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A metal roof with built-in solar panels is the most energy efficient and longest lasting solar roofing solution. A metal roof will usually last in excess of 50 years, and solar PV panels usually last 30+ years with minimal loss of efficiency or or electric power production. The combination of the two creates a one-time green roofing investment that will pay for itself over time, and then it will produce free electricity. Such a smart combination eliminates the chance of roof leaks, since there are no roof penetrations, and gives a homeowner piece of mind and confidence in their green metal roof.

Why go with a metal roof, instead of asphalt shingles:

Why would you want to install PV solar panels with a metal roof, instead of installing it on the existing asphalt shingle roof? The answer is very simple; asphalt shingles last an average of 15 years, while your solar panels should last at least 30 years. That means that even if you install your solar panels over a brand new asphalt shingles roof, you will have to remove the whole solar system in 15 years, replace the roof, and then put the solar panels back onto the roof. With the installation costs of a solar PV system being about $2 per watt, and an average solar system size of 3 KW, you will have to pay an extra $6000 (in today’s dollars, before any inflation is calculated) to reinstall your solar panels, and another $1500-2000 to
remove the panels, so that the roof can be replaced. With today’s average solar system price of $9-11 including solar panels, inverter, all wiring, rack-mounting system, permits, installation, etc.), the removal and re-installation price amounts to about 25% of the total solar system cost.

A properly installed standing seam metal roof will easily outlast any asphalt shingles roof by 3 time or more, and it will also outlast a warranty period on any solar panels. When your solar panels get old, and start producing less electricity than what they were designed for, you will have an option to either keep the old solar panels or install the new ones (as a side-note – average efficiency loss of a solar panel is 0.5% per year or 10% over a 20 year warranty period). All your infrastructure will already be in place, and you can simply swap the old solar panels for the new ones. You may also have to swap the charge controller / inverter. In 20 or 30 years, as technology progresses, the efficiency of solar panels and inverters will be much higher, and the cost per watt will be considerably lower. At the same time you will still have your metal roof, performing at 100% efficiency – being leak free and beautiful, that is.

Installing solar panels on a standing seam metal roof

Solar panels can be attached to a standing seam metal roof in two different ways. One is to use a thin film Solar PV panel laminated inside the pan of a standing seam metal roof – a so called solar metal roofing concept, when solar panels are integrated with the roofing material. The limitations of solar metal roofing include lower efficiency (per sq. foot or sq. meter) of the solar PV laminates. Therefore you would need double the roof area to get the same number of kW of a solar system. Also the size limitation of each solar PV laminate (18 feet long panels) make it impossible to install them on roofs with a roof run of less than 18.5 feet.

A better way to install solar panels onto a metal roof is to use S-5 clips or mounting brackets, specially designed to add adequate strength and support of rack-mounting systems installed on standing seam metal roofs. S-5 clops are made of cast aluminum blocks, with stainless steel tightening screws. S-5 clips are attached to the ribs or locks of a standing seam panel, and provide great pullout ratio, meeting and exceeding Miami-Dade county building code requirements for wind uplift.

S-5 Solar Panel mounting clamps allow for a quick and inexpensive installation of the solar rack-mounting system. Solar panels can be attached directly to the clamps, or to horizontal / vertical rails. The overall cost of such solar racking system is reduced from about $1 per watt, to about 50 cents per watt, or less. Also, you do not have to worry about any roof leaks, as there are no roof penetrations, and all mounting hardware is attached to the ribs of the metal roof panels.

You can also get a double tax credit for your solar roofing installation – Your first tax credit would be a 30% tax credit for solar panels, and and another one – up to $1500 cool roof tax credit. An average cost of metal roofing materials will exceed $5000 per roof, so you will be able to get a full 30% cool roof tax credit. With today’s metal roofing prices for steel standing seam ranging from $15000-20000, a $1500 tax credit will save you about 7-10% off your lifetime metal roof.

Every day real estate agents sell green to make green but few real estate companies put their money where their roof is. But this is exactly what Prudential Locations has done when it installed solar panels in 2008. Since their installation in 2008, the new 87-kilowatt photovoltaic (PV) system at the company’s Honolulu office have reduced CO2 emissions by an estimated 650,721 kg, and produced more than 382,000 kWh of energy.

The solar panels – which currently generate more than 136,000 kilowatt hours of clean, solar electricity each year – are just one way Prudential Locations is bringing to light its corporate sustainability initiative, which aims to reduce the company’s carbon footprint. In addition to installing the PV panels, elements of Prudential Locations’ sustainability initiative includes a paperless initiative where the agents submit contracts electronically, increasing use of recycled products, as well as recycling.

“We live and work in such a beautiful place that it only makes sense that Prudential Locations do what it can to be sustainable and care for our environment,” said Joe Segal, Prudential Locations online marketing manager. “By installing the photovoltaic panels at our Honolulu offices, we hope that we are able to set an example for other local companies on how they can make changes both big and small and be sustainable.”

The photovoltaic panels currently produce enough electricity to power 382 homes for one full year and are also helping Prudential Locations’ bottom line, saving the company 10 to 15 percent on its electrical bill each year.

The PV technology that Prudential Locations installed converts solar energy into electricity with minimal impact on the environment and offers “net metering” which occurs when solar panels generates more electricity than the building can use.

Installed by Hawaii-based company, Hoku Solar, the project has already created excitement amongst Prudential Locations agents and employees.

“It is a privilege to be able to work for a local company that demonstrates such a deep commitment to the environment and our community,” added Segal. “I think it really speaks to Prudential Locations’ values and our ability to stay at the forefront — not just for real estate trends, but in sustainability as well.”

More information on Prudential Locations and the company’s green initiatives is available at http://www.prudentiallocations.com/green.aspx.

The team at GreenDIYenergy has been active lately teaching impoverish communities how to harness solar power using homemade solar panels. Over the last year, their solar expert Brian Clark has conducted four free “solar workshops” in poor, rural communities.

What Have They Done?
Oct. 2008 – Nicaragua – 3 month trip to Nicaragua to teach local schools how to build solar panels, allowing students to continue learning after the sun goes down.
Oct. 2009 – South Dakota – 3 day intensive seminar at Pine Ridge Indian Reservation. With unemployment exceeding 80%, the solar seminar was aimed at transferring knowledge to empower the local people with electricity and potential job opportunities.
Nov. 2009 – New Mexico – 3 day intensive seminar at the Cochiti Indian Reservation. This trip focused on harnessing solar power through homemade solar panels, to power water pumps. This will allow the local community to expand their crops with irrigation.
Dec. 2009 – Uganda, Africa – 3 week trip to the Ugandan village of Mbale in Africa. The focus of this trip is to teach locals how to build solar panels for their homes, as most of the residents currently live without electricity.

Solar Power In Action
All of their solar goodwill trips are posted at www.SolarGoodWill.org . It’s amazing to read how homemade solar panels are affecting so many different communities. With the right knowledge and expertise, solar power can be harnessed inexpensively. Be sure to check out their website to see how they are using solar to empower some of the poorest communities in the world.

We have checked out many of these “DIY Build Solar Panels” guides online and the www.GreenDIYenergy.com product is the best. For only $50 you get a CD mailed to your home showing the detailed videos, guides and bonuses. It’s great to see that they don’t just sell good information, they also teach it to those who need it the most.

The first of four sets of PV has arrived. We unboxed them and dry assembled to see how it all goes together. The documentation on assembling the rack is pretty poor, as the diagrams do not exactly match the pieces shipped, and there is no documentation on aligning the panels onto the frame (pins in adjustable slots). It makes a difference which way the panels are oriented, wires up or wires down, as the slots are not centered, and no guidence is given.

Last night we measured and cut all the pieces for the battery box. In-place assembly should start this evening. More photo’s can be found in our photo album.

RENEWABLE POWER FOR AMATEUR RADIO (and other electronic devices)
by Larry D. Barr, K5WLF

About the author: Larry D. Barr is an Amateur Extra class amateur radio operator, first licensed in 1966. He is uniquely qualified to write on this subject, having lived offgrid for 19 months with the majority of his electricity provided by a Wincharger 1222H wind generator. Larry is a journey level electrician, an alternative energy systems designer and the former editor of Energy Self Sufficiency Newsletter. His pickup mounted, solar powered ham radio installation was featured in the American Radio Relay League’s “We Do That” video series and on their website. Currently employed as the Planetarium Manager for Tarleton State University in Texas, Larry continues to be active in renewable energy and looks forward to living offgrid again in the near future.

Because of my interest and involvement in renewable energy, I’m often asked by other amateur radio (ham) operators about the best way to run their stations on renewable energy sources. Most of these queries pertain to solar, or photovoltaic (PV), sources, but we’ll also mention wind and minihydro in addition to PV in this article.

The good news is that modern, solid state ham rigs lend themselves extremely well to renewable power. They draw relatively little current at a nominal 12 VDC, and therefore require fairly modest expenditures in generating devices.

The bad news is that hams who like the old vacuum tube (hollow state) rigs will not be able to power those old “boat anchors” without a serious layout of funds for PV panels or a much larger than usual wind generator. The old rigs simply draw too much current to be practical for operation on a renewable system.

So, let’s look at the practicality of running a modern, 100 watt, solid state transceiver like my Yaesu FT897D on a PV system. It’s easy to do – and at a relatively low cost for the solar setup.

First, let’s consider the power required to operate the radio. There are two distinctly different current requirements for the unit. One is the power required for the radio to receive incoming signals. That’s about one ampere (1A) at a nominal 12 volts direct current (12 VDC). Nominal 12VDC turns out to be somewhere in the vicinity of 12.6 VDC, for a fully charged 12 volt battery, to around 13.8 VDC which is the output of an average vehicle alternator. We’ll mostly stick with 12 VDC for this article just to make the calculations easy.

The other requirement is 22A while transmitting at the full 100 watt output level. Well, you’d think that wouldn’t take long to run down a battery, and you’d be right. But think a minute. We don’t transmit all the time. Actually, the ratio of transmit to receive in normal ham operation is right at 1:9. 10% transmit and 90% receive.

Now, we need to figure out how many Amphours (Ah) we’ll use per clock hour in normal operation. Amphours is the numbers of amps, the current, consumed over a period of one hour. It’s the way the battery capacity is rated. As I said earlier, normal radio operation is generally calculated at 90% receive and 10% transmit.

So, in 1 clock hour we’re consuming:
(1A X 0.9h) + (22A X 0.1h) = (0.9Ah + 2.2Ah) = 3.1 Ah

Figuring our 100Ah battery at 50Ah, because we don’t ever want to take the battery below 50% depth of discharge, we divide:
50Ah / (3.1Ah/hour) = 16.129 hours

Which is about 16 hours and 8 minutes from a fully charged battery. I run two 100 Ah sealed lead acid (SLA) batteries in my battery banks for a rated 200 Ah capacity and a ‘real world’ capacity of 100 Ah. That doubles my run time to about 32 hours and 16 minutes.

There are those who will disagree with me about my advice to never exceed 50% depth of discharge in a deep cycle battery. They are welcome to do so. And I will never loan one of those folks my batteries. Your batteries will last much longer and provide better service to the end of their life if you follow my advice. Each time a battery is drawn below 50% charge, it gives up a small part of its longevity. Personally, I can’t afford to replace batteries before the natural end of their life. So, I treat them well. My shack and pickup batteries are over six years old and still operating at peak efficiency.

I must mention here that manufacturers base the capacity ratings of their batteries on the assumption that the discharge will be made at a constant rate. That rate is assumed to be one twentieth (1/20) of the published Amperehour rating of the battery. In the case of our single 100Ah battery, the rate would be 5A. For our 200 Ah bank, it would be 10A. This relationship is called C (capacity) / 20. You’ll see it published simply as C/20 or ‘the C/20 rate’.

Any deviation from this C/20 rate, especially discharge rates which exceed it, will result in a different amount of power available from the battery. If we exceed the C/20 rate, the capacity of the battery will be less. In many cases, much less. It depends on the extent to which we exceed the C/20 rate of discharge.

In the case of our 100 Ah example, since our calculated rate of discharge was 3.1Ah/hour (or 3.1A), we were below the C/20 rate of 5A and should get at least the run time we calculated. However, if we were to exceed the C/20 rate, our run time would be less. How much less would be proportional to the amount above the C/20 rate that we imposed on the battery. If our discharge rate is below C/20, we may get a bit more. But let’s figure for worst case and not count on it. This phenomenon has been well documented by a gentleman named Peukert and his analysis of the effect is known as Peukert’s Theorem.

We should note, and must accept, that this does not indicate that the battery is faulty. It’s simply reacting in accordance with the laws of physics and chemistry that batteries operate under. To draw an analogy — if you bought a car and the manual stated that you could expect 25 MPG at 50 MPH, it would be unreasonable to expect that same mileage at 120 MPH. You’ve changed one of the variables in the equation and you can’t expect the result to be the same.

Now, let’s look at the PV panels and other gear required to support our FT897D on a solar electric diet.

My system consists of two UniSolar US64 amorphous panels rated at 64 watts each. They’re connected in parallel for a total of 128 watts. With the Xantrex C12 charge controller set at an output voltage of 14.2VDC – it seems high, but it’s right for the SLA batteries – that gives me about 9.01 amps to the batteries. Let’s just call it 9 amps. So, in one clock hour, I’ve put 9 amphours back into the batteries. That’s almost a 3:1 ratio of input to output.

Truth be told, I usually see about 7.4 amps, more or less, from the panels going into the battery bank. But that’s more than twice what I’m using and certainly explains why, on occasion, I’ve gone out on a radio mission with less than fully charged batteries, worked on the air for four hours or so and returned home with a fully charged battery bank. And all free, from Mother Nature.

My UniSolar panels aren’t available anymore. Unisolar has decided to dedicate their manufacturing capability to mainly Building Integrated PhotoVoltaic (BIPV) and has discontinued their line of discrete PV panels. We recently mounted a Kyocera 235 watt panel on our local ham club’s tower trailer, and if I were buying now that’s what I’d get for myself.

Let’s look at the total cost of a PV system to run the radios using the Kyocera panel.

The PV panel will run you about $375, the Schneider/Xantrex C35 controller with the CM digital display (recommended) is about $165, and a pair of PowerSonic 100 Ah SLA batteries will round out the system for $275 each or $550 for the pair. That’s a total of $1090 for the system. With proper care, the panel and the controller will last you for a lifetime. The life span of the batteries depends on you. I’ve been running mine for about six years now, and they’re still doing their job, and doing it well. If you abuse them, by discharging them below 50% capacity, or over or under charging them, their life span will decrease.

Now, let’s talk about wind power for a minute. If I were buying a wind generator today, I’d get an Air 30 turbine made by Southwest Windpower. It’s a 400 watt unit and has all the controller circuitry built in. At peak output, it’ll give you somewhere around 25 amps, and because of the integral controller, it interfaces seamlessly with a PV system. Cost is somewhere in the neighborhood of $600. If you live where wind is one of your most prevalent natural resources, you might get by with just the Air 30, but I really recommend a hybrid system that uses more than one source. Wind and PV is a great combination, for many times when the wind is blowing the most, the sun is obscured.

Minihydro is a wonderful power source if you have a year round watercourse on your property. If you don’t, just forget about it. My dream is to find a property with a year round stream on it, but unless I win the Lotto and maybe leave Texas (not likely), I’ll never find it. Don’t even fret over hydro unless you can provide your system with a reliable and continuous source of water. There aren’t many locations available with that resource and it’s best to not even think about it unless you already own it. If there’s a call for it, I’ll gladly write about minihydro at length in a future article.

OK. let’s summarize. I’ve explained how to calculate the draw of your radio. We’ve discussed the factors that control battery run time and battery life. We have talked about the initial cost of a PV system, and considered adding a wind turbine to the system. It’s easy to add other 12VDC devices, such as lighting or entertainment devices, to the system. Just do your calcs and ensure that you’re not drawing your battery bank below 50% capacity. Be sure to follow all appropriate wiring codes and make damn sure that your wiring is safe and overload protected. Enjoy the free energy that Mother Nature provides. ldb

Off grid info and components available at http://www.green-trust.org/products/

Discuss Amateur radio and alternative energy topics at http://groups.yahoo.com/group/Alt_Energy_Hams/

The rest of the PV panels have arrived. A total of 180 watts of PV in 15 watt modules, temporarily sitting in our yard, facing south, waiting for lumber to permanently mount and wire. I hope to get them wired in tonight, and mounted by the weekend. Still have not had the chance to put the battery box together. That was supposed to be last nights job, but the PV panels sidetracked me. All the lumber is cut to size, I’ve got the screws, so no excuse for not getting it done. Tonight looks good.

Other users of these panels:

ki4ilb

Jon’s system (grid tied with microsine inverters)

Do you live in the UK? Are you trying to decide if your site is appropriate for solar panels? What government incentives are there? What panel technology works best for you?

There’s a great site for prospective UK buyers of solar hot water & photo-voltaic power systems. http://www.solarpanelsuk.co.uk has online tools that help answer these questions, from siting a system properly, to selecting the correct equipment, to taking advantage of tax breaks and rebates. They will even help find you an installer if you need one. Check them out!

Our mission is to bring renewable energy to more homes within the UK and to help educate consumers on exactly how affordable renewable energy can be.

With our range of free tools, our users can explore the benefits and rewards that renewable energy can bring. To get started, click one of the buttons above to discover how much you can save or even earn from solar power.

If you are visiting us from overseas, why not check out our free iPhone and iPad app that works worldwide.

For further details click here to visit the Solar Panels UK website.

The Pole Mount for our new solar panels just arrived. The UPS driver took one look at the panels that were laid out, and commented as he handed me the boxes, “Toys for boys?”. Oh Yeh!

The pole mount is from Iron Ridge, and will hold up to eight panels, but only six panels of this size. Next year, when we get another six panels, we will put up another pole.

The pole is a 10′ piece of used telephone pole, courtesy of our local phone company. It has yet to arrive.

Jim Juczak’s power system was damaged by their recent house fire. A group of us went to help them rebuild various aspects from sheetrock to applying primer. My son Matt and I tackled upgrading and repairing the power system. Jim had built wooden frames for the 12 new solar panels. These panels are a bit different than the usual ones we run across. Each panel is a 45 watt, 98 volt open circuit amorphous panel. Matt and I built combiner boxes and wiring whips so that each frame will hold 4 panels wired in parallel, and a master combiner box that parallels the 3 frames, feeding the Outback MX-60 in the house. The house contains a 24 volt Trojan L16 battery pack.

Each frame has a small combiner box connecting the 4 panels with 12 gauge cable to a 10 gauge uplink to the master combiner box. The master combiner uplinks to the house with 6 gauge. See pics at http://ph.groups.yahoo.com/group/12VDC_Power/photos/browse/5156?c=

They bought a 40′ shipping container to put belongings in while the house is being finished, so we put a temporary pv system on that as well for internal lighting.

We go back next weekend to fix the wind turbine and install some ground lines for the panels.

From http://www.elektor.com/news/nano-rectannas-grab-more-energy-from-sunlight.2426887.lynkx:

Even the best silicon panels collect only about 20% of available solar radiation and they require additional devices to convert the energy to usable electricity. A new technique using nano-sized antenna arrays could theoretically harvest more than 70% of the energy in sunlight, but the technology required to build and test them has been lacking. These nano-antennas, called “rectennas” because they can both absorb solar radiation and rectify the radiation waveform to generate direct current, must operate at the frequency of visible light and be fabricated with the core set of electrodes just 1 or 2 nm apart.

A novel fabrication process called selective area atomic layer deposition (ALD) developed at the University of Connecticut offers a potential solution to this challenge. In a rectenna device, one of the two interior electrodes must have a sharp tip, similar to the point of a triangle. Using ALD the tip of the rectenna can be coated with layers of individual copper atoms until a gap of about 1.5 nm is achieved. The best that could be done with previous lithographic fabrication techniques was a separation about ten times the required value.

The gap size is critical because it forms an ultra-fast tunnel junction between the rectenna’s two electrodes, enabling maximum current transfer. The nano-sized gap gives energized electrons on the rectenna just enough time to tunnel to the opposite electrode before the potential reverses. The triangular tip of the rectenna makes it hard for the electrons to reverse direction, thus capturing the energy and rectifying it to direct current.

Read more:

http://en.wikipedia.org/wiki/Atomic_layer_deposition

http://en.wikipedia.org/wiki/Rectenna