Frequently Asked Questions

Published December 29, 2010


In addition to FAQs below, we have the Top 10 Questions to Ask a Solar Contractor!  


Top Question No 1: Is the contractor a full‐time solar installer exclusively focused on solar PV? 
LightWave Solar holds an unlimited TN electrical contractors license with an additional
solar panel designation.  We are 100% focused on turn‐key solar PV design and
installation with over 30 full‐time employees.  


Top Question No. 2: What is included in the contract amount?  
LightWave Solar provides turn‐key design and installation.  This includes:
a. Site evaluation to verify system design requirements
b. Electrical drawings and site plans by in‐house engineers
c. Completion of interconnection application, TVA Green Power Providers
Agreement, and all other interconnection paperwork required by local utility
d. Permitting
e. Equipment procurement (panels, inverters, disconnects, meter, conduit, wire,
etc. – everything needed for fully functional system)
f. Installation and inspections
g. Grid‐interconnection/commissioning with TVA and local utility
h. One‐year workmanship warranty


Go here for more Top Questions to Ask a Solar Contractor!

· How does a solar electric system work?
Sunlight excites electrons in solar panels, and electricity flows to the inverter where it is converted from direct current (DC) to alternating current (AC). Most systems are connected to the grid through the local utility. Local utilities partner with TVA to pay solar system owners for their solar electricity. This program is called TVA Green Power Providers, and solar system owners will receive 2 cents above the retail rate (GSA-1). Currently, this is about 12-13 cents per kilowatt-hour. TVA has another program for systems over 50kW, Solar Solutions Initiative, which pays about 8 cents per kWh. Green Power Providers and Solar Solution Initiative incentives for 2015 will be available for a limited time.
· What size system do I need?
System size is usually determined by available roof space and budget. We will measure your roof to verify space and shading. Another consideration is electric bill amount. Systems can eliminate electric costs or offset a significant portion. We can analyze your bills to determine the appropriate system size.
· How much does solar cost?
The cost depends on the amount of suitable space for the panels, the system size, and the amount of money you want to invest in solar. A typical residential system is 7 kW and costs about $23,000. This includes everything required to provide a fully installed, roof-mounted grid-tied system. Add-on costs would be required for ground-mount systems, long distance ground work, concrete work, extended travel, AC modules or battery back up (battery systems start at $17,500).
· What are the available incentives?
o An uncapped 30% federal tax credit is available in which 30% of the total cost of a solar installation is credited against your federal taxes. Businesses are eligible for MACRS Accelerated Depreciation as well.
o TVA’s Green Power Providers Program will pay the base rate (about 11 cents this year) plus 2 cents per kWh for all solar electricity production. For example, a 7kW system generates about 750 kWh per month on average, so 7kW would generate about $98/month on average. This would appear as a credit on your monthly bill.
o TVA pays $1,000 to residential customers who install grid-tied solar electric systems.
· What are the financing options?
       Our financing partners are listed on our website with links to their programs. Click here to view options and get started.
· What steps should I take to decide if solar is right for me?
o Gather your last 12 electric bills to determine your annual use (or we can request your bills from your electric company).
o Think about how much how much money you want to invest in solar.
o Think about what site might be the best location. Solar performs best on south-facing roofs.  East/west roofs with low pitch are also suitable. There should be little or no shading from trees, chimneys, and dormers. If the roof is not suitable, we can install panels on another structure or on poles.
o We provide a free preliminary estimate and drawing.
· What happens during power outages?
A grid-tied solar system must shut down until utility power returns so that it doesn’t back-feed the grid. When grid power goes out, the inverter will automatically shut off. When the grid power is re-established, the inverter will automatically turn back on after it has synchronized with the utility grid.
· Will my system work on cloudy days?
Usually, yes, but it will be less productive. Production is proportionate to the thickness of cloud cover.
· How will I know if my system is producing what it should?
   The inverter’s faceplate shows production data. You can compare your actual production to our estimates to ensure your system is on track. Production monitoring that can be accessed on-line is available at an additional cost.
· How long does it take to install the system?
For a typical residential system, it takes about three days to install the PV panels and equipment.  Then, the system must pass a final State electrical inspection which normally takes one business day to schedule and pass. It can take another 7-10 business days for the utility to install the separate solar meter.  The local utility and LightWave Solar will turn on the system once the utility company has installed the solar meter.
· What are the panel and inverter warranties?
    The solar panels we install have a product warranty for 10 years and a limited power performance warranty for 25 years. The limited power performance warranty means that by the end of year 25, the panels’ actual power output will be no less than 80% of the labeled power output. Most ot the inverters we install are warrantied for 10 years. Some brands offer an extended warranty.
· What if I need a new roof or I am building a new house?
    You want your roof to be in the best condition possible because the average working life span of a solar system is around 30 to 40 years.  Thus, we don’t recommend installation on composition shingle roofs over 10-years-old. If you are building a new house, click here for guidance on building a solar-ready home.
· Can the solar panels withstand high winds and hail?
    The panels are supported by high quality stainless steel and aluminum racking systems designed and mounted based on American Society of Civil Engineer (ASCE) wind load provisions. All solar panels are tested to UL-1703 standards and are capable of withstanding one inch (2.5cm) hailstones at 50MPH.  They are covered with tempered glass, akin to a car windshield.  Additionally, the panels can be covered by homeowners insurance.
· Do I need approval from my homeowners association?
    Some homeowners associations have rules regarding the installation of anything on your roof or grounds. If you belong to a homeowners association, contact them and ask about neighborhood guidelines.  In our experience, most homeowners associations decide in favor of solar system installations.
· Will adding solar increase the value of my home?
    Yes! A solar system reduces electric bills, and it is a valuable asset to any homeowner. Click here for a 2015 Berkley Lab & Sandia National Lab report summary showing an average selling price increase of approx. $4/watt ($15,000 for 4kW system).
· What do I need to know about solar system installation?
    We mount solar panels on your roof and run wires through conduit to a solar meter.  From there, we also run wires through conduit to your breaker panel.  In the same vicinity as your utility meter, we mount an inverter, AC disconnect, and the solar meter.  This equipment can be mounted either inside or outside and takes up about 15 square feet (3′ x 5′ area).

Which is for you?  On grid, battery backup, or off grid.

We are frequently asked what happens when the grid is down and about batteries, etc. Click here to review three types of solar systems; grid tied, battery backup and off grid.