Regarding this article, I think I’ve found a simple reason for this failure, and the reason will shock and surprise you.
In the article, a news report by TV station WFTS is cited:
WFTS News in Tampa obtained copies of the courthouse’s electricity bills and confirmed the savings are no more than about $2,000 per month. WFTS also confirmed the panels are reducing electricity bills by only 15 to 18 percent, instead of the promised 40 percent.
You can watch the news report here.
They say a picture is worth a thousand words, I’ve got one of those. First, look closely at the picture in the news story above…now look at this picture and note the arrow.
I think the government dufuses and the solar company missed the shading from the nearby tall building (the Hillsborough County Center Building), seen in the photo above which you can inspect yourself at Bing Maps here: http://binged.it/1tqPjnf
It looks like a little over half of the panels would be in the shade during the afternoon based on my comparison to the article photo, a larger version which exists here:
Source: http://www.naco.org/newsroom/countynews/Current%20Issue/10-18-10/Pages/OldMainCourthousesolarphotovoltaicproject.aspx
That afternoon shade will kill solar panel efficiency big time. The problem will be greater in the winter, at low sun angles, further reducing the efficiency of solar panels which appear to be placed flat on the roof, rather than tilted for maximum efficiency. In fact if you watch the WFTS i-team video, you’ll see that the panels are in fact laid directly on the roof surface. Here is a screen cap showing workers placing flexible panels flat on the roof:
The effect of array tilt angle on solar PV energy output may be up to 20% compared to that of flat installations, depending on latitude. Typical rooftop arrays with tilt look like this:
![Piscataway-Conackamack[1]](https://wattsupwiththat.files.wordpress.com/2014/08/piscataway-conackamack1.jpg?quality=83)
You can read more about tilt angles and panel efficiency here.
But the tilt issue is small compared to the shading issue by the tall building to the Southwest. using Google Earth’s timeline feature, I found an image from Dec 26, 2012 that shows the peak shading near the winter solstice, it also shows the solar panels in place. Clearly, the shadow will cover a significant portion of the solar panels on the roof for a period of time.
The next thing that needs to be done is a public records request to get the hourly solar power system output data over the past couple of years, it should be an easy matter then to note when the output drops significantly, and to line that up with sun angles and times.
On a daily basis, you can watch the real-time output page here:
Source: http://www.hillscty419piercepv.com/
Below the big dial gauge, if you choose “select gauge” and the “Interval 2-hour Avgs.” you’ll get a bar graph plot of solar output by hour, though there is no facility for getting anything but today’s data. From my observations, it seems that at this time of year, we get a bigger drop-off in production in the late afternoon than we should, which should be almost symmetrical with the buildup in the morning towards peak insolation. The afternoon production seems to have a larger gap.
It will be interesting to see what the public records request for the hourly solar power output data brings.
Full disclosure: I have a solar power system on my own home.
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A recent headline from the increasingly useless Chicago Tribune:
“Rules prevent solar panels in many states with abundant sunlight”
http://www.chicagotribune.com/news/nationworld/chi-rules-prevent-solar-panels-in-states-20140809-story.html#page=1
After reading the article, the headline is a complete lie. People can install all the solar they want (providing of course it meets local building codes).
But shucky darn if it ain’t just too expensive if it isn’t funded by taxpayers !!!
Absolutely, spot-on! The problem is all about subsidies and forcing others to take on the problems and costs of your decisions. The economics are just not competitive …. unless you use regulations to rebalance the playing field.
If someone wants to go solar, they should be able to remove their house or part of their house from the grid. Then there is no cost to the utility, only a reduction on its power sales as people go off grid. Same as when you turn off your oven, washing machine and power saw in the workshop. But it is the attraction of selling “excess” electricity at an above-market price, that makes the whole project attractive to the homeowner. Let them eat their own bread, I say; I don’t want to have to buy what they call cake.
Now that I’m thinking …. the Florida building SAVES only a small amount of money, but does that number include what they SELL to the grid? Perhaps that is in a separate account. Perhaps the project is actually very worthwhile in toto.
What interest is being paid on the capital cost of $1.2M. The payback with the $60,000 projected saving is 20 years (Not including interest) but PV panels do not last 20years.
average annual savings $27 thousand, investment $1.2 million. 2.25% return.
not enough to pay the cost of money, let alone maintenance and lifetime replacement. even if the output was doubled.
The payoff period seems to be longer than the predicted lifespan of the equipment. rofl.
That’d only take 44.5 years to pay off. Although with the way government is printing money, and the cap and trade that will eventually go into effect, that will be about 6 years….
Useful life is 20 to 30 years – so like all solar installations they can never pay back.
Germans are now making projections to go away from nuclear and toward coal but then be 100% alternative by 2050 when energy costs will consume 50% of the German GDP.
My understanding is that solar panels have to be maintained and the cost is not small. So we also need to know how that factors into the equation.
Yes, Ferdberple, even using your generous figures, SOLAR WILL NEVER BREAK EVEN. It is always a NET NEGATIVE ROI.
Using their figures: @ur momisugly an annual interest rate of 2.3%, the Present Value of $24,000/yr. for 350 YEARS is only about $1,043,000. And after that, the rate of return diminishes so rapidly that even in 1,000 years they could NEVER RECOUP THEIR INVESTED COST of $1,200,000.
What a scam.
Well, I just used the word “sk-a-m” (spelled correctly). And I’m in moderation. Sigh. (posted this for just FYI)
The “large building” is the county office building. It was built as part of a private, upscale office development that fell through and the county, under G Karl, a very competent administrator, acquired it on favorable terms.
It was, of course, in place when the solar project was built, but not when the courthouse that carries the panels was built.
TECO has a solar project at their Manatee viewing center at the Big Bend Power Plant. It is designed to set a baseline for what an optimized, fixed panel array can deliver. It is on pedestals about 20 feet above an open parking lot.
Among the findings is that there is about a 2% per month decrement due to dust. You would think with all our rain that wouldn’t be problem — but the “dust” may actually be salt encrustation as the project is on the shores of the bay.
Corrosion at the panel edges is already evident 4 years in.
When this project was built a survey was done. The primary solar usage in Tampa, which one would think would be a solar energy hotbed, is swimming pool heating. Black plastic tubes on the roof and a small pump turn you to be pretty cost effective. Solar electric — not so much, but then we have pretty reasonable electric rates.
The aforementioned Big Bend Plant is a four turbine coal plant. Fuel is provided by a 100 car unit train running to and from Ky a couple of times a week (seems like 500 cars when you are stuck waiting for it at the crossing on US 41). Most of our other plants are coal, with few natural gas conversions.
Far and away peak loads here are mid-summer Air Conditioning. This is when there is the most sun, so a well designed project might actually do some good here — certainly a more favorable situation that peak loads on winter nights. Can’t make the numbers seem to work though, especially in the low government subsidy environment that is Florida.
How many of those plants will be affected by the upcoming EPA rules? In Missouri, we have mostly older plants and it’s not looking good.
I can attest to the efficiency of the solar pool water heating in central Florida. It can easily take a 10 meter pool to we’ll over 90 F and a hot tub to 110F. Although that is not entirely electrical power free, as the pool circulation pump needs to be running.
Solar hot water is a completely different bird than photovoltaic, with water you have a energy storage medium.
Looks like a great DYI episode with that guy who comes in after the last remodeling company had screwed things up. I love to hear him tear the heart out of the job the last company did.
Mike Holmes? Or is that just in Canada?
I can’t imagine that a public works project like this didn’t have a Professional Electrical Engineer provide stamped drawings. Did they raise the issue? They should have. Some FOIA might shine some sunlight on these panels. Officially or unofficially, it’s probable that the engineer was told to not ask any questions.
I’m surprised that the government doesn’t require the building that is blocking their light to be taken down or pay for the lost power. /sarc
Amazing incompetence. No one bothered to check to see how much actual sunlight and power they could get before building that white elephant? Must have used a climate model instead.
Barry, that tall building is the “County Center” building, so they’d have to sue themselves to get reparations.
http://www.emporis.com/building/hillsboroughcountycenter-tampa-fl-usa
Don’t give them any ideas. It wouldn’t surprise me a bit to find out they did sue themselves… and we’ll be paying for both sets of lawyers out of our taxes.
Anthony,
Maybe they can install some wind powered lights on the offending building and aim them at the panels. This type of idea makes sense to many people, lets call them idiots.
It would seem prudent to install a photometer first, followed by a small pilot unit to verify that the project is indeed feasible. Failing that, how about a money-back guarantee from the contractor if performance falls below specs?
Why didn’t the installers make a note that it sure was nice working on this roof, as every afternoon it was shaded and much cooler?
The power drop is particularly bad if the panels are tied together at the panel output. Using micro-inverters on each panel allows the unshaded panels to output full (sun angle and temperature limited) power instead of affecting the whole array output caused by only a part of a single panel being shaded.
Max power rating of a solar panel is measured at STP conditions with the sun angle at 90 degrees. From there the output power drops as sun angle, temperature, age, dirt and shade all take their toll on output.
A Comprehensive Review of Solar Access Law in the United States by Colleen McCann Kettles, 2008, found that in Florida, based on Caton & Kettles, 1980:
California’s Solar Shade Act does not apply in Florida.
And, needless to say, even if that building were privately owned there would be no cause of action because it was THERE when the solar panels were added. When we added solar panels to our house (thanks to the government subsidies), we took down a tree that would have shaded the roof. This is just common sense.
So…you took down a tree that provided shade in summer to produce a little bit of electricity that probably won’t cover the increased AC costs from the increased lack of shade?
Government 101 – Tips on Installing Solar Panels in Shaded Areas
Government 102 – Tips on Using Eminent Domain to Justify Demolishing Buildings Shading Solar Arrays
This time of year in Florida, we get frequent, almost daily, afternoon thunderstorms.
I considered that, and as I’ve watched this over the past week, I also watched thunderstorm/cloud building from the webcam here:
http://www.myfoxtampabay.com/category/235614/downtown-tampa-florida-live-webcam
The building producing the shade (Hillsborough County Center Building) is the rightmost one in the image.
We need a compass bearing on photos or time of day for the photo with shadow.
What happens if you get a lightning strike on your panels and it’s wires? Picture?
As you probably know, afternoon thunderstorms are routine in the Tampa Bay Area from early June through October. It gets quite dark and rains buckets on most days. The cloud cover probably averages several hours/day during July and August.
If this doesn’t work in Tampa, imagine how bad it is in Ottawa (Ontariowe) Canada. They have been installing solar panels on the roofs of schools here — promising similar types of cost savings. Of course trying to verify the results (how much money we are losing) is difficult. There is one school that, for the time being, has a portal for monitoring the performance: a 10 kW system that for the past 30 days has produced 1,382 kWh — saving $1,108 or 326 lb of CO2. Pretty pathetic return since this is the summer (peak performance season) and the school is closed (so what did they really save). This system was installed in November 2011 (cost unknown) and has produced 32,000 kWh and saved $25,000 — what a scam!
They do it for the same reason Hillsborough did it: politicians want to get Green creds. The money doesn’t matter – it’s not coming out of their wallets. The politicians probably received Green creds, so I’d say the projects were successful.
I am puzzled by these numbers. Who is claiming a $25K saving? Claiming this amount for 32000 KWH implies a rate of $.78 per KW>
It is from their portal…I didn’t bother to do the per kWh calculations since the amount was so low. But now that you point it out: our retail cost in Ontario is about $0.13 / kWh; wholesale is $0.05. What these scamsters seem to be promoting is the savings based on the amount they get paid based on the FIT for solar which was around $0.78 when their contract was signed…unbelievable.
You would need to know what peak demand (kW) savings are estimated for lowering the demand ratchet before you can take the rest and divide the remaining kWh. Demand penalties can be significantly higher than the summation of the kWh.
I like to say, “Humans have much the same capacity for intelligent thought and rational decisionmaking as chickens have capacity for flight: we can do it; we don’t do it often and we don’t do it well, but every once in a while we get in a gorgeous soar and, hot damn! we think we’re eagles!”
This is one example of that.
If you’re gonna solar — personally, I hate open parking lots; I hate having my car turned into a solar cooker. Panels mounted (with tilt; I ain’t no engineer and even I know that one) to shade a parking lot, even if it didn’t produce much power, would spare my car’s A/C a bit of strain and I would be very grateful.
—-
As to solar access law — any lawyer serious about his work can find a counter-precedent to just about anything. The verdict goes to whichever side has the better “performance artist” for a lawyer. In the right (or wrong) hands, there is pretty much no such thing as “what the law says”. Excellent article reprinted here:
http://www.copblock.org/40719/myth-rule-law-john-hasnas/
The US Dept. Of Veterans Affairs spent $57.6 Million installing solar parking lot covers at VA complexes around the nation.The Oklahoma City VAMC’s $4.6 Mil solar parking install has lifetime warranty as part of cost, for the full 20 yr life of the solar panels. Published figures for cost savings to date, show the installation will pay for itself in as little as 45 years, but the panels will degrade with time, while per Kw prices will rise.
OKC is famous for high winds and knockout hail, but that’s ok, many Vets are adept at hittin’ the dirt when the shrapnel starts flying.
she is exploring paying cash to buy one outright for three of the cottages she owns. The cost: $106,000.
==============
It will cost the homeowner about $1000+/month to borrow $106,000 and pay it back over 10 years. A lot more if you factor in maintenance. You can buy a lot of electricity for $1000 per month, and if something goes wrong the power company pays for repairs.
The leasing arrangement works because of taxes. The leasing company gets to deduct the cost of the lease at their corporate rate, something the homeowner cannot do. If your large business corporate rate is 50%, then the taxpayer is picking up 1/2 the cost.
And the fact that the power company is NOT being forced to buy expensive, subsidized power form the homeowner.
It’s all about the tax credits
Decades ago PNM installed properly latitude angled water circulating panels on their new building in Albuquerque. I figured during the summer afternoons the cars in the parking lot south of the building would get over 140 F in the reflected light. Last time I was through town, the panels are all gone, as are, I presume, the absorptive chillers and water storage in basement. Money plus politics = deafness.
UV eventually degrades the panels and they disintegrate. The home we bought had solar on the pool that turned into a roof sprinkler after about 3 years, which was ~10 years after install.
Concerning the Dec 26th photo, it is late afternoon. December temps in Tampa do not require much A/C so it is more relevant that these panels work when they are needed most, April- Oct. I am not defending this array but Tampa has a latitude of approx 29 degrees N so during summer the Sun is almost directly overhead. Shading shouldn’t be a problem as much then. I think the real issue is that solar panels never produce the amount of power as advertised and are not cost effective. But what the hell, it was taxpayer’s money so nobody cares and it made County officials feel good about themselves for helping to save the Planet. Perhaps those using the building should be required to use only what is produced by those panels without supplementation from other sources.
The PV panels are flexible panels as well. The rigid panels are about 18% efficient. The flex panels are about 6%.The installer was smiling after that job.
@ur momisugly $2000 savings a month, that’s 50 years to pay off the 1.2 million dollar cost. That building won’t even be there in 50 years. I know because I live 20 miles from there. We like to rip buildings down & rebuild down here in Florida. It’s cheaper than fixing most times.
OK, so maybe governments aren’t too good at solar power. Maybe they should try something else like… oh, healthcare. /sarc /snark /Tampa-jump-the-shark
(Headed to Tampa Bay area next February as a climate refugee escaping Catastrophic Anthropogenic Global Warming. The hot is too cold for me. Will swing by courthouse in person just for the belly laughs. Mrs. H.R. has pre-approved the side trip. Need protest slogan suggestions for my 12″x18″ cardboard sign. Graphics limited by IHOP crayon selection. That courtyard looks like a nice place to sit for an hour or so while swilling an ice-cold carbonated soda. Might as well hold a sign while relaxing.)
Thunderstorms are not without value – they clean the solar panels, allowing greater solar radiation absorption.
Tampa is at 28 degrees latitude and laying the panels flat would have probably reduced
power obtained by less than 12 % from optimal, and tilting would have added cost to the system – providing
the structures to tilt the panels is not free. However, it’s likely that tilting would also provide greater
air circulation beneath the panels, allowing for greater panel output (panels lose efficiency when
they get hot). If the major losses occur in the winter due to greater shading as a result of lower
sun angles, then the optimal tilt angle for a fixed tilt array (as is the case here) will change and be
biased more towards optimizing summer performance, since that’s when the most radiation is received.
From my rather extensive readings of solar panel systems, people often have exaggerated beliefs in
how much power they will get. As I recall, a panel system lab rated at 6KW, will likely produce a max
output much closer to 4 KW (panels have two output ratings – go by the lower one). And the power inverters (which change the direct current output by the panels to AC current) can cost about as much as the solar panels themselves these days – panels have come down in price, while inverters (especially micro inverters) have gone up in price.
Good points,
I wonder how much consideration is given to high winds during Hurricanes or significant tropical storms especially in FLA. Are insurance rates increased for solar roofs or are they even covered?
I know that many homes in NJ had roof damage due to Sandy, which was not even a Hurricane as it struck NJ. Also it seems that tilting would further exasperate the problem to stay on the roof. Also how expensive is it to repair a roof with panels in place? I would never put solar panels on an old roof as President Carter did, which had to be removed when the roof required replacement. DUMB!
Another (dumb?)question,
When the solar panels blow off the roof as will happen some day in Fla, is there any Hazmat considerations for clean up?
Perhaps they could have installed Sun-tracking panels in an appropriate sunny place. However, I’ve read that very high winds, such as during a hurricane can damage upright panels.
Did they choose light weight panels because of the building’s design? Does flat placement that provides some sun early-to-late compensate for a tilted and fixed placement that restricts sun early and late?
The nearby tall building (the Hillsborough County Center Building) should have solar panel windows and sides. Morning and evening the E & W sides get more direct sun and in the low sun season the large side gets more direct sun. (More shading also, but, they are using OPM and it’s the gov’s good intentions that matter.)
———————————-
Your own project, AW, continues to look good. I ran a few calculations about 10 years ago and again when you first explained your setup. Our electrical rates in rural Wash. State with hydro and latitude of 47o N make for a non-economical situation. One new house a few miles away has been built with full-roof solar. I don’t know the economics of that.
Sun trackers have become uneconomic in 2008 due to falling panel prices – mechanics of trackers stayed constant in price. Since 2008 it’s more cost effective to increase the number of panels instead of buying, installing and maintaining the tracker system.
Oops! That should be 47° N.
Yes, but think of the children!
/snarcasm
rakman August 30, 2014 at 7:31 am is correct… shading has a very negative impact on PVC production. Any unit whose voltage drops significantly below the system average ceases to add current to the system and can potentially create a sink rather that a source. It all depends on the way the units are connected and of course it is more expensive to provide for the greatest possible granularity and reverse current protection.
I suspect that this system suffers not only because it was installed flat on the roof and is shaded by the nearby tower, but also because equipment on the roof will partially shade panels and thus render those shaded panels ineffective (see the tilted panel photo for an installation which takes this issue in proper consideration). This is a lesson the boating community learned decades ago but the county is just now re-learning the hard way. Perhaps county officials should have strolled to a local harbor and talked to a few boat owners about such things before squandering a million or so of taxpayer money.
BTW, there is another issue with an installation flat on the roof. Depending on the cell design, this will often lead to much higher cell operating temperatures and reduced life. I will also be interested to see how long the cells survive the repeated thermal shock induced by cold rain showers after several hours of baking in the Florida sun. Ask any Floridian who bought a new German car with clear coat paint in the 1980s and they will be familiar with thermal shock damage.
How much do you have to pay for a diode where you come from?
Solar panels ARE diodes.
The problem is, one panel delivers approx 50V; you string about 12 of them in series to get 600V for efficient DC to AC conversion (might also be 700, 800, depending on inverter design). If one of the 12 is shaded the voltage breaks down at that panel and drops to 550, wrecking the efficiency of the conversion.
Micro inverters work on a single panel but are overall more expensive because you need such a lot of them.
Yes they are made of gallium arsenide for the most part. All PV devices have a half life like all semiconductors – that is the time that they are only 50% efficient. Each day they produce just a little less than the day before or the year before. Again adding to the total design cost and the required overdesign if you want 20+ year set KWH output.
profitup10
August 30, 2014 at 11:41 am
“Yes they are made of gallium arsenide for the most part. ”
No; silicon for all the non-thin-film (18% efficiency) solar cells.
Traditional PV cells as described you are referring to the new thin film which has problems also.
There are three main types of thin-film solar cells, depending on the type of semiconductor used: amorphous silicon (a-Si), cadmium telluride (CdTe) and copper indium gallium deselenide (CIGS). Amorphous silicon is basically a trimmed-down version of the traditional silicon-wafer cell. As such, a-Si is well understood and is commonly used in solar-powered electronics. It does, however, have some drawbacks.
One of the biggest problems with a-Si solar cells is the material used for its semiconductor. Silicon is not always easy to find on the market, where demand often exceeds supply. But the a-Si cells themselves are not particularly efficient. They suffer significant degradation in power output when they’re exposed to the sun. Thinner a-Si cells overcome this problem, but thinner layers also absorb sunlight less efficiently. Taken together, these qualities make a-Si cells great for smaller-scale applications, such as calculators, but less than ideal for larger-scale applications, such as solar-powered buildings.
Promising advances in non-silicon thin-film PV technologies are beginning to overcome the issues associated with amorphous silicon. On the next page, we’ll take a look at CdTe and CIGS thin-film solar cells to see how they compare.
There are health concerns with the use of cadmium in thin-film solar cells. Cadmium is a highly toxic substance that, like mercury, can accumulate in food chains. This is a blemish on any technology that fancies itself part of the green revolution. The National Renewable Energy Laboratory and several other agencies and companies are currently investigating cadmium-free thin-film solar cells. Many of these technologies are proving themselves to be just as efficient as those that require cadmium.
So how are these next-generation solar cells manufactured? Read on and find out.
Gallium arsenide (GaAs) is a compound of the elements gallium and arsenic. It is a III-V direct bandgap semiconductor with a zinc blende crystal structure. Gallium arsenide is used in the manufacture of devices such as microwave frequency integrated circuits, monolithic microwave integrated circuits, infrared light-emitting diodes, laser diodes, solar cells and optical windows.[2]
GaAs is often used as a substrate material for the epitaxial growth of other III-V semiconductors including: Indium gallium arsenide, aluminum gallium arsenide and others.
“Traditional PV cells as described you are referring to the new thin film which has problems also.”
No, traditional non-thin-film PV cells are silicon.
“One of the biggest problems with a-Si solar cells is the material used for its semiconductor. Silicon is not always easy to find on the market, where demand often exceeds supply. ”
Not since the big price decline since 2008 – which was caused largely by massive new silicon fab capacities coming online.
I manufactured those for 30+ years . . all technologies have and use doping and heavy metal or other toxic items in the manufacturing process and the disposal process. There in no such animal as a pure silicon semiconductor device. The silicon is a substrate to deposits metals and to dope with compounds creating junctions. Read the link I provided and it will show a many layered structure.
So, how old is that roof they installed this array on? If you get 15 years out of any roof in Florida you’re doing good.
By the looks of the installation methodology, one tropical storm and most of those panels will reside in a new location.
This gives the word incompetent a whole new meaning.
The roof pic from my phone, isn’t a white roof. The panels output will be reduced further as the roof surface temps climb on warm, sunny days.
There was a very interesting article here 4 days ago introduced by AW, which involved the concept of EROI , or EROEI, Energy Return On Energy Invested , where it has been proposed that power plants should achieve , over their lifetime, a figure of at least 7 , to give back to society the resources used in constructing the power plant.
It seems an obvious way to grade projected conventional or “green” energies , provided one’s premise is that the existing quality of life throughout the society is to be maintained.
If it is permissible to equate energy with money , then the EROI figure for this installation , over 50 years life is 1, or 0.4 if Bobby Davis is correct in predicting the building’s demise after 20 years . To compensate society for this installation it should be generating a financial return of at least 14% annually, not 2% .
Of course one could artificially increase the value of the power generated , but ultimately society would suffer.
Or you could argue that this is just one small installation and that much larger installations elsewhere compensate with much larger EROI – which no doubt is true . However might it not be useful if planning authorities made more use of the EROI concept.
In the old days in industry (ie the old days when there was industry in Britain) we called it cost effectiveness
but it is basically the same concept surely but embracing society as a whole and not just an individual company and its shareholders.