A solar pv array that is “grid-tied” is connected to the electric power distribution grid through your local electric utility’s power lines. These are the same lines that bring power into your home or business. Having a grid-tied array allows you to take advantage of programs that may allow you to sell power back to your utility company.
It is not necessary to have a battery backup for your solar array. If however, you are interested in having backup power in case of a power outage, or if you want to live “off-grid”, independently of the local electric utility, then you may want to consider this option. A solar array with battery backup is more complicated to install and can add as much as 25% to the cost of your solar array. Battery backed systems are also less efficient due to battery charging and additional system losses not present in basic grid-tied systems.
The more accurate question to ask is, “How many kilowatt hours (kWh) of electricity do you consume in an average month?” Obviously a home that is designed and built to be energy efficient will consume far less electricity each month than a similar sized home that is not energy efficient. Likewise, the choice of fuel, whether electricity or gas/propane, used for space heating, water heating, and cooking will affect the amount of electricity used monthly.
Do this…contact your local electric utility provider and ask them for a printout of your past 12 months kWh usage. Figure out the average kWh you consume each month and decide what your goals are. Do you want to offset your entire utility bill with solar power, or just a portion? Do you want to live completely free of the utility grid? Are you interested in having some protection against rising utility rates? Give us a call and we can help design a system that meets your needs and goals.
The physical size of a solar array depends on the output desired. Solar panels commonly sold today measure approximately 65” x 39”, weigh about 45 lbs, and are rated at between 200 and 230 watts each. A solar array rated at 1 kW would require 5 panels and cover approximately 90 square feet of roof area. Under ideal conditions (i.e. proper orientation, no shading) in Mississippi this 1 kW array would produce, on average, about 4 kWh of electricity daily (a 100 watt light-bulb will consume 4 kWh of electricity in 40 hours). That’s about 120 kWh a month on average. Using these numbers as a guide, a 5 kW array would, on average, produce about 600 kWh of electricity a month and would take up about 450 square feet.
No, pole mounts area readily available for mounting solar arrays.
Solar arrays are most efficient when oriented due south with an elevation that matches the latitude of the site. Slight variation, either east or west of due south may be necessary or even preferred under some circumstances. Elevation angles can vary significantly with only a minimal effect on efficiency.
A 100 watt (W) light-bulb consumes 1 kilowatt hour (kWh) of electricity if left on for 10 hours (i.e. 100 W x 10 hrs = 1,000 Wh or 1 kWh).
Solar arrays are often referred to as some multiple of kilowatts…a 2.4 kW array is a 2,400 watt array, a 3.2 kW array is a 3,200 watt array, etc. Commonly sold solar panels today are rated at between 200 and 230 watts (W) each. A solar array rated at 1 kW would require five 200 watt panels. Under ideal conditions in Mississippi (i.e. proper orientation, no shading) this 1 kW array would produce, on average, about 4 kWh of electricity daily or about 120 kWh a month on average. A 5 kW array would produce, on average, about 600 kWh of electricity in a month.
Today’s micro-inverter technology makes it easy to start with a small system and add to it later. It is important to have an overall plan to make sure the proper infrastructure is in place to support future expansion.
Most of the systems MS Solar installs are simple grid-tied systems designed to take advantage of current utility incentive programs. These systems will not run appliances or lighting in the event of a power failure. If this is a priority for you, MS Solar can design a system to fit your needs.
The installed cost for a basic micro-inverter, grid-tied system is between $8.00 and $9.00 per watt. Please contact us for a complete quote.
Yes, through 2016 a solar array installed at your residence or business qualifies you for a 30% Federal Tax Credit. Unfortunately, there are no State incentives in the state of Mississippi at this time.
If you are in the TVA (Tennessee Valley Authority) distribution area, your local electric utility participates in TVA’s “Generation Partners Program”, and your array meets their requirements, TVA will rebate you $0.12 per kWh above your current billed rate (about $0.10 per kWh) for every kWh your array produces and sends back to the grid. TVA also provides a $1,000 one-time rebate to help with installation costs. Please check with your local electric utility provider or with TVA to get full details.
Homeowner’s policies typically cover damage to your solar array for normal causes just as they would for any other item attached to your home. Please check with your homeowner’s insurance carrier about your plans to install a solar array and be sure you are covered.
Grid-tied micro-inverter based systems are virtually maintenance free.
Manufacturers typically warranty their panels to produce at least 80% of their rated capacity for 25 years. There are many cases of panels installed for 30 or more years that are still producing at high efficiencies.
How much you save will depend on what incentives are available through your local utility. For example: if your local utility participates in TVA’s Generation Partners Program you will be paid approximately $0.22 for every kWh of electricity your array produces (under the current rate structure). Borrowing from some of the earlier examples, a 1 kW array would, on average, produce about 120 kWh of electricity a month worth about $26. Using this as a baseline for calculation, you would need about a 4 kW array to offset your utility bill by $100.
Shading can significantly reduce the efficiency of your solar array. Ideally your site should allow full sun exposure to the array from at least 10am until 3pm, longer if possible. Though MS Solar never advocates the cutting of trees, sometimes minor pruning or thinning may be necessary. Some sites simply aren’t appropriate for solar.
When you contact MS Solar we’ll visit your home and conduct a thorough Solar Site Survey using special equipment that allows us to project the amount of electricity a given array will produce on your site. We’ll discuss the actual location of the array, orientation, and any shading issues we find while there. When we’re done, you can be sure that your array will perform as projected in the Site Survey
The micro-inverters used in most of our systems allow for online monitoring of the system for customers with internet access. We pay the fee for this service for the first two years and monitor all our systems on a daily basis to make sure they are functioning properly. If anything should go wrong with the array, we will very likely know before the customer does. You can see examples of this online monitoring tool at our website www.schoolsonsolar.com. For customers without internet access, simple monitoring equipment is available.
Revised March 10, 2010