The Solar Energy Blog

Solar Power FAQs

There are so many questions that customers have when making the decision to invest in a solar PV system. We’ve put together a list of some frequently asked questions that we get from our customers that we have found really helpful to our customers and prospects.

How long does the photovoltaic (PV) module last?

PV modules last a long, long time. In decades-long tests, the fully developed technology of single and polycrystalline modules has shown to degrade at fairly steady rates of 0.25%-0.5% per year. Our solar panels/modules come with a 25-year power output warranty (reflecting the manufacturers’ faith in the durability of these products) and are expected to last at least twice that long. The power output warranty on the solar panels/modules is provided by the manufacturer of the panels/modules and states that at the end of the 25th year, the solar panels will still produce a minimum of 80% of their original power output. However, keep in mind that PV modules are seeing only six to eight hours of active use per day, so we may find that life spans of 40-50 years are normal.

What about reliability and maintenance on the system?

Reliability: Solar electric systems are a proven technology and are extremely reliable. PV cells were originally developed for use in space, where repair is extremely expensive, if not impossible. Most manufacturers guarantee that their solar modules will produce 80% of their initial production rating after 25 years.

Maintenance: Once installed, the solar electric system requires little or no maintenance (especially when storage batteries are not used) and will provide electricity cleanly and quietly for 25-plus years.

How strong are the panels/modules?

The panels/modules are Underwriters Laboratories Inc. (UL) certified and tested to withstand hail, hurricane force winds and rainstorms.

What is the maintenance on the PV panels/modules?

Because PV modules have no moving parts, they are virtually maintenance free.

How will the weather affect the solar electric system?

Solar electric systems are designed to withstand all weather conditions. Lightning, wind up to 120 miles per hour, and extreme temperatures are all things the solar system can handle. However, these conditions may temporarily reduce energy production.

How does a solar electric system store electricity after the sun goes down?

The most basic solar energy system is what is known as a “Grid-Tie Only” system. There are no storage batteries. Excess electricity produced by the solar panels/modules will be directed back to the local utility grid. You will receive credit for any power that you “sell” to the utility company. This is what is known as Net Metering.

What is Net Metering?

Policies for net metering vary from state to state. Solar net metering allows electric customers who generate their own electricity using solar energy to bank excess electricity on the grid, usually in the form of kilowatt-hour (kWh) credits. These credits are used to offset electricity consumed by the customer at a different time during the same billing period (i.e., when a facility’s solar energy system is not generating enough electricity to meet the facility’s needs). In effect, the customer uses excess generation credits to offset electricity that would otherwise have to be purchased at the utility’s full retail rate. Net metering is accomplished by installing a bi-directional meter.

Does the solar system produce electricity on a cloudy day?

Yes, a solar panel does produce electricity even when it is not placed in bright sunlight. On a normal cloudy day, there is always enough solar irradiance, by which the panel will produce electricity.

What happens when I need to re-roof?

The solar project developer is aligned with roofing experts, and will not install solar without complete assurance that it is in the best interest of the property. Developer will protect the warranty when installing on newer roofs. NOTE: A roof inspection is conducted to ensure the roof is in good condition prior to installation.

A Guide to Residential PV, Part One

As a homeowner who is interested in solar, you will most definitely start out with a lot of questions. A quick session of Google research might lead you into a sea of information, which can be overwhelming and daunting. We can begin to navigate some of this information by the simple process of understanding how solar photovoltaics work, and thereby pre-qualifying your home for a system.

Simply put, solar photovoltaic (PV) systems use solar panels to convert light from the sun into electricity. Each solar panel has the potential to capture and produce a certain amount of energy in the form of power, or watts. More solar panels equals more power production. Behind this simple concept is around fifty years of intense and ongoing scientific research. Ultimately what it boils down to in terms of residential PV is three questions:

  • 1. How much power do you want to create?
  • 2. How much space do you have to work with?
  • 3. How much light do you have?

You probably already know the answer to the first question, and it probably has a lot to do with your monthly electricity bill.  Determine how much of your bill you want solar to offset. In some cases this can be 100%, whereas for larger homes even 50% is a huge help. With your ideal power output in mind, move on to the next question.

More often than not, the question of available space comes down to roof size, with the exception being if you own enough property to warrant a ground mount system, or if you are set on a custom structure (think carport, single and dual axis trackers). Major factors to qualifying a roof go in this order: roof age, shade, and azimuth. If the roof is older than 10 years, most utility rebate programs will not consider you. But do not let this deter you too much, as solar can potentially save you enough money for a re-roof to financially make sense. Shade can be an issue as well, but with enough space a good PV system designer can work around shade and obstacles to maximize your roof’s potential. Azimuth just means the orientation of the roof face. A roof facing directly south (180°) is ideal, but arrays can face as far west as 250° and as far east as 110° (depending on the utility’s rebate requirements when applicable).

Finally, as you might guess, the location of your house on the planet makes a big difference. This statistic is fairly intuitive and is available all over the internet. Places like Texas, Arizona, New Mexico and Colorado get a lot of sun, which is great for solar. Places like Alaska, Washington, Germany (nice try Fox News) are generally cloudier and will not receive as much solar irradiation. This does not mean solar will not work in a cloudier place, rather that we should manage our expectations.

There is plenty more to discuss in order to get a full understanding of residential PV, but we will leave it here for now. Look for future blog posts where we will dive further into the specifics of PV costs and qualifications. In the mean time, feel free to send us your questions or contact your local utility company for information about rebates.

Solar in Central Texas

The US now has over 6,400 MW of installed solar electric capacity, enough to power more than 1 million average American households, and the average cost of a completed PV system dropped by 33 percent in the third quarter of 2012 compared to the third quarter of 2011. Considering the amount of sun we get here, you would assume that Texans are especially privy to the solar rush – and you would be correct.

With Austin Energy’s rebate program fueling their goal of generating 35% of power consumed from renewable resources by 2020, and CPS Energy’s similarly strong rebate program fueled by San Antonio’s outspoken defender of renewables, Julian Castro, the future of solar in central Texas is promising.

Residential demand is steadily growing from neighborhood to neighborhood and HOAs are catching on to the community benefits of solar PV. Meanwhile, financing plans are being developed to bring the costs down to near grid-parity. Commercial customers are seeing similar advances, making the relevance of solar unavoidable to businesses facing the reality of increasing utility costs, particularly during the intense heat of Texas summers.

The fact is: it’s not a matter of if you will reap the benefits of solar PV, but when. Call Freedom Solar for a free site assessment and join the solar revolution.