Solar Southwest Florida

My wife will tell you that I was screaming at the TV last night while watching an episode of CSI. I’m one of those guys that points out every little factual mistake in TV dramas. The crack team of CSI agents were trying to determine which home in a neighborhood was using inordinate amounts of energy to identify a drug grow house. They had obtained the “energy” usage of a neighborhood of homes, and identified a home that consumed 5,300 “kilowatts” in one month – a sizable amount of energy supposedly. The problem is, a kilowatt is a measure of power, not energy.

It’s been a couple of years since I discussed the difference and relationship between power and energy, two words that many people use interchangeably, including CSI script writers apparently. Solar power and solar energy are often misused phrases as well, and it’s important to understand the two concepts to evaluate solar energy system performance (note that I called it a solar energy system).

To recap my previous post, energy is power over time. Power measures the instantaneous output (or input). Power is the ability to do something (to do work in terms of Physics). Energy is the amount of power consumed, or work performed, over time. We “consume” or “produce” energy in our homes and businesses, not power.¹

In theory, the CSI team could identify a potential grow house if they were able to see how much power was being consumed. In fact, it might even be easier to use power as an identifier, but they were clearly using energy figures to make their analysis.

Yesterday my 10kW rated solar energy system produced energy in the amount of 31.1 kilowatt-hours, but barely got above 8kW of power production at any time.

How does this relate to solar energy?

What can be confusing is that solar energy systems are often (usually) rated in terms of watts or kilowatts, which are measures of power. When you go to buy a solar electric system, you may be quoted a “5kW System.” That system rating is a measure of power – the ability to create energy. However, what you really care about is how it will affect your electric bill, or how much usable energy the system will supply to offset your utility bill. So why do solar energy contractors sell solar energy systems in terms of power, not energy?

The first answer is that it provides an apples-to-apples comparison point for you to make a purchasing decision. While all solar equipment is not created equally, at least there are standard test conditions on which we can compare component and system ratings. Using energy production as a comparison point can be dangerous because assumptions made by manufacturers and contractors may be biased or have different degrees of conservatism applied. Since there are various models and sources available for energy production data, identical systems could be quoted as producing dramatically different energy values.

The second answer is that solar energy is variable. We have good models that estimate solar energy production, but we can’t predict the weather precisely. We can’t tell you exactly how much energy your system will produce in a day, week, year, or even a lifetime, but we can come close. Predicting precise solar power at any given instant is even more impractical. Nonetheless, we have standardized ways of determining maximum power output that can be duplicated and tested, but we have no definitive, accepted, or regulated way by which we can provide an energy rating. Furthermore, we would have to wait 25+ years to prove out energy production on a given system.

The final answer is that it’s far too dangerous to “promise” an energy production figure unless the promise is grossly underestimated, which puts dealers at a competitive disadvantage. In some states, power production agreements (PPAs) are popular because the system installer is paid for energy produced rather than charging you up front based on a power rating. PPAs typically skew benefits to the seller, but do provide a way for people to get into solar with low or no up front cost. Note: PPAs are not legally available in Florida due to arcane and outdated laws protected by well funded utility lobbyists. Nonetheless, PPAs often provide the power ratings of systems for comparison purposes.

Would you buy one car over another just because it’s the same price, but has double the horsepower? Of course not – fuel efficiency, size, and many other factors come into play. more importantly, how often do you utilize “peak horsepower” anyway? That brings me to my next point…

The rated power of a solar energy system will almost never be seen. Since the power rating of the system is based on standard test conditions of the solar modules, a lot of things have to come together for peak power to be observed. The sun’s angle, irradiance, temperature, haze, cloud cover, time of year, time of day, module soiling, age degradation, shading and other factors all impact solar module performance. In addition, solar modules are often, if not usually, rated well above the inverter output rating. For example, it’s common practice to pair a 250W solar module with a 215W microinverter.² As a result, the theoretical power limit of the system can by substantially lower than the rated power that is given for comparison purposes when proposed to a potential buyer. That’s okay – remember that we are ultimately concerned with energy production, not power output. “Oversizing” the solar modules relative to the inverter typically results in overall greater energy production and cost effectiveness.

Misunderstanding about how power and energy differ is prevalent, and it’s frustrating to solar energy professionals, as proven by my recent outburst at an inanimate object. In many countries you can prepay for energy in “units,” and I have found that people there are much more cognizant of energy use. Knowing how much power your devices and appliances require is only half the battle. Understanding energy, power over time, is critical. The same applies to solar energy systems – the focus should be on energy production, not power output alone. Nonetheless, we are stuck with power ratings to provide meaningful comparisons.
¹ Energy cannot really be produced or consumed (created or destroyed) – it’s just transformed – see the Physics Law of Conservation of Energy.
² For a discussion of why, see Enphase’s “module rightsizing” paper here.

Artistic rendering of my Fort Myers solar electric system prior to installation.

It has been extremely exhausting, but I finally completed installing a 10kW photovoltaic (solar electric) system at my home in Fort Myers, FL today. The final interconnection was done by my electrician and we fired up the system. To my delight, even with dense cloud cover, my meter started spinning backward!

I see this happen many times each year, but now I know the feeling of producing my own energy. I now understand why customers are so antsy and anxious about their installation schedules. It’s EXCITING to be your own power plant! I now understand why people want it, and more importantly, why they want it NOW!

While the job was contracted through my employer, Fafco Solar, I did much (most) of the work myself to learn what our guys are up against on a daily basis. It was a tremendous learning experience, and reconfirms the massive respect I have for the hard work I ask our installers to do every day. Although I am deeply involved in the installation process for all photovoltaic systems installed by Fafco Solar, it’s been quite a while since I “turned a wrench” myself.

The hardest part was definitely getting the panels to the roof, carrying them around, and holding modules up just enough to plug them in and ensure tidy cable management. My wonderful wife pitched in to help me hoist and place some of the panels. Despite this tough task, I found that other aspects of the installation were almost as hard as the heavy lifting. Maybe I’m just getting old, but the attachment points took a lot out of me with all of the bending and kneeling, and setting the rails was not as easy as I thought it would be. All in all, it was hard work, but very satisfying.

Because of the confidence I have in the brands, and the advantageous pricing through our supplier network, I installed:

• 40 Canadian Solar CS6P-250P Solar Modules rated at 250W each
• 40 Enphase M215 Microinverters
• IronRidge rails with some Unirac Hardware
• SolaDeck Roof Junction Box
• Square D Fusible Disconnect

Below is an awesome panoramic view of my solar electric system (if you can’t see it or interact with it, click here):

This system should knock my electric bill down to zero with some of the other energy saving upgrades I have made over the years including a variable speed pool pump and LED pool lights. I expect that I will just pay a small customer charge to FPL each month. You can see my system monitoring live – click here!

I do have some shading issues I want to address, which will require trimming some trees, especially at the southwest corner of my house. It’s long overdue anyway, and will help keep my gutters clear. This known issue is why I shifted the installation of my solar panels to the east on the south roof. It still looks balanced on the roof.

I can’t say enough about how good it feels to be “independent” from the utility company. I’m not exactly independent, because it’s a grid-interactive solar electric system, but I am independent from ever-increasing electric rates and fuel surcharges. I have created a hedge against surely higher future rates as well as potential future inflation. In a way I am now a competitor of the utility company. I can produce electricity cheaper than they are willing to sell it to me, so I choose not to buy it from them! The satisfaction is overwhelming.

I’m sure the afterglow of my newly installed solar electric system will fade, much like the feeling of getting a shiny new car (which I also bought recently). However, the monthly reminder from a low (or negative) electric bill will keep that new car smell going on my roof for the next 25+ years, if I choose to live here that long. With a zero electric bill, it will be a harder choice to leave!

Fafco Solar just completed a 38.25kW Solar Photovoltaic System for FMI Hansa Medical Products in Naples FL. The rooftop solar array is comprised of 153 solar modules from Canadian Solar rated at 250W each. The microinverter-based system uses 153 Enphase M215 microinverters mounted beneath each solar module.

FMI Hansa representatives contacted me less than a month ago after realizing that the original company contracted to install the solar panels was not meeting its obligations. The owner had a strict November 20 deadline for a ribbon cutting ceremony at their beautiful new facility at 3511 Plover Ave, Naples, FL. Based on what I observed, the contractor was hopelessly headed in the wrong direction. Half of the materials had been delivered, and they were unable to procure the remaining materials required due to a manufacturer bankruptcy. The design was flawed from the beginning and the materials on-site did not match the plans.

The original contractor was terminated and I recommended that we go back to the drawing board – a bold recommendation given the short time-frame allotted for the project. In three weeks after signing a contract we were able to design, engineer, permit, procure, install, and inspect the system just in time for the ribbon cutting.

This system used non-penetrating S-5 clamps to attach the solar rails to the standing seam metal roof, just like the Naples Botanical Garden solar energy system just down the road from this site.

If you are in need of a commercial solar electric contractor in Naples, FL, call Fafco solar and we will get the job done – on time, and on budget.

Microinverters and Electrical Conduit

51 Panel Solar Array (of 153 Total)

Microinverters on Solar Rails

FMI Hansa Solar Electric System 38.25kW

FMI Hansa Medical Products, Naples FL

I’ve been relatively quiet about the 10 kilowatt solar electric (photovoltaic) system that I am installing at my home in Fort Myers, FL. Normally I would be writing incessantly about something like this, but honestly I didn’t think it would go the way it did. I decided that I would learn what the hard working men of Fafco Solar endure every day on rooftops while installing solar energy systems. In particular, I wanted to experience the roadblocks that come with installing a solar photovoltaic system, the most complex product Fafco Solar offers.

Photovoltaic systems require the most planning, integration, skill, and physical labor of any solar installation. I am well aware of the planning process and integration with the home’s electric system. I have the skill required to do the work, having done quite a bit of hands-on solar in my earlier years. What I learned (or remembered, perhaps) is how physically demanding this work is! I had the luxury of installing my solar electric system at my own pace, but with a rebate check riding on the completion, I have been pushing pretty hard.

I have the attachments, rails, and inverters installed. Next up is the wiring, then finally the solar modules.

I received a question from a potential customer today about power production guarantees for Photovoltaic (PV) Systems. I realized that I hadn’t covered that issue on my blog, so I thought I would copy the question and response here (revised for clarity).

Question: Is there a guarantee on the percentage  power output of the proposed photovoltaic system?

PV System Output is Reliable and Predictable

Answer: The Canadian Solar CS6P-250P modules themselves have a power production warranty that states basically that they will put out a minimum of 97% of rated power at test conditions during the first year and degrade no more than 0.7% per year thereafter through a total of 25 years. This is the primary power production warranty that will be applicable to your question. It is what they call a linear power warranty, meaning the degradation per year is expected to be 0.7% or less. This differs from traditional module warranties in that they have a tiered power output warranty (i.e. 90% production for years 1-10 and 80% in years 11-25).

The Enphase M215 inverters also carry a 25 year warranty. There is no degradation rate specified for inverters. Generally they just work or don’t work at their rated efficiency level, which is very close to 100%, meaning they convert almost all of the energy from the panels into AC electricity. The benefit of a microinverter system is that you can easily detect deficient modules or inverters by comparing production levels to “neighboring” units through the monitoring system. There is “nowhere to hide” if a module or inverter fails.

There is no power production warranty at the system level. The individual components have their own warranties, but neither manufacturers nor dealers provide system level production warranties typically (unless set ridiculously low). The reasoning for this is that power production is variable with weather. We can predict long-term production levels quite well based on 30+ years of weather data available through the National Renewable Energy Labs and other sources, and they provide a variety of tools for energy output estimation. However, in any given day, month, or year the production level can vary quite a bit.

To give you a frame of reference, National Renewable Energy Lab’s PVWATTS estimator predicts the Naples Botanical Gardens PV site in Naples, FL will produce 51,673 kWh per year. The attached system monitoring reports shows that the actual production was 56,013 kWh over the last 365 calendar days. The prior year that number was 59,107 kWh. As you can see in the reports, there is significant daily variability in the production level based on weather.

We have seen all of our Enphase based systems outperform the PVWATTS estimates over the last three years. It’s hard to say whether that is a result of the microinverter technology, which claims a 10-15% advantage over string inverters, or if we have had exceptionally good weather.

What I can tell you is that PV systems provide a reliable energy production in the long run. Many in the industry use a +/-10% figure to describe typical annual variability. I have found that to be the case in our area for systems we monitor.

Attachments:

Enphase Energy – Enlighten _ FGCU Naples Botanical Garden
Enphase Energy – Enlighten _ FGCU Naples Botanical Garden (2)

—-END RESPONSE—-

My company has never offered a power production guarantee. The way to get a real guarantee is to enter into a Power Purchase Agreement (PPA), which is somewhat like an equipment lease whereby you just pay for the energy produced by the system. You essentially pay someone other than the utility for your energy at a locked in rate for a long period of time. This can be an attractive option for many. Unfortunately, PPAs are effectively banned in Florida because utility monopolies have a exclusive right to sell power in the state, and you may not sell energy unless you are licensed/chartered to do so. In other words, if you wanted to put a solar electric system on your home and sell excess power to your neighbor, you could not legally do so. Some leases also come with power guarantees that are not very ambitious, but again, leases are not popular in Florida for a variety of reasons.

The good news is that we do have netmetering, whereby you can sell excess energy back to the utility company at the retail rate (up to a point). While there is no power production guarantee for the typical customer owned renewable energy generation plant, the output is very reliable within a fairly tight range of solar photovoltaic production.

Yeah, so? Some disingenuous competitors love to tell a story about how FAFCO solar pool heating panels, which have a patented subheader for better flow distribution, burn up pumps due to high “back pressure.” They also claim that FAFCO panels cause you to use more energy because of this increased pressure. Really?!

This typical pool pump performance curve shows that a small increase in head pressure is inconsequential if the pump is sized properly for best efficiency to begin.

Here are the facts:

• A FAFCO Sunsaver solar pool heating panel does have five times the pressure loss (also known as head loss) than one major competitor’s panel at the recommended flow rate. That sounds bad. However, this is inconsequential when you consider the range of capability of a normal pool pump. The competing panel’s head loss is 0.4 feet of head versus FAFCO’s 2.0 feet of head.  If the pump is properly sized for the pool to begin with, this increased pressure will result in approximately 4% less flow, which again is inconsequential. It certainly is not enough to “burn up” a pump. Pump bearings can deteriorate quickly from excessive heat caused by very low flow rates, but you would have to cut the flow from a properly sized pump by more than half to begin to see detrimental effects.
• FAFCO systems use 2″ panel headers and PVC plumbing versus 1-1/2″ by some competitors. The head loss from the smaller pipe is more consequential than the panel resistance. In fact, 100 feet of  1-1/2″ plumbing adds about 3 feet of head more than 2″ plumbing. As a result, FAFCO systems typically have similar or lower resistance than competing systems.
• All roof mounted solar pool heating systems have head loss from the height of the panels. If the upper header is above the pump, you are adding resistance to the system. The added head loss from normal roof height is typically more than the panels and plumbing combined.
• As a rule of thumb, most solar pool heating systems will add about 5 PSI, or 11.5 feet of head to the pump.
• Finally, more resistance equals lower flow rates equals LESS energy use, not more. It might sound counter-intuitive that a pump with more resistance uses less energy, but it’s true. If the pump does less work because it is moving less water (moving water slower), it uses less energy.

If someone tries to convince you that adding solar pool heating panels to your pool will burn up your pump, it’s nonsense. Show them the door. Reputable installers and salespeople will evaluate your existing system and advise you if there are any factors that might cause a solar pool heating system to perform in a sub-optimal manner or damage existing equipment, but “back pressure” from FAFCO’s subheader is not one of them.

Sometimes we are asked by a home or business owner why they have to sign a Notice of Commencement (NOC) when installing a solar pool heating, solar water heating, or solar electric system. Buyers may not realize that when purchasing a solar energy system, they are entering into a binding construction contract, which falls under the Florida Construction Lien Laws. Any time permitted improvements are made to real property, owners should consider a contract to be handled as any other construction contract. The laws are a bit complex, but the purpose of a NOC is pretty simple:

• It notifies the jurisdiction that improvements are being made to real property.
• It is required by Florida Statute that the building department NOT inspect a job valued over $2,500 unless an NOC is filed, even if a permit has been issued.
• If a contractor is not paid for its work, it can attempt to lien a property in an attempt to collect (subject to complex and strict requirements).
• It can protect a homeowner from a contractor that does not pay its subcontractors or suppliers.
• It may limit the payment liability for homeowners to the value of the project.

The NOC must be notarized in most jurisdictions, but some just require a signed document. Your contractor will be able to provide the correct form and requirements. Once completed, the contractor will file the NOC with the Clerk of Courts and obtain a certified copy, which is supplied to the building department. Only at that time may a building official complete inspections of permits.

The NOC is common practice in the construction trade, and helps owners and contractors comply with Florida law and protect themselves against contract disputes. If you are concerned with the ramifications of this document, talk to your contractor or consult your attorney. There is nothing to fear from an NOC as long as you intend to pay for the value added to your property in accordance with a valid construction contract.

The requirement for a building department to have a NOC filed with the County Clerk is found in Florida Statute 713.135(1)(d). The complete text follows:

713.135 Notice of commencement and applicability of lien.—

(d) Furnish to the applicant two or more copies of a form of notice of commencement conforming with s.713.13. If the direct contract is greater than $2,500, the applicant shall file with the issuing authority prior to the first inspection either a certified copy of the recorded notice of commencement or a notarized statement that the notice of commencement has been filed for recording, along with a copy thereof. In the absence of the filing of a certified copy of the recorded notice of commencement, the issuing authority or a private provider performing inspection services may not perform or approve subsequent inspections until the applicant files by mail, facsimile, hand delivery, or any other means such certified copy with the issuing authority. The certified copy of the notice of commencement must contain the name and address of the owner, the name and address of the contractor, and the location or address of the property being improved. The issuing authority shall verify that the name and address of the owner, the name of the contractor, and the location or address of the property being improved which is contained in the certified copy of the notice of commencement is consistent with the information in the building permit application. The issuing authority shall provide the recording information on the certified copy of the recorded notice of commencement to any person upon request. This subsection does not require the recording of a notice of commencement prior to the issuance of a building permit. If a local government requires a separate permit or inspection for installation of temporary electrical service or other temporary utility service, land clearing, or other preliminary site work, such permits may be issued and such inspections may be conducted without providing the issuing authority with a certified copy of a recorded notice of commencement or a notarized statement regarding a recorded notice of commencement. This subsection does not apply to a direct contract to repair or replace an existing heating or air-conditioning system in an amount less than $7,500.

Professionally installed Solar Pool Heating panels are an investment, and most people want to know how long Solar Pool Heating panels last. That’s a great question!

Solar Pool Heating Panels last a long time!

Most major manufacturers provide a 10-12 year collector (panel) warranty that covers manufacturer defects. FAFCO even offers a 15 year warranty on its Revolution panel. That shows you how confident the manufacturers are in the quality and longevity of a typical solar pool heating panel. Considering that over 100 million gallons of water can pass through a typical solar pool heating system in its lifetime, it truly is amazing how well solar panels stand up to the rigors of pressure, chemicals, sunlight, wind, and all of the other elements that affect them.

A different questions is how long can solar pool heating panels last? Because the industry is fairly mature, at least a couple of manufacturers have been around for decades. That means there are millions of panels out on roofs, and we get to see quite a few really old solar panels. Even in hurricane ravaged Southwest Florida, we still see panels from the late 1970′s and 1980′s without any major problems. Just yesterday we came across a 1987 system in pristine condition. The technician was on the roof installing a new solar tubular skylight when he noticed the aging but operational system. He joked that he was just six years old when the system was installed!

What’s also great is that, because we’ve been around so long, I can just look up the system in the database, and I see that we installed it on June 29, 1987. All of the ten panels are from 1987, proving that none have been replaced. In fact, we have no record of making any repairs to the panels or system, either. These panels have literally doubled the manufacturer’s warranty length and show no signs of needing replacement.

Because there are so many factors that go into the longevity of a solar pool heating system, it is hard to say how long any particular system will last, but to assume a system will last somewhere between the manufacturer’s warranty and 25 years would surely convince most that they will get their money’s worth.

Men may be from Mars, and Women may be from Venus, but both share an interest in Solar Energy. What’s interesting is the products each gender tends to buy.

At risk of sounding stereotypical and seriously impacting my home life, I decided to write this post anyway. I have fairly hard data behind my opinion, so I figure I can get away with it. I have found that men are the primary buyers of Solar Electric (Photovoltaic) Systems in Southwest Florida. On the other hand, women and men equally or collectively tend to drive the decision to buy solar pool heating systems.

The last 10 Photovoltaic (PV) systems we installed were purchased by:

1. Mr. A
2. Mr. Z
3. Mr. R
4. Mr. T
5. Mrs. A
6. Mr. Y
7. Mr. N
8. Mr. T
9. Mr. A
10. Mr. T

Do you notice a trend? Nine of the last ten buying decisions for PV were driven by male home or business owners.

On the other hand, Solar Pool Heating decisions tend to be a family decision. People enjoy their pool together. Solar pool heaters are typically a quality of life decision more than a straight-up investment decision (although solar pool heating is clearly the most cost effective way to heat a pool in Florida). I like to think of a solar pool heat buying decision similar to the decision to install a pool in the first place. It’s something that adds value to your home, will be part of your home for many years to come, and creates a new opportunity for enjoyment at your home.

Me Caveman. Me like warm Solar Heated Pool. Men like solar heated pools, but the benefit is far more subjective, where solar electric systems provide quantifiable results.

Sure, there are cases where one spouse is the driving force behind a solar product and the other is either skeptical or dead-set against it. Mrs. R. recently came into the office to express a strong interest in Solar Pool Heating. We thought we would be out any day to install the system, but she called back to let us know that her husband had vetoed the decision. As it often happens in my home, the wife got her way, and she called back to say that she had convinced her husband to proceed! Other times we find that men want to heat their pools for the enjoyment of their family – it becomes a gift to the family. But more often than not, it is a joint decision between a husband and wife to purchase a solar pool heating system. In fact, our solar advisors recommend that couples sit down with them together to learn about solar energy to make sure both are on board. There is definitely an educational aspect to solar pool heating sales. Solar pool heating is only popular on a large scale in a handful of states, so new and part-time residents usually need additional education on how it works. The vast majority of solar pool heating systems we sell have a couple making the buying decision and showing mutual interest.

I would be speculating as to why this phenomenon exists, but thinking back to the last three years of solar electric customers, I do not remember personally having any significant interaction with female buyers of PV systems. Of course, I can name a few… Mrs. P comes to mind… but they are not nearly as engaged in the ongoing performance and benefits from the system. Off the top of my head I can easily write down a dozen names of male customers who actively review their system performance and revel over the energy savings that their systems deliver. I just don’t see that kind of engagement from female buyers. My best guess is just that guys like stats and specs. That’s why we like sports, cars, and stocks. There isn’t the same kind of quantifiable monitoring or investment return from a warm pool. A warm pool is a much more subjective benefit.

[I can feel my wife, mother-in-law, and sister-in-law glaring at me at this point.]

A Happy Couple Loves Their Solar Tubular Skylight

While I don’t have as much hard data on other solar products, I can offer some subjective observations. Solar water heating decisions seem to be joint decisions that are strictly based on economic reasons. Solar tubular skylights seem to be joint decisions that are strictly a quality of life choice. Brightening a dark kitchen makes everyone happy. Solar attic fans are economic decisions that seem to be instigated by men.

There has to be more to it than “guys like numbers and girls like luxury.” In fact, there is a marketing rule-of-thumb that says women handle 80% of spending and purchasing for the household. Why is it that most solar electric spending seems to be done by men? Perhaps there are great women behind all of those great men. Maybe women are controlling the purse strings (or puppet strings – haha) behind the scenes. A possible factor is that the husband’s name just happens to show up on the contract – it’s a control thing – we can be like that. Usually the husband’s name shows up first on the title to the property, so it stands to reason that the contract is written in his name, right?

Whatever the reason, there is clear evidence that men are driving the purchasing interest and decisions to invest in solar electric systems. I find that odd given that solar electric systems are both an economic and an environmental decision, two areas in which women generally take great interest. While the up-front costs of a solar electric system are higher than that of other solar products, there are other home renovations like kitchen and bath remodels that are equally or more expensive and that are likely to be shared decisions.

While my observations may sound stereotypical, I believe there is enough hard data to back them up. I would love to hear your perspective. Learning how people perceive and gain interest in solar energy products is critical to understanding how to best satisfy our market. Please feel free to comment below!

I don’t need to say much about the graphic below. The total amount of solar electricity capacity installed in the U.S. is nearly doubling each year. This is truly an exciting time to be involved in the solar industry!

Considering that Germany with a much lower solar resource availability has over FIVE TIMES the installed solar electric capacity of the U.S. and over TWENTY TIMES per capita, there is a lot of room to grow still!

Cumulative Solar Electricity Installed in the U.S. Through 2012.

Florida has some of the nation’s lowest installed PV Prices

I just finished watching to the webinar from the Lawrence Berkeley National Labs, “Tracking the Sun VI: An Historical Summary of the Installed Price of Photovoltaics in the United States from 1998 to 2012.”  The data definitely backs the trends we are seeing locally in Southwest Florida. Here are some observations:

• Prices have continued a downward trend over the last decade, but have leveled off in 2013. With photovoltaic (PV) prices starting to tick back up, installed system prices are likely to increase in the near-term (installed price changes tend to lag PV module wholesale price changes). This is exactly what we are seeing and what I expected – we have seen the bottom of installed prices for at least the foreseeable future, and price stabilization or even increases are on the horizon.
• There is a not much of a price benefit as systems get larger. The discount for a larger system is not significant. You can expect to pay a similar price per watt for a 4kW through a 10kW system and larger. This is echoed by what we are seeing in our cost of doing business. There are few economies of scale when installing larger systems. Fixed costs are low. Costs are mostly variable with system size. In fact, larger systems can result in higher costs per watt as switch gear gets more expensive, engineering costs increase, and job complexity increases. In addition, both local utility companies currently charge one-time interconnection fees for systems over 11,765 watts (DC-STC Rating). There is no interconnection fee for systems smaller than this.
• Florida has some of the lowest installed prices for solar electric systems in the country. In fact, prices tend to be around 15% lower than the national average for systems under 10kW. Southwest Florida has even lower prices than the state as a whole, at about 25% lower than the national average. As the report states, U.S. intra-state price variability exists, and it is often wider than cross-state difference.
• Third-party owned (leased, financed) solar electric systems dominate in some states, especially the states with high numbers of installations. Florida tends to be a “cash sale” state, and prices are much lower. Presumably this is because there is no third party financial institution involved in most transactions. However, it reduces the number of installations because fewer can afford the up-front cost of solar electric systems. The end result is lower installed capacity, but more value for the end consumer (better investment returns). 

As I listened to the hour-long presentation I felt substantiated in my assessment of the market, and I’m further convinced that we are providing some of the best solar energy values in the nation here in Southwest Florida. While we still can’t meet the rock bottom prices found in mature solar markets like Germany and Italy due to “soft costs,” the value proposition is still excellent here because of the ample sunlight we receive.

If you are interested in the full report, it can be found at the link below.

Tracking the Sun VI

This Washington Post article reports that the White House is installing solar panels this week. That’s a great move, and a great statement. I wonder if the Obama’s are eligible for the 30% Federal Tax Credit on the purchase.

I did notice one interesting point in the statement made by the unnamed White House official. They said that the  solar panels are being installed as part of an overall retrofit to make the building more efficient. I’m one of those annoying people that insists on always being accurate and correcting people that make minor factual, grammatical, and technical misstatements.¹ The point I want to make is that solar panels do nothing to make buildings more efficient. They simply change the source of the energy from the primary supplier to solar energy.

I know that ‘s being pretty nit-picky, but based on the presentations I give before groups, it’s clear that people don’t really understand how solar electricity systems interact with the home and utility grid. In reality, a building mounted solar electric system just produces power. It does not reduce the energy needed to perform the same function/work, which is the definition of efficiency that is important here. Efficiency upgrades would include lighting that uses less electricity (provided that the light output is the same or the functionality is unchanged), heating and air conditioning systems that use less electricity to result in a change in temperature, and insulation that results in decreased need for mechanical heating and air conditioning systems. These are things that reduce the energy required to meet the needs of it’s occupants.

In other words, adding solar panels to the White House is not “part of an energy retrofit that will improve the overall energy efficiency of the building.” It’s a retrofit that will shift reliance on the primary source of electricity to a renewable resource, albeit for a very small portion of the energy consumed.²

Don’t get me wrong – I think its an important message to send to the American people. The solar industry is one of the few thriving industries in terms of jobs, and the installation signals a shift to a new energy paradigm. Maybe we should call it “whitewashing(ton)” instead of greenwashing. Sometimes greenwashing is justified, and I think this is one of those cases.

I also found the “competitive bidding process” a bit funny for this 20-50 panel system. We’re talking about a $50,000 project.  The government will spend triple that on the bureaucratic process of managing the bidding. Oh well, they can just print the money needed in a few millionths of a second.

<sup>1. I can dish it out, but can’t take it, so please don’t dissect my blog.
2. I’d love to see the Obama’s electric bill. I guarantee that these solar panels won’t cover 0.1% of the building’s energy needs, but once again I applaud the gesture.</sup>

Energy Secretary Chu Announces Solar Panels on White House

One of my favorite solar electric systems to watch is located at a customer’s residence in Cape Coral. It’s a favorite because there are solar modules on roofs facing due South, East, and West. This provides an opportunity to validate that solar electric modules are best mounted on south roofs, followed by east, then west. That’s great news for us, because we are often faced with locating solar pool heating systems and solar electric systems on the same home. If there are clear east and west roofs, the solar electric system performs best on the east, and solar pool heating performs best on the west. Perfect!

Some people are surprised that solar electric panels mounted on the east roof perform better than west facing panels in Southwest Florida on an annual basis. The main reason is the cloudy and rainy afternoons we experience in the summer and early fall. Check out this system below. Over the last 7 days, the east facing panels have outperformed the west facing panels by almost 20%. In fact, the east facing panels have even outpaced the south facing panels. That’s not surprising given the typical summer rain patterns we see here. On 6 of the last summer days, the system as a whole showed decreased production later in the day when the sun is in the western sky.

Enphase Microinverter Solar Electric System in Cape Coral – Performance over the last 7 days.

Because microclimates result in varied weather in small geographical areas, it is hard to compare homes even in the same city. This home provides a unique opportunity to observe panels with three different orientations at the same location. Fortunately, the solar modules are virtually unshaded, providing a wonderful test case for us year-round.

You can view this public reference system here: https://enlighten.enphaseenergy.com/public/systems/NNQk126038

The Law of Conservation of Energy is a basic recognized law of physics, and one I occasionally forget when writing and speaking about solar energy. Solar power does not “create energy.” It simply converts energy to usable forms in our everyday lives. For example, solar thermal technologies move heat to where we want it. Photovoltaic systems convert solar radiation into electrical energy that we can use to power electronic devices.

If you catch me saying the phrase “create energy,” please pinch me or something. It’s a bad habit that I’m trying to break.

I was reminded about this as I spoke to an employee about how solar panels affect roof temperatures. Black panels on a roof can’t be a good thing, right? Well, solar pool heating panels can approach 85% efficiency, meaning that 85% of the sun’s radiation hitting them is transferred to pool water and the energy (latent heat) is moved into the pool. As a result, the roof under the panels is only subjected to 15% of the sun’s radiation (heat). I’m oversimplifying this, but common sense tells us that as we move heat from the roof to the pool, the roof underneath the panels should be cooler.

Similarly, solar electric panels, which are about 20% efficient with today’s commercialized technology, convert some of the sun’s radiation to electricity. Consequently, 100% of the solar energy landing on the solar panels cannot be radiated onto the roof’s surface.

I know some astrophysicist will send me an email about some obscure technical faux pas in the above analysis, but that’s okay. I’m not a physicist. The important thing to remember is that solar energy systems do not create energy – they just allow us to use the energy made available to us from the sun.

Enphase MyEnlighten on iPad

Enphase has updated its solar electric monitoring portal for system owners, updating the site to the new MyEnlighten design.

The new user-friendly design provides an amazing amount of information at a glance, including a cool new 365 day view that uses color to indicate the relative production on every given day of the year. This unique view allows drill-down reporting of energy produced for finer detail. As always, Enphase provides per-solar-module level performance reporting over time.

The old Enlighten site is being re-branded as Enlighten Manager, which continues to provide installers granular performance monitoring data and comparisons against expected results. Solar installers can dig into help customers maximize performance and can remotely manage devices that need attention. Enphase’s world-class tech support can further diagnose issues and remotely upgrade device software as needed.

Enphase is one of the first and the most successful microinverter manufacturer. They manufacture the industry leading M215 microinverter, and will soon release the new M250. Download a brochure below:

Enphase Microinverter Brochure

You can also view the performance of selected reference systems installed by Fafco Solar here.

Fafco Solar Enphase Public Reference Systems in Southwest Florida