “credits” can be as little as the base rate the utility pays for wholesale power or as generous as the retail rate you pay as a customer. Currently, not all electric providers offer net metering. Contact you electric provider (or providers if you live in a deregulated area of Texas) to determine if this is available..
What are the incentives available for homeowners installing a solar energy system?
The most up to date information on federal, state and local incentives is found at http://www.dsireusa.org/
Federal: Homeowners are eligible for a 30% tax credit on the final cost of a solar energy system, after any state or local incentives.
State: There are currently no state incentives for homeowners who have installed a solar energy system
Local: Homewoners should check with their electric provider to see if incentives are available.
Incentives for businesses? Businesses also have federal tax credits and may have incentives available from their electric provider. The state allows a corporation or other entity subject the state franchise tax to deduct the cost of a solar energy device from the franchise tax. Entities are permitted to deduct 10% of the amortized cost of the system from their apportioned margin. Again, we recommend http://www.dsireusa.org
What size system should I get?
The size you choose is a trade off between the amount of money you wish to invest and the amount of electricity you want to produce. Look at past electric bills, consider the energy efficiency of your property and whether upgrades are needed to cut useage first. Remember you may not cover all your energy needs with a solar energy system. The only other condition in deciding proper system size is the amount of suitable space available on your roof. To be suitable, you must have unobstructed, non-shaded roof area, either flat or a sloped, at an orientation other than North. You need roughly 120 square feet of roof space for each kW that you wish to produce.
How much does a solar pv system cost?
The total cost for purchasing and installing a solar energy system is based on the size of system you require and the specific details of the layout of your property. The price of solar modules has dropped dramatically in the last few years. As of September 1, 2011, installed systems are ranging anywhere from $4-$7 per watt before any available incentives or tax credits.Get bids from at least three installers.
You will not be taxed on your solar energy system if the energy produced is used for your property.. The form to declare a renewable energy property tax exemption must be filled out yearly. http://www.window.state.tx.us/taxinfo/taxforms/02-form06.html
May I increase the size of my system at a later date?
Absolutely, provided you have the unshaded space
*Thanks to Austin Energy for allowing us to use their FAQs as a basis for information and to Leslie Libby for her help in creating a general use guide for those interested in solar pv.