Solar panels are manufactured using similar methods as the manufacture of computer chips and glass panels.

How much greenhouse gas does solar panel manufacture emit? The answer depends on the type of solar panel, says Vasilis Fthenakis, head of the Photovoltaic Environmental Research Center at Brookhaven National Lab. Fthenakis and has conducted extensive research on the environmental impacts of solar and compared it with other technologies like fossil fuel to get a better idea of the big picture. “There’s nothing that’s completely risk-free,” says Fthenakis. “But photovoltaic compares very favorably with all other technologies.”

With today’s technology, the energy required to manufacture a solar panel is roughly equal to the energy that panel will produce in less than 2 years of operation. Given a 30-year panel life, a solar panel produces clean energy for over 28 years after its “energy debt” has been repaid.

Solar panels last 30 years or more. The industry standard panel warranty is this:

• 10 year workmanship warranty
• 25 year power warranty

Some modules, such as Trina, have a linear power warranty. Most however, have a two-tier step warranty that guarantees this:

• 90% power at year 10
• 80% power at year 25

Solar panels degrade gradually over time with exposure to sunlight, wind and weather. Panels are typically warranted 25 – 30 years and have a design lifespan of over 30 years. Energy production is expected to degrade by about one-half of one percent per year.

Inverters are warranted for 10 – 15 years and have an expected lifespan of 15 – 20 years. Future inverters will likely have longer lives. You may need to replace an inverter once in the system’s lifetime and we figure that cost into our financial predictions.

All other system components have service lives over 30 years.

Grid-tied solar electric systems automatically feed power into your house. Any excess electricity produced by the solar system and not used by your home is put onto the electric grid and spins your electric meter backward. Your utility credits you on your bill at the retail rate for the kWh produced.

Solar panels operate in this manner: When sunlight is on them, solar panels produce DC electric current. The DC electric current is passed through an inverter and converted to AC current synchronized with the local utility lines. The utility company provides power as normal. The solar panel system serves as an additional power source, fully integrated with the home or building’s existing power sources and the utility grid.

Most of the potential issues facing modules are covered by manufacturer’s warranties. Apart from those issues, we have replaced panels for the following reasons, not covered by warranties:

• Tree branch fell on array
• UPS truck backed into array
• Bullets fell from sky and pierced panels

This is what insurance is for.

However, the bulk of potential solar panel damage can be mitigated by choosing an experienced solar installer and using top-quality equipment.

We know of other installers who have replaced modules for these reasons:

• Baseball cracked modules mounted in the outfield of a ballpark
• System caught fire due to combination of poor design and poor installation
• Wind blew apart a poorly designed or poorly installed solar array

Solar modules are certified to withstand hail – not Texas-sized hail balls, but your typical hailstones. One quality solar panel manufacturer put it this way: “The panels are tested by shooting balls of ice at terminal velocity at the module in 11 specific spots. The ice balls can be of different sizes and the firing velocities change based on size. Typically solar panels are tested using 25mm balls fired at 23 m/sec. However, the spec also defines larger and smaller ball sizes from 12.5mm fired at 16 m/sec to 75mm fired at 39.5 m/sec. I have yet to see a panel with tempered glass fail using any size ball/velocity. I have seen a few cases of the roof being damaged beyond repair by hail and the unbroken solar panels need to be removed so the roof can be replaced. 

In short, we test our solar panels extensively for hail survivability. They pass quite well. However – all panels must pass this testing or they could not be certified to put on the roofs of houses, so this may not be a unique selling point.”

In other words, it is a common question, but usually a non-issue. Hail that will break car windshields is hail that will break solar panels. How often do we see such hail? Hardly ever.

“A competitor says his system has an AC-DC derate of 95%. Why is yours so low?”

On his blog, Dave Beumi notes: “Derates are the various locations and instances in a PV system where power is lost from DC system nameplate to AC power. This includes inverter loss, resistive factors, environmental conditions and issues relating to maintenance… The PV industry and its financing partners rely on simulation modeling software, which provides a fairly accurate multiple year forecast of energy production and economics, including [solar] financial payback. These models are thorough, sophisticated software packages which take into account the many variables which affect a PV system’s performance including weather, environmental conditions, technology and product performance, government subsidies, and cost of money among others… While the model takes into account the derate factors and a detailed weather history for a given location, its important to note that annual fluctuations in weather conditions is an important variable which can be significantly different year to year. Overall, simulation models are quite accurate and are a fairly good gauge for finance companies to make an informed investment decision.”

PVWatts makes it calculations using whatever derate number the user inputs. Our experience has born out that 81% is a reasonable but conservative derate. There are technical reasons why we could use a higher or lower factor, but that would take several pages of explanation and probably put you to sleep.

Suffice it to say, that 95% total derate is a physical impossibility. Any solar installer telling you that is not being truthful.

“Another company gave me a much greater energy production estimate than yours.”

We hear this occasionally. When asking the question, “How much electricity will a solar energy system produce” people sometimes get different answers from different companies.

Our production estimates are conservative — we try not to over-state the amount of energy you can expect to get from a specific-sized solar energy system. An internal company mantra of ours is, “Under-promise and over-deliver.”

That said, we use standard industry tools to make our energy production estimates. For most of our energy production estimates we use PVWatts, which is a publicly-available tool for solar energy estimating put out by the National Renewable Energy Labs (NREL) for anyone to use.

Like any calculator, NREL’s takes a bit of skill and knowledge to use. We have, on occasion, walked a prospective customer through the process to help them understand proper data input as well as how to interpret the results.

There are other solar companies that offer sky-high estimates and unrealistic promises. We do not.

 

We have sourced, tested, and used low-cost Asian solar panels — from reputable manufacturers. We don’t just investigate the panels themselves, we background-check the company that makes them. Solar panels carry 25-year warranties, and we want to make sure their manufacturers are financially sound and reputable, and will be around to support those warranties. This kind of careful research is an important part of the value we deliver to our customers.

We have a computerized pricing system that generates the total price for your solar project, based on the size of the system and your project specifics.

In general, the cost breakdown for a solar electric system is about 55-60% for the equipment itself (including panels, inverter, wire, conduit, switchgear, etc.); about 10-15% for overall project management, design, paperwork, permits and fees; and about 25-35% for the installation costs.

We can deliver excellent pricing on our projects thanks to two advantages: First, we pool our buying power with a national group of solar installers in a member-owned purchasing co-op to get advantageous pricing on the very best equipment (we will not compromise on quality where our reputation is at stake). Second, we are crazy about efficiency, and have been working for 14 years on how to deliver the very best-performing and longest-lasting solar installations with the least waste possible, thereby turning our customers into raving fans. It is a formula that works.

Solar is a new, emerging industry. To date, there are no industry standards for how to predict the energy output of a completed solar system in the real world. Each solar sales person can use his own assumptions in making this prediction. Some are intentionally optimistic, some are naïve and don’t have enough experience to make realistic predictions. As a company, our approach is to be intentionally conservative in making performance predictions. We live by our reputation and we want you to be very satisfied with your solar system. We’d rather lose the sale than make an overly-optimistic prediction and have you end up disappointed in a couple of years. Our company mantra is, under-promise and over-deliver. We feel it’s the best way to be as a company. And it is one of the reasons why we are a B Corp.

We build great solar electric systems. We under-promise and over-deliver. And we sleep very well at night.

The percentage of annual utility offset you can achieve with solar is driven by several factors, starting with how much energy your house uses. The size of the solar panel system, the type of panels used, and the orientation and shading of solar panels determine the clean energy output that is possible.

In some case, when a customer wanted to produce more power than their rooftop size would allow, we have built a combination system using rooftop and ground-mounted solar panels. We have also used solar panels to build awnings and other shade structures.

Alternatively, we recommend using SunPower modules to maximize your clean energy output. SunPower panels are unparalleled in terms of energy production. They have the highest output per square foot and deliver more energy per kW, year over year, than other modules. However, that extra efficiency costs more to achieve. So, if your primary consideration is maximum performance, then you should go with SunPower. If your primary constraint is cost, then we recommend one of our other brands of modules.

One of the reasons many people prefer Smart Solar Financing over leasing is that it is simply a better deal. With a lease, several companies and their investors all need to earn a profit. When YOU own the system, there is only ONE investor – you. With solar ownership, all of the financial return goes to you, so that even if a solar project in OH doesn’t have enough of a return to please the tax equity investors, venture capitalists and others that seek to make money through solar leases, it DOES make financial sense when YOU are the investor. As the owner of the system, you can take the Federal Tax Credit, sell your SRECs, and benefit from stable energy prices over time, as utility rates rise.

All solar panels lose a small amount of performance every year. Exposure to direct sunlight puts physical wear-and-tear on any material — think of lawn furniture, decking or shingles. The performance degradation of solar panels is expected and is very slight, only one-half of one percent per year. The panels are warranted to produce at least 80% of their rated power at year 25. In fact, they will continue producing power long after that, just a little bit less each year.

For efficiency sake, we have a large supply of Trina solar panels. Trina is a world-class supplier of high-quality panels. Using them enables to us to use the highest quality equipment at the best prices and maintain a very efficient delivery operation.

However, we are not wed to any one manufacturer. There are approximately 80 solar panel manufacturers offering about 600 different makes and models of equipment. One of the values we bring to our customers is that we can select the very best equipment for your particular job.

When choosing solar panels, we have three filters:

1. technology platform
2. specific performance and industry reputation
3. financial stability of the manufacturer

We are very careful in selecting quality solar panels from top-tier companies that will have the longevity to honor the warranties for their equipment. We offer many different solutions that are comparable in efficiency. We can also offer ARRA compliant solar panels (American Content) if that is a requirement.

We are also an Authorized Dealer of SunPower systems, which are the most efficient and energy dense solar panel available. There is a premium price differentiation for SunPower, but you can achieve more electrical output per square foot if you install a SunPower system, which would increase your system size and overall annual utility offset. SunPower is also a terrific solution when the roof is small but you want to maximize the amount of clean energy produced.

We have experience with installing both micro-inverter systems as well as centralized inverters systems and can help to accommodate what is best for your renewable energy and project goals. One obvious diffidence between micro-inverters in comparison to centralized inverters is an increase in price to install micro-inverters.

Some pros for micro-inverters:

1. ad hoc expandability
2. optimal performance under shaded conditions

Micro-inverters can, in theory, allow for easier incremental expansion of a solar array. But there are still the costs associated with mobilizing the crew and the question of racking. Do we build the whole rack now, or built the racking out in phases as well? Depending on the roof, this could be a limiting factor. Also, you can’t just keep adding micro-inverters forever. Even micro-inverters have limitations on how many can be connected together. If we install close to that limit today, then you’ll still be limited in future.

Some cons for micro-inverters:

1. They are installed on the roof under the solar panels where high heat could reduce their life, whereas central inverters are installed elsewhere, and have a documented history of reliable performance
2. Using micro-inverters increases the number of inverters for potential service repairs
3. Currently, micro-inverters cost more.

Micro inverters can also create more potential future maintenance risk. With a central inverter, you have a single point of failure; with micro-inverters, you have many points of failure.

In our opinion, micro-inverters are not worth using if you have a large, simple roof, without much shading. However, micro-inverters can be worth the added cost if you have a complex roof, where the modules will have multiple orientations, or complex shading patterns.

Most important to remember is that micro-inverters are still new technology and have not been proven enough yet to wear their “25 year warranty” with any kind of credibility.

Why on the roof? Why not on the ground?

We can build solar panel systems on the roof or on the ground. Rooftop solar offers a lower-cost option. The roof is an existing structure that can usually serve well as a mounting surface for solar panels.

A ground-mounted solar system requires a foundation and may demand a long underground wire run back to the house.We have built many ground-mounted systems, usually at a slightly higher cost than a roof mount.

Either type of installation can work well. We can provide whichever option you prefer, and we will advise you as to our opinion of which will work best in your case.

Solar panel subsidies and incentives might increase in the future—if I install solar panels now, will I miss out on solar panel incentives?

There are two broad classes of solar incentives: Purchase-based incentives and Performance-based incentives.

Purchase-based incentives are tied to the cost of the system, and apply one-time-only to the purchase of a new system using brand new equipment. They are designed to reduce or offset the initial cost of purchase. These incentives include tax credits (like the current Federal Tax Credit of 30% on renewable energy systems), low-interest loans, grants, and rebates.

Performance-based incentives are tied to the ongoing energy production of a solar system. There are several types of performance-based incentives, including Feed-in-tariffs, performance payments, Solar Renewable Energy Certificate sales, and a range of Carbon-tax or Carbon Cap & Trade mechanisms. What all performance-based incentives share is a solar income/savings structure based on the quarterly or annual output of the solar energy system—not a one-time-only payment, but an ongoing revenue stream as clean electricity is produced.

In a purchase-based incentive, the system owner must purchase the system within the time constraints of that particular incentive program. Performance-based incentives can apply equally to new and existing systems.

For several years now, the solar industry has been trending away from purchase-based incentives and toward performance-based incentives. This trend is expected to continue at both the state and federal level.

The advantage of this trend is that it makes project timing less critical—there is no need to wait for some potential future incentive. If and when that future incentive arrives, it will most likely take the form of a performance-based incentive and therefore be available to owners of existing solar energy systems.

Like all emerging technology-based businesses, the solar industry continues working on technical improvements. According to physicists, the theoretical maximum possible efficiency of a solar cell is 31%. Current laboratory cell efficiencies are hovering around 24%. So there is some room for growth in efficiency, but as the maximum efficiency is approached, each incremental increase is smaller and harder to achieve than the previous one.

Today, low-cost crystalline solar cells are by far the most dominant technology type available, holding 85% of total market share. Numerous laboratories continue to experiment with alternative technologies that could exceed the 31% efficiency cap of standard crystalline silicon, but none of these are close to commercial readiness. Any new start-up technology promising a significant efficiency boost would face serious cost hurdles and a long timeline to compete with crystalline silicon on a lifetime cost-of-energy basis.

While manufacturers have continued to improve solar panel efficiency, they have found more efficiency (and more savings) in reducing their manufacturing costs. As solar panel prices drop, it is that manufacturing efficiency, and the growth in scale of solar manufacturing operations, that are driving those cost reductions. Solar panel prices are not likely to drop much further, because if they did, the manufacturers would be forced out of business.

Solar panel prices have been falling ever since the technology was invented. 40 years ago the solar cells alone (not counting the other components) cost $2,000 per watt. Today, an entire system, including permitting and engineering, can be built for about $2 per watt. The previous two years alone saw a nearly 50% reduction in solar panel prices.

However, as solar panel prices fall, the dollar amount of each percentage point becomes smaller and smaller. Today’s panel prices are so low that many solar panel makers are struggling to remain profitable. The solar panel manufacturing sector has entered a tough period of mergers, acquisitions, down-sizing and right-sizing. Currently, we are in a period of overcapacity on solar panels. How this will affect prices in the future is not clear, but solar panel prices have stabilized in recent months and could soon begin to increase.

Historically, the solar panels were the largest piece of the cost equation in a solar energy system. As a result, the total system price trends followed the panel price trends.

Today, the substantial drops in solar panel prices means that the solar panels now have a much smaller affect on the overall cost of a complete system. Costs of the other equipment (which includes racking, inverters, wires, and conduit) are tied to the cost of commodity metals like copper, and these prices are not expected to decline anytime soon. Labor prices, project management costs, and engineering costs are currently at their most competitive and will likely not decline further.

Meanwhile, increases in other project requirements (such as structural engineering and permit fees, and electrical safety and project oversight requirements) are gradually adding to the list of cost items incurred on any project.

On the whole then, the price of a solar system is expected to remain fairly constant for the foreseeable future. Any reductions are projected to be small, while the possibility of price increases becomes more real as the market shakes out.