13 Dallas Habitat for Humanity Homes Get Solar Roofs

To demonstrate the power of the Texas sun and the potential of solar energy as a big part of our energy supply, SES 21 USA has joined with Habitat for Humanity, Bosch Solar Energy, Schletter Mounting Systems, and SolarTek to make a great charity project come true.

13 Habitat for Humanity houses in Dallas are going to receive free solar energy systems on their roofs. The complete solar energy system consists of four panels and are estimated to produce about 1291 kWh of free electricity annually. Customers of SES 21 USA who have used Bosch Solar Energy panels on their installs in the Dallas / Fort Worth area told us that the power output is quite likely to be 10 to 20 percent higher than the estimation.

During a first educational evening 13 families were provided information about solar energy in general and how solar systems could help reduce their electricity bills.

The installation is scheduled to take place shortly.

Chet Boortz, CEO of SES 21 USA, commented

It’s a privilege to work in cooperation with an organization the stature of Habitat for Humanity.  Dallas Habitat does such outstanding work and builds these homes to exacting efficiency standards.  The addition of even small-scale grid-tied PV systems provides meaningful savings to homeowners that often pay the highest electricity rates in deregulated retail markets.   It’s a perfect fit.

Original Article on ses21usa



Solar Design Customized to your Home

Quite often we get calls at SES 21 USA from homeowners or installerswho are struggling with some design issues: what to do about trees thatshade or how to handle odd pitched roofs.  A number of times we haveseen people assume that they are not candidates for solar and give upquickly on the idea.

Rooftop in South Texas

We recently had a resident call in with a bit of a tricky roof. Asyou can see in the photo  his roof has many different pitches and thegables which cause shading in the late afternoon.  A roof mount wasdefinitely an option but the installer and customer decided on thisground mount system. The customer had the space for it, unobstructed bytrees or other buildings. Plus he can really maximize his ability toproduce solar power with this ground mount system. Did we mention the home is in very sunny South Texas!

Here is a photo of the final system designed with Schott 230’s and Kaco inverters!

South Texas Ground Mount

Congrats to the homeowner and the installer for designing such an efficient and practical  source of energy.


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SES 21 USA – New Website is Live!

Howdy folks,

Our new website is online! Check it our on

What’s new?

Not only an update on the design and our corporate logo was reasonfor the change to the new look. The new website is more powerful, moreintuitive and helps solar installers find information fast.

Use the live-chat feature to get quick answers to your questions or find the person you would like to talk to in our team directory


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Is The Natural Gas Industry Overestimating Supply?

So the natural gas industry would have you believe, there is no needto fool around with renewable energy . . . after all, we have a 200years supply of clean burning natural gas to generate all of theelectricity we need to meet U.S. demand.  Oh, that is really comforting . . . we will talk again in 200 years.

The natural gas production, of course, comes from fracking tight shale formations, wherever they exist, with a toxic concoction the ingredients of whichcannot be disclosed, because ingredients are a trade secret!  Now, withover 10,000 wells ‘drilled’, production data from shale formations are beginning to suggest, it’s going to be a long, expensive, and very dirty 200 years.

It’s easy in the oil patch.  We used to explore for oil and gas, nowwe simply manufacture it.  Just find a gas bearing tight shale from Texas to the Adirondacks; drill into the shale formation; kick out with four or five 5,000 feethorizontal well shafts . . . and frack, frack, frack . . . and thenproduce, at least for a few years.

Every well is a winner (a promoter’s dream).  The production declineis dramatic, but it does not matter, just keep drilling for 200 years . . . it’s good for industry, but maybe not so good for clean air and water.

Honestly, it’s difficult to predict natural gas production from tight shale formations . . . every well is different; and maybe it’sexploration after all.  Some wells are highly productive, many more arelaggards.  But every well leaves a long-lasting footprint.

Here is what is not difficult to predict: the sun will rise everymorning, again and again.  We have plenty of empirical data andevidence.  We can make this prediction not just for 200 years butperhaps another 2 to 3 billion years for our marvelous planet Earth.And, with each sunrise comes an unlimited supply of free and clean solar energy.  So, what is the holdup?

Call your state and federal representatives to advocate solarenergy.  They will be busy having lunch with lobbyists, but callanyway.  Leave a message.  Remind them that it’s 2011 not 1911, and it’s time to take a stand for reliable, sustainable, solar electricity.

THEN, make some noise; install a grid-tied PV system on your home orbusiness.  PV solar distributive electricity is affordable and economictoday.  It’s scalable (a small system works very well), and you do notneed to frack sunlight with a secret toxic concoction.

There are no trade secrets – it’s light from light, how cool isthat?  Solar electricity is a ground up popular movement.  This is theonly noise your politicians will here.  It’s time to get started.

Chet Boortz, CEO


[The comments, positions, and opinions stated above are my ownand may or may not represent those of SES 21 USA and its affiliatecompanies.]

Image: NYT – Overestimating Natural Gas Production – Source: Art Berman, Labyrinth Consulting Services

Original Article on SES21USA

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Solar Fest San Antonio

SolarFest San Antonio - SES 21 USA booth

Solar Fest San Antonio! a 100% renewable energy powered event

The show was premier for our 16 foot demo roof. Displaying a complete Schletter mounting system and Schott Solar as well as Bosch Solar Energy modules, the demo-roof offers a great way to see and touch componentsof a solar PV installation. Visitors could touch inverters (KACO blueplanet xi-series) and learn about our brand new standardized PV solar systems for residential slanted roofs.

Additionally, we brought a Schletter WS WindSafe Roof-Top Rack System for Flat Roofs (picture: left).

Thanks to the whole team of volunteers from Solar San Antonio!

Hope to see you soon at the next solar event!

Original Article on ses21usa

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New Design Helps Bosch Solar Break World Record

Bosch SolarEnergy announced that Bosch silicon cells have achieved a world record.The independent calibration laboratory at Fraunhofer Institute for Solar Energy Systems has confirmed that a degree of efficiency of 19.6percent has been reached for Bosch monocrystalline solar cells*. Normally, a silicon-based screen printed solar cell will achieveefficiencies of 17 to 18.5 percent. The output of the cells can reach an outstanding 4.73 Watt peak.

Bosch Solar Energy has been working on these new record-breaking cells for quite some time.The design structure on this new altered cell is referred to as PERCwhich stands for “Passivated Emitter and Rear Cell”.  The rear side ofthe cell as well as the front was optimized for the solar cells’ optical and electrical properties.

An immediate practical application for these optimized cells is thatthe cell’s performance is improved under weak lighting conditions andincreased ambient temperatures. This means a higher energy yield forsolar consumers even during winter months or overcast days.

Most consumers are familiar with Bosch power tools or homeappliances. Installers and consumers alike should familiarize themselves with Bosch Solar. Founded in 1886, Bosch is a worldwide company and amarket leader in patents. If you have a twenty-five year warranty onyour solar panels you’ll want a company that you know will be around for a long time!

For more information on Bosch Solar Energy please click here.

* monocrystalline solar cells with screen-printed metallization in 156 x 156 mm format.
   For full Bosch Solar Energy press release click here

Original Article on ses21usa

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PV Economics

The purpose of this Economic Series is to demonstrate with real numbers and basic analysis that an investment in a grid-tied PV system for home or business is a very economic proposition.  Now!  Yes now; not someday in the future but at the present.

In these writings, I have discussed important variables in determining a present value rate of return:

  • PV as an avoided cost
  • PV and residual value
  • Payback is the wrong metric
  • Determining electricity production from your PV system
  • Calculating the value of your electricity production
  • Performing the present value rate of return calculation
  • Grid parity is here!

None of this analysis is based on local incentives, rebates, feed-inor performance tariffs, REC’s, and certainly not on any socialcost/benefit analysis . . . just simple numbers.  There is oneexception; I do consider the beneficial 30% federal PTC or ITC forresidential and commercial PV installations.

I hope in the process, I have made PV economics more approachable. You should not simply rely on canned PV calculators to make yourdecision; understand the basics, and think through the analysisyourself.

Here are my assumptions and economic results for a 1.84kW (8 Schott 230W modules) residential installation in Fort Worth, Texas:


  • A 1.84kW grid-tied PV system
  • Fort Worth, Texas location
  • 180°  azimuth, and 32.9° tilt
  • PV Watts power calculation (77% derate factor)
  • $5.00/W installed costs
  • 30% personal tax credit for installed costs
  • Inverter replacement allowance at year 15
  • 12.02¢ kWh electricity costs (average U.S. residential rate, EIA, 08. 2010)
  • Efficiency loss based on module warranty (20% after 25 yrs.)
  • After FIT (avoided cost) calculation (28% marginal tax rate)
  • Residual value at 25 years: 10X annual savings
  • All cash; no leverage
  • Twenty-five years present value rate of return
  • NO REBATE !!

IRR calculations graph
*These are the primary variables for determining a present valuerate of return for your PV system.  Your actual return will be more orless depending on site characteristics and your actual systemperformance.  Remember, Quality Counts!

I recently attended a North Dallas Chamber of Commerce Energy Forum with a panel comprised of local utility executives.  TheChairman of Atmos Gas, a large Texas-based natural gas utility, whileexpounding the virtues of producing natural gas by fracking tight shalerock formations from South Texas to the Adirondacks Mountains of NewYork, assured the audience of a 100 year supply of natural gas forelectricity generation.  Really, 100 years?  In the Q & A, whenasked about renewable energy, the notion was summarily dismissed with an authoritative response that renewable energy was ‘5 or 6 times’ moreexpensive than conventional resources.  Really?  Mr. Chairman, do themath please.

Chet Boortz, CEO


[The comments, positions, and opinions stated above are my ownand may or may not represent those of SES21 USA and its affiliatecompanies.]

Original Article on ses21usa

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How do you Value the Electricity Produced by your PV System?

OK, based on the previous writing regarding PV system production, you now have a 40 year estimate of theelectricity to be produced from your PV system.  That’s right, 40 years!

It may be longer.  In a long-term study by the Fraunhofer Institute, Schott modules achieved over 90% of their original performance after years.  25 years with Schott modules, and you are just getting started!  Your PV system is a long-terminvestment – just like your home or business.  Be cautious of someonewho advises you otherwise.

To determine an annual economic value or income stream for theelectricity produced by your PV system, simply multiply the annual kWh’s produced by an estimated electricity rate for each year.  This is aforward-looking estimate, so have some fun with projections.

Here are two things we know:

  1. A good place to begin is with your current electricity rate.  That’s year one.
  2. The rate will go up or down every year.

We know from historical reference that electricity rates likely willincrease over time.  What are the variables that will impact rates? Fuel cost for generating electricity, transmission and distributioncharges, taxes, surcharges, inflation, environmental impact, and more.

So make it simple.  Consider low, medium and high forecasts for anescalation rate for electricity prices.  Maybe: 2%, 3%, and 4%.  Nowassign a probability of occurrence to each:

Electricity rate escalation Probability Product
2% (low) 25% .50%
3% (medium) 50% 1.50%
4% (high) 25% 1.00%
Escalator 100% 3.00%

Perfect, you have just completed a probability weighted analysis offuture electricity rates.  It’s your own forecast!  If it doesn’t feelright, do it again!  This is your analysis!

Use this escalator to compound the first year’s rate for 40consecutive years.  Multiply the adjusted rates with the electricityproduced in each year.  Now you have a 40 year forecast of economicbenefit or value stream from which you can determine a present valuerate of return for your PV system.

If you are looking for some references for historical energy and economic data, consider the Federal Reserve Bank and the Energy Information Agency.  Caution, you can get lost in the data!

Remember, if your PV system is for a residential property, the monetary benefit of a PV system is not income; it is Avoided Cost.  You pay income taxes and FICA on income; you pay no taxes on avoidedcosts.  So for purposes of calculating and comparing an after tax rateof return, you should gross up your PV benefit using your marginalincome tax rate.

For instance, if your benefit in year 1 is $300 and your marginal tax rate is 25%, your before tax benefit is:

$300 / (1-.25) = $400

Of course, this is not tax advice.  Check with your tax counselor.

Next, we will use the 40 year stream of economic benefits to determine a present value rate of return.  Easy!

Chet Boortz, CEO


[The comments, positions, and opinions stated above are my ownand may or may not represent those of SES21 USA and its affiliatecompanies.]

Original Article on ses21usa

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Calculating PV Return

Calculating the rate of return for you PV system does not need to be so mysterious.  Forget the calculators, let’s do some simple math.

We need to determine the benefit or income stream from the PV systemover a certain period of time (25 to 40 years) and then calculate apresent value rate of return (Internal Rate of Return) which includes the initial capital investment.  This is the wayinvestment decisions are made, so why not do the same for your PVsystem?

Remember, payback is a misplaced metric!  What if your PV system has a payback of 7 years but an economic life of only 8 years?  Oops . . . not good thinking!  PV is a long terminvestment, and so is the economic return.

So, the very first step is to determine how much electricity your PV system is likely to produce.

Your best resource is PV Watts

PV Watts is a performance database developed by the National Renewable Energy Laboratory (NREL) to provide performance estimates for grid-tied PV systems.  It is incredibility easy to use:

  • Click on your state
  • Click on a nearby city with similar topography
  • Under PV System Specifications . . .
    • Enter the system size (DC Rating), and
    • Enter variables for the AC to DC Derate Factor, Array Tilt, and Array Azimuth Factor only if different than the default settings
  • If you like, enter your Cost of Electricity
  • Click Calculate!

In one second, you will have a first year monthly calculation ofestimated AC energy produced by your system and its corresponding Energy Value.  How easy is that?  Do not be concerned if the site location isnot an exact address.  This is an estimate, and if your location isclose to the chosen city the difference is not material.

OK, now you have a very credible estimate of your first year’selectricity generation from your PV System.  Let’s convert this into a40 years projection.

The place to start is your module warranty.  Reduce your power production in accordance with the warranty specifications.

I will use Schott as my example.  The Schott warranty specifies 97% of rated power at the end of the first year, and for years 2 through 25 the power willdegrade no more than .7% per annum of the original rated output.  Actual field data has been considerably better.


Estimated power output of a high quality PV system over 40 years

Estimated power output of a high quality PV system over 40 years

Your PV system will not disappear after 25 years.  A high qualitysystem will keep on keeping on!  For my calculation, I apply the .7%power derate factor until year 40.  At that time, the system output isapproximately 70% of the original rated power.  Now I have a 40 yearprojection of power produced.


Year Annual power reduction
1 3%
2 – 25 .7%




Next, how do I convert this 40 year power projection to a monetary income stream?

Chet Boortz, CEO

Total Solar Direct

[The comments, positions, and opinions stated above are my ownand may or may not represent those of Total Solar Direct and itsaffiliate companies.]

Original Article on ses21usa

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Solyndra 30kW installation, Pasadena Independent School District, Texas

Lori shared those pictures of a Solyndra roof top installation in Houston:

SolyndraSolyndra (2)Solyndra (3)

Here’s what our friends over at Ignite Solar wrote about this installation:

The Pasadena Independent School District (PISD) SolarInitiative is the largest solar installation in Harris County.  Theproject is the result of a partnership between the Houston AdvancedResearch Center (HARC) and PISD and installed various solar technologies on two schools in PISD—Sam Rayburn High School and South Houston HighSchool.  The project represents one of the largest solar installationsin the Houston area and for a public school system in the State ofTexas.

The system installation consists of three separatetechnologies—crystalline panels, thin-film modules, and cylindricalmodules which are being used for the first time in the Houston area. Students will be able to monitor students to learn and work withscientists and engineers to track, monitor, and analyze data related tothe benefits of the diverse power technologies.
Panels were also installed on the south-facing awning above the secondstory windows at Sam Rayburn High School forming the biggest solarawning installation in Harris County.

We are proud to be a reliable partner for solar installers here inTexas! Thank you Lori for sharing this great solar success story and for sharing the pictures of the ribbon cutting!


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Texas Cracks the Top Ten in PV Installations

The SEIA and GTM have released their annual report, U.S. Solar Insight 2010TM Year in Review, and it’s official, Texas finally is ranked among the top ten states inannual PV installations at 23MW or a 2.6% U.S. market share.  This is afive times jump from 4.5MW in 2009.  About 70% of the Texas PV total isutility-scale.

Thank you San Antonio and Austin (MOU’s) for local RPS’s and demand incentives and Oncore for a one time rebate program and TARP and ARRA (SECO in Texas) for opening PV markets with stimulus funding.  2010 . . . it was a good year in Texas.

OK you Texas bashers; I can hear your snicker: 2.6% market share … wow.  Well, what makes this a remarkable achievement for Texas is that thereis virtually no help at the state policy level, the Texas environmentalcommission (TCEQ) is suing the EPA to dumb down air quality, the state’s two largest markets (Houston & Dallas/Fort Worth) are essentiallynon players with deregulated IOU’s, net metering regulations arecontrived to be ineffective, HOA issues, interconnections and more. This is an oil and gas and lignite coal state thank you.

Even so, consider this:

  • Texas is ranked 2 in state population
  • Texas is ranks 2 in state GDP
  • Texas produces an consumes more electricity than any other state
  • Texas electricity rates and utility bills are among the highest in the nation
  • Texas leads the nation in wind powered generation
  • Texas has enormous solar power potential

So with its 2.6% market share in hand, what’s next for Texas?  Basedon the current utility-scale PV project pipeline in Central Texas, Ipredict Texas will rank 5 or 6 by 2012; and based on the attributeslisted above . . . Texas will rank 1 or 2 by 2016.

How does Texas advance from number 10 to number 1 in PV installations . . .  one house, one business, one commercial building, one industrial facility, and one municipal building at a time! The momentum comes from users, the economic, social, and health beneficiaries of PV generation, it will not come from the state capitol or electric utilities.

Texas has a ferocious mindset of independence, and this coincidesperfectly with distributive PV generation.  The industry lobbyists(policy makers) in Austin may not be enthralled by PV, but they cannotprevent it . . . it’s your home or business; it’s your electricity bill; it’s your choice; and it’s your distributive generation PV system . . . it’s a ground swell movement.

In Texas, distributive PV generation provides an attractive economic return today.  It’s scalable and affordable, and it only will get better as the costof conventional electricity increases year after year after year.

It’s time.  Go Solar.  Go Texas . . . the Lone Star State!

Chet Boortz, CEO


Original Article on SES 21

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Solar panels shine at a Texas Home Show

From the ‘oil patches of East Texas to large urban centers, the PVsolar electricity markets are taking hold in Texas.  The ‘energy state’is all about energy and that includes solar electricity.

In Texas, we have oil, natural gas, and lignite coal . . . but the‘Lone Star’ state also has an abundance of good LIGHT.  That’s all thatis needed for clean, sustainable solar electricity.  PV . . . It’staking hold in Texas.

Installers all over Texas are part of this ‘movement’ and we’re happy if we can support them. So thank you Phil and Melissa for sharing thispicture of Schott Poly 230W and Bosch Mono 230W shining at a local Texas Home Show.


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Calculating the Internal Rate of Return (IRR) for your PV System

What is this?  OK, you are considering a serious capital investmentin your home or business; so you should consider a serious investmentmetric to qualify your investment!

The present value rate of return, aka internal rate ofreturn (IRR) is the interest rate at which the net present value ofcosts equals the net present value of benefits.  The IRR metricconsiders the time value of money – that is, the concept that $100 today is worth more to an investor than $100 20 years from now.  This is howsophisticated investors consider the desirability of a capitalinvestments.

An IRR of 0% means that the time value of costs and benefits over the investment horizon are equal or breakeven.  If the IRR is less thanzero, you have lost money.  If the IRR is greater than zero, you havereceived a compounded rate of return on your investment over theinvestment horizon at that interest rate.

Yikes!  How do I do this?  Well, it only takes minutes with a spreadsheet; longer with a financial calculator, or if you must, Google IRR for the formula and take a day of vacation.  Let’s assume the spreadsheet!

Remember, a PV system is a long-term investment, so we are going toreduce all costs and benefits to a single row of annual cash flows thatsum costs and benefits.  In previous writings, we have discussed how to estimate the electricity generated from your PV system and how to convert these kWh’s to a 40 year monetary value stream. 

We know that for a PV system, the capital costs are incurred in yearone.  Maintenance and operating expenses are nominal.  You effectivelyare purchasing 40 years of electricity with an upfront investment. 

There is one exception.  Your PV system includes a component called an inverter.  The inverter is the electronic component that converts the DC current produced by the modules to AC current connected to your electricity panel on the load side ofyour meter.  Most inverters have a warranted life of 15 years.  So, when calculating the costs and benefits, include the cost of a replacementinverter in years 15 and 30.

Create your spreadsheet with a 40 year annual cash flow summingbenefits and costs.  Your capital investment is in the first year, sothat year will have a negative cash flow.  Now, simply select a rate ofreturn function to apply to the data (for Excel, it is IRR), and in less than a second your IRR calculation is complete.

Once the IRR is determined, you can perform sensitivity analysis onyour result by making changes to your system costs and benefits andseeing how those changes impact the IRR.

Congratulations!  It’s your home or business; it’s your PV systeminvestment; and it’s your analysis.  Don’t rely on a canned solution. You know best.

The three most important variables are:

  1. How much electricity will your PV System produce?  (See PV Watts)
  2. How do you value that electricity?
  3. What does your PV system costs? 

Remember; do not sacrifice long-term performance for lesser upfront costs.  Quality counts!  It’s a long-term investment, so strive to maximize your price/performance ratio.

 Chet Boortz, CEO


Original Article on SES 21 USA

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Is PV Payback the Wrong Investment Metric?

In the conversational world of PV economics . . . the issue always is the same.  It’s a conditioned response.   PV is a great technology, but it costs too much, and the payback is way too long!

What?  Whose idea is this, and why has it stuck?  Payback is simply the wrong economic measure for evaluating a PV system.

Payback = cost of project / annual cash inflows

Two things we know about PV:

  1. The total cost of the system is incurred upfront; operating costs are nominal.
  2. The economic return (electricity generated) is measured over a very long period of time (25 to 40 years).

There are two major problems with using payback as the all-encompassing measure of economic success:

  1. It is simply a measure of time for the return of initial capitalinvestment.  It ignores costs and benefits after the payback period.  It is not a measure of system profitability.
  2. It does not pay attention to the time value of money.

Payback is a risk-weighted relic of oil and gas exploration economic analysis.  This oil well will payback in six months!  OK, that’s fun to think about, but what if it is a dry hole?  A PVsystem is never a dry hole.  Payback is not a measure of investmentreturn.  It is simply a time period. 

So when asked the question: what is the return on your PVinvestment?  The answer is a discounted (time valued) rate of return of___% over 25 years.  This metric respects initial and ongoing cashinvestments, operating expenses, income,  residual value, taximplications, and the value of money over a finite period of time.  This is the measure of economic value.

Quality counts.  A user may choose an inexpensive,low quality PV system and save 20% on initial system costs and therebyreduce the payback from 10 years to 7 years.  But, a PV system shouldlast 25 to 40 years.  If the system has a short payback but produceselectricity at a lower rate after 10 or 20 years, the investment returnwill be low.  In this sense, a short payback is a false economy.

Also, when you invest in a PV system (home or business), you become a small-scale independent power producer (IPP).  It’s as simple as that.  As such, the amount of power you produce over thirty years is mostimportant, not the payback.

When you make a capital investment in a PV system that lowers youroperating costs of your home or business, you immediately increase thevalue of your home or business.  How could it be different?  If youinclude this incremental value (15 to 20 times the annual value of theelectricity produced) in your payout calculation, the payback willinvariably be less than 5 years. 

So, payback is not the perfect measure, but if someone insists onasking, feel comfortable saying less than five years and that assumes no increase in utility rates for thirty years. 

Is PV economic?  Yes it is – from every angle.  Just do it!

Chet Boortz, CEO



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