Today it's my pleasure to introduce Miroslav ago that time he was a man and he asked to go over a diversity of the former Yugoslavia. You know after the one here is Ph D. from Virginia falling technically into the soup and enjoying the faculty of Shortly after nine pm He's an expert in power systems distributed energy generation transmission network analysis. He's a member of you suck which for those who don't know is the University Center for Excellence in formal tax one of the two in the country here to work back. He had published a number of papers a number of distinctions. One thing that I think is interesting is his work that went into the mobile tech array that is on the roof of the C.R.C. So for those who are unfamiliar with that there is a three hundred forty kilowatt or read on that that building harvested from the ground occasionally to get what you need to work but in general pharmacy at the time it was built for the Olympics in ninety six it was the biggest in the world biggest roof mounted in the world that distinction lasted about three months that's pretty much actually given a life that was not what I actually wanted and looked a little bit where we are today. Relative to forty years ago with regard to P.V. installations just that however everyone a little bit the largest group mapping system today is eleven point eight megawatts. OK And that's how the G.M. facility being the largest ground mounted system is sixteen or was about five times larger also expect the share or coal fired power plant just north of missing Georgia is three point four Google fifty six times larger than the largest around all day for all the support that we call work but we have a program to go without for further ado die. Thank you thank you. I appreciate the opportunity to talk to you all especially competing with this good weather and the holiday. It's a pleasure to be here and I will try to use the your time productively topic of my presentation today is about solar but I will start with the basics and then continue the issue of great integration is my my main concern. Well first to address the very important issue whether solar energy is truly renewable it really isn't really and when we think of it. This graph represents the so-called main sequence of stars in our known universe were the color temperature luminosity an absolute magnitude are shown on the vertical horizontal axis and our local star is somewhere in the middle of the main sequence generating energy mostly based on fusion of protons and helium and that process is and visions to last about ten billion years and we have been slightly less than halfway through it so we really have five more billion years then we have to find another solution for and there are probably. The interesting thing also is that the mass of the star with respect to mass of the sun gives us an estimate of how other stars are fairing lifetime wise and sun having a relatively small mass is is doing well in that respect the biggest ones are barely lasting top one hundred thousand years or couple million years. So we're doing well and that energy that is reaching the atmosphere of our planet roughly has a flux of one point thirty five. Q one for me to square and there are many mechanisms that take away from that the ozone layer absorbs about two percent upper and lower that's the way as air molecules all of it takes someone it's only about. Seventy percent of the direct light comes through the surface of Earth and then some of the energy comes as a scattered diffused light which is the reason why we see the sky is blue and not black and that overall energy is giving us about one kilowatt per metre square of straight orthogonal sun ray hitting the ground that of course becomes very different story when we look at the overcast winter day because there's much less of it. So there is just a cast of solar that has to be taken into account. There are other mechanisms of solar influence on the planet that needs to be taken into account the one point thirty five kilowatt or one kilowatt at the surface of it becomes true with about three hundred forty watts per meter square when we have reached that over time. And different mechanisms of absorption and reflection of that energy are shown here this by the way is one of the illustrations from the last issue of The Economist but it is sourced in the National Center for Atmospheric Research we see that portion of the energy is reflected by atmosphere part of the reflected and part of it absorbed by the surface but there is also part of it that circulates between the greenhouse gas layer and surface area. Some of which is operates. That's the reason why we have the kind of a climate that we have and the trends that are hotly disputed but undoubtedly changing. Nowadays. When they're just processes that are linked to sunlight we all are very existence to one of them is part of synthesis. Which is using sunlight in the plans to transform carbon dioxide water and sunlight into essentially sugar and oxygen sugar being a fuel of life. So that's one way of looking at that the other one. Of course is the solar photovoltaic cell which does similar thing but creates energy pure energy not using sugar as a vehicle for it and we will. We talking about that in the rest of my presentation. The availability of sun light and energy is shown here. I mentioned three hundred fifty watts per meter square as as the overall average how it is spread across the globe is shown here. And of course that means that it is not equally useful to put photovoltaic system everywhere on the planet. So we have to think a little bit about that when we when we speak in our more local terms in the United States we quite clearly see that there are some regions that are extremely well suitable for installation of large solar arrays. But we are very blessed that majority of our country is very well positioned to benefit from solar energy and and it is not just New Mexico and Arizona we're talking about we can benefit in Georgia. We can go as far north as Wisconsin and still have a usable output Now energy system. This is something from eighteen eighty two. It's as Edison Electric Light Do not attempt to light the room with a match simply turn the key on the wall. Don't forget that's less than century and a half ago. We've got a long way but distributed power the issue of resources and generation has changed a lot in the last century in the thirty's the cost was very large of new generation facilities real power plants the cost was gradually going down from the thirty's to seventy's and eighty's and was very low in relative terms it is not really important for us to look into the absolute terms but in late eighty's the typical large part plants were of the order of government or more. I was undergraduate student doing my internship in A.B.B. which was then called Brown Bavarian company in Switzerland and. There generators were fourteen hundred megawatts each at that time. That however has changed in the last thirty years we've seen a very much shift toward smaller capacities towards even cheaper energy but in the scale that allows installation integration into a grid at the distribution level something that has not happened before and that requires rethinking the whole concept of how systems operate here is what is happening in the large thorough fairs at the transmission level in the largest systems. We are now seeing thousands of megawatts being channeled across the country across the continents and that requires a lot more attention than utilities used to provide at the time when when the big first mission winds were just the backbone of reliability. So the systems have experienced over the past twenty or thirty years a lot of blackouts a lot of unforeseen contingencies that have created. Problems. It is now about thirty billion dollars a year energy business. It creates consequences when blackouts occur there are measured in billions of dollars so very careful introduction of measurement based information systems in an entire information infrastructure is being layered upon power networks to ensure that the decision processes are unable from the very short timescale of milliseconds to the longest time scales of months and years in planning for networks to operate at the levels of reliability and other requirements that are expected of such systems to happen. So we have all heard the notion of smart grids everybody is talking about them. Everybody is pretending to be an expert for smart grids. But what is really a phenomenon we have not worked on done great Still few years ago. So what what is being associated with the word smart grid is really a network that is unable or the. Functionality which is capable of dealing with certain requirements that are more and more important for the utilities and customers as well and being critical infrastructures for for many others. The transmission networks are generally used as thorough fairs to move large amounts of power over very large distances at high voltage level to keep the losses. Reasonably low local networks are distributing that power to customers usually using unidirectional flows and that paradigm is being increasingly challenge by these installations of smaller scale. Generation in the networks. However the functions that a smart grid is supposed to possess which networks haven't possessed in the past is the ability to do the self healing operation when something goes wrong the network has the ability to diagnose that to transfer their information you may or may not be aware that when there is a problem in an electric utility it is not a single alarm it's generated sometimes it's hundreds of them at the same time and the operator in the control center is facing reading one hundred alarms not having a clue what's happening there are special mechanisms that are sifting through that avalanche of information trying to identify what's going wrong and what is the best course of action. How quickly to cope with it. Well embedding that self healing ability into the network takes a lot of engineering experience and a lot of high technology and information systems and communication system is an extremely high synchronization time tagging to transfer all that information to a single center. Another aspect is demand side management. Customers are to be aware that energy doesn't cost the same amount if it is produced now or twelve hours from now and that cost is usually absorbed by the utility already. Ridged out. It doesn't have to be that way and the efficiency of operating the system may increase if that is partly made public and and if the customer is offered the opportunity to participate in that process in Europe it's been in existence for decades as a as a kid I remember that my parents used to turn on the water heater at night because the tariff was lower becomes very different when when you have to think whether or not to use electricity and how much you pay for it. We are blessed not to pay much too to think about it but it may change in the future and and it is likely to change phenomenon of resilience has been a lot debated recently resilience is not the same as reliability. If the system is challenged by an attack if it's challenged by a hurricane. If it's challenged by any process that creates not one but a number of contingencies in and degrades the system functionality resilience is the ability to channel the operation of the system so that the fractional part of the system which is in operation does its job with the least disruption. Reliability is another thing which is the system continues operating with the smallest amount of outages both time wise duration wise and in other ways. And of course promotion of electricity markets for hopefully lowering the prices and making competitive resources making resources compete for for presence on the market is another goal as well as running more efficiently from generation through transmission and distribution all the way to the customers and the things that I have labeled read here not to irritate you. But to emphasize the importance of it for photovoltaics that's to accommodate all generation and storage options including renewables. And accommodate higher penetration of intermittent generation sources wind and photovoltaics rip. Ideal examples of how. In addition to that we have to think about our infrastructures which are very tightly connected with energy we have water which is just as important if not more important in some ways and it depends on energy both by providing production through hydro plants and by requiring energy for treatment and transport. Similarly we have different ways of using land transportation and we have other infrastructures that are interconnected with this like information infrastructure gas transport and infrastructure. Those are all interrelated critical infrastructures that depend on energy in ways that we have to account for when we are planning and when we are dealing this. Here's a vision that is worth looking into even though it doesn't belong to to our country but it is a country that has done a very good work in transforming their system South Korea their vision of smart grid as they see it towards twenty thirty consists of five phases Smart Energy Service which is multiple tariff pricing system that I mentioned consumers electricity trading system then introducing large scale renewables into the energy mix then introducing smart transportation that relies on electric energy more than before doing introducing the concept of smart consumer with widespread use of smart meters and information that unable consumers to do energy management and utilities to suggest energy management to them and then implementing smart power grid at every level including two to two the highest level of transmission networks. So those are the goals the take decades to implement and some of the benefits that are in vision by South Korea are an increase in exports of course because their industrial country that produces a lot of infrastructure that we choir's to be part of. These phases and then include the inclusion of of new renewal because we're renewable power plants lowering of imports of energy which is very important creating demand in domestic only fifty thousand new jobs annually on average and so forth and so forth. Greenhouse with action being on top of it all. There are obstacles to smart grids regulatory environments that do not promote utilities to increase operational efficiency concerns that customers have over privacy access to electricity concerns about abuse that Enron and California debacle has created and so forth and so forth. So there are it's not an easy path and smooth way to do. Having smart grids there are pros and cons and there are people strongly in favor and strongly opposed there is another term that you should be aware of because it's called super grid. This is a concept that's been developed both for America and Europe and North Africa this is a concept of extending the large scale network continentally so as to include as many renewable resources into energy mix and creating what would become a very reliable very inexpensive very renewable and green network and this is a very I would say superficial map of how such a system is and vision to be with solar solar thermal photovoltaic plants wind plants hydro biomass geothermal all included into the mix and supplementing in large scale conventional power plants. Here is what would be the requirement in the United States to enable that just considering mostly wind photovoltaics is still in relatively. Beginning stage of implementation and large scale implementation affordable takes is yet to happen. The red lines represent the new seven hundred sixty five kill of all. Transmission Network that is and vision to be part of that new network the little green symbols represent the ceilings which are needed when very heavy transfers of high voltage are he was there into ties and existing infrastructure as you see is relatively miniscule compared to the needs. Here are the wind resources in terms of their usability and we see that. The areas labeled blue are superbly accommodating for introduction of wind farms and we have them pretty much everywhere in the country especially in the coast and the north the regions are very conducive to that. So it's not everywhere where the where the customers are and the infrastructure is needed. Here's another bit of information to consider annual U.S. natural gas imports have been relatively flat eighty five and since then they have been steadily going up and that represents not only an expenditure in terms of monetary investment but also a dependency which is in terms of critical energy infrastructure quiet unnerving. When you think about. Generation of new capacity by source in the United States has changed then and taken that into account Believe it or not but the fraction of wind resources that have been installed since two thousand and four is becoming more and more part of the energy mix. I would not have believed this till I saw this graph myself but apparently since it's been generated by Deo. It is correct. So wind is seen as a contender. And the requirements and the costs that are expected of the transmission network that needs to be built just like I showed a few slides ago are. Including many many benefits reduction of carbon dioxide are among them property tax economic activities and other factors including cost reduction of electricity due to renewables more than offset the cost of building the new infrastructure that is necessary to enable this transition here is another piece of information about energy networks. This is the cost per kilowatt hour average nationally and going from the late ninety's till pretty much today and we see that since early two thousand we have had steady slow this seasonal variations are typical but the slope is very easy to discern from from these prices we also see that the growth in demand has been largely fuelling this increase and that is worrisome and has different ways of dealing with it. We have huge untapped capacity of efficiencies. That can be used to keep our lifestyles without. Without increasing the demand for a new generation to be installed and that gives us a little time to think about what to do. Which generation is used to increase this energy mix is also important. Typically for the bulk of power that needs to be used all the time we use hydro coal nuclear makes which is traditionally the least expensive and it's trading on the energy markets waiting on fifty dollars a megawatt hour. When we get into the average demand and higher demand we get into a combined cycle turbines and other generation facilities that are in the fifty two hundred dollars range but in rare cases where additional capacities are needed and this is an example from New England the gas turbines and similar generation for so it is can increase the price to four hundred dollars a megawatt hour. When on top of that week. The problem with congestion. And the problem with where the money people ation of resources in transmission and distribution level those prices can go it with thousands of dollars in California. Actually they have been recorded up to one thousand nine hundred ninety nine dollars. The only reason for it not to go into five digit range was the software limitation of four digits for selling them. Here's another example from Australia which represents they we demand and energy peaks coinciding very strongly with what you see as light blue curve that are spot prices of energy spot prices in an energy hungry market tend to create huge spikes when the demand goes up force very short periods of time utilities are trying to cope with it but these spikes are a reminder that if you don't plan ahead and don't provide for very solid reserves. You may end up in a situation that you pay for electricity in certain moments multiple times the average price. So photovoltaics grid parity is a keyword. That represents the notion of an economic adaptation or are suitability of the system to be used in an energy mix so that the P.V. produced energy over a long period of time a lifetime of use of such systems is produced equally or cheaper than commercially produced energy of course that's easiest to be done where you have plenty of energy and I have cheap and very efficient systems. So some of these pieces of information provided in the items I don't have to read to you. They are speculative we haven't reached the point yet even though some estimates are showing late two thousand and eleven is the point when such things may happen but grid parity depends on levelized cost of electricity which depends on the amount of investment maintenance and fuel expenditures that is. Way over a lifetime of use and energy produced by the system and using all of that we get the price that can be expressed in different terms but the best ways to do it in terms of dollars are cents per kilowatt hour and compared with conventional resources and in that respect. P.V. hasn't fared well over the last couple of years or several years but the benefits and changes that are happening are increasing the attractiveness of P.V. tremendously I have borrowed this light from my friend colleague. Who's center has been one of the main reasons why P. has become cheaper and more efficient in the last twenty years and that's his road map to going from the current cost of producing P.V. cells up about two dollars worth of installed capacity down to less then dollars through incremental improvements in the manufacturing process through economies of scale through different evolutionary aspects of manufacturing fabrication in large scale which Sunnyvale his company is doing as we speak when we want to look at the suitability of implementation geographically of course we can average the impact of solar by calculating what a given system would produce equivalent in terms of hours of capacity operation and this is the same graph that you have seen earlier just transformed into that scale these numbers which of course months we expect you to read. They're showing how at different times of the year on average during the year different locations are fair in that respect in terms of kilowatt hours per meter square per day so that is something we can use as a guideline on when and where to implement P.V. systems. Here's another way to look at that depending on the cost of photovoltaic systems and on the you. That they produce in different locations we end up paying different prices per kilowatt hour. So everything that would be in the cost range of point to do so let's say three and a half dollars per kilowatt of installed capacity or whatever installed capacity and would be in the higher yielding areas of climate wise would produce these prices that wouldn't exceed fifteen cents a kilowatt hour combinations that are way below the yellow here are showing prices of fifteen to thirty cents a kilowatt hour in the red ones course combinations of expensive systems in low yielding areas so you want you don't want to put to an overly expensive system in Anchorage. Here's what would happen in Atlanta. Depending on how long we can use the system. This is the time of the system to more Times itself to a useful life time of the system and the system cost and these curves are eyes of coast curves of in cents per kilowatt hour So in other words if we pay the system four dollars per watt of installed capacity and use it five years we can expect this price but if we use it. Twenty five years we can combine that with a much lower price the combinations of prices and the length of life installation can provide for much lower energy prices and that's one of the factors to consider. Yet another factor is the energy required meant that goes into production of solar photovoltaic. Here is the result of a Dutch study that has calculated on average and worst case scenarios and optimistic scenarios for expenditures in kilowatt hours per meter square of the final product in different steps of the process of producing photovoltaic cells and it clearly shows that substantial energy goes into it when that's transformed into the level of energy. Produced versus installed capacity and when we look at that from the standpoint of insulation which is essentially the location of the system then these straight lines correspond to the years that it takes for system to produce the energy that went through its own fabrication. So in other words we see that since ninety two when the studies or early eighty's when these studies have been done the times for system to produce energy that went into its publication was as high as ten or eleven years but is now approaching one and a half to about three and a half years which is considered typical breakeven time for system as far as American production. And Mission impact affordable tykes also result of a study that was done on assumed models of sixteen percent capacity with a lifetime of twenty five years with a relatively low annual insulation shows that in all aspects of emissions P.V. fares and that includes mostly fabrication since we know that P.V. doesn't do these interactions in normal operation that are at the level of about five percent of other energy supplies so in every aspect including all impacts P.V. outperformed conventional energy systems. P.V. arrays are combinations of cells which are built to produce very large scale capacity. Here is an example of a sixty four megawatt power plant in our Tasia region of Portugal in the south of Portugal. Those are becoming true power plants we have a sixty megawatt power plant in all media on our corner in Spain which is also an impressive facility and forty megawatt cadmium telluride planted Poland's in Germany which is also a very large facility. However the world demand for photovoltaics last year till last year has been driven. Largely by the increase of capacity in Spain which was part of European efforts to increase the renewables and that has collapsed with the economic crisis that started in the late two thousand and eight. This is the diagram that I have got from one of the financial estimates of the Deutsche Bank. Which shows a clear decrease in demand which has underperformed the expectations of a brick ation that has created problems for manufacturers of P.V. because the demand that wasn't dissipated and was largely driven by Southern European installations has not happened. That has driven prices down. But it has also face first. Manufacturers to get into a situation where they may have to solve different difficult financial problems because of this discrepancy which is unlikely to be resolved very quickly looking a little bit on the engineering side. P.V. modules are operating essentially by producing energy proportional to about fifteen percent of their insulation flex that reaches the surface of the electrical characteristics of the cells. Depending on the flux that hits the surface looks like inverse diode and the maximum power point that they are reaching is always at or close to the NE of these curves in order to extract or force the operation of P.V. systems in that maximum power extraction mode we need power electronics devices to interface photovoltaic system with the grid to transform the essentially D.C. nature of energy production into sixty hertz good quality and energy that can be transferred into the grid and P.V. inverters are essential device to accomplish that. However P.V. inverter is being powered turnings the US is with several parts that are relatively unreliable have. Proven over the years less reliable the modules themselves which in many cases are guaranteed by the manufacturers over twenty or even twenty five to thirty year periods. Inverters are expected to last about ten to fifteen years sometimes less than that mean times between failures often are as short as five to ten years we've been lucky with our system in the aquatic center which fifteen into fifteen year of its operation still is using his first its first inverter and we're hoping that will last but inverters very expensive and depending on the replacement interval and taking into account the inverter cost as percentage of the entire system we see that the overall cost of the system taking in very three placements into account can change the life cycle cost in dollars per watt from say a nine point seven to eight point twenty six just by moving the replacement in the role from five to fifteen years. So that's another angle to look at when we think about cost of P.V. It's not just how much it cost to put it in year one. It's how much it cost in year six year ten fifteen and also how to use the inverter is inverters are having characteristics and efficiencies which happen to have efficiencies that change so if the inverter is operating at the relatively low fractional capacity it efficiency drops drop sometimes into seventy to eighty percent range a lot of energy is being lost. So we have looked into possibilities of using multiple in order to string inverters that can be designed in such a way so that they operate at higher fractional capacities and and higher overall efficiencies. When all of that is installed in the system we have the phenomenon called distributed generation where we have large scale capacities of power plants in transmission network channeling large amounts of power but we may have few cells. Micro turbines and different other resources also installed sometimes in distribution changing the direction of the energy flows and transforming. What used to be distribution feeders with unidirectional energy flaws into lycra grades that can have considerable consumer side benefits but some disadvantages as well. For example since the feeders are designed to be operational in a unidirectional powerful Ahmad all of the protective relaying all of the devices that are unable in their operation need to be redesigned hand sometimes considerable cost so that needs to be taken into account but the benefits that you can see. In terms of loss reduction in terms of peak shaving in terms of increase of reliability support for and sort of functions in the networks are undeniable and consider what I will not expect you to read is this tiny print this is just an illustration of what the utility needs to go through when a proposal is made for installation of such a facility in a distribution network or even something as mission at work. This is the result of a project that we've done for Georgia Power several years ago were essentially were going through the process of saying whether a proposal for a given renewable or distributed generation installation is acceptable for infrastructure where it's supposed to be connected or not and we look into the total capacity into the fold contribution to our location of contact with the system whether the low voltage circuit exceeds eighty five percent of short for cup ability several other factors including. Transients the billet dealing with different types of Fords and so forth and based on that the system passes or fails studies need to be done and the conclusion is the lower the capacity. Of the system the easier it is for it to pass such a test but it is very carefully evaluated and utilities are facing the problem of retrofitting new installations in to a system an infrastructure which is already hugely expensive and have been operating effectively over a long period of time. Reliability of the feeder is that our enhanced with distributed generation can be improved but not today. If anything happens to distribution feeder that has affordable tike installation. Today there is supposed to shut down the solar or whatever distributed writer is connected to it at the moment when this connection from the main that work is made so that. Crews can go on and repaired whatever's wrong with the infrastructure and that's the requirement regulatory requirement. It is estimated and vision that new version of the standard light AAA standard fifteen forty seven dot for which deals with these contracts will enable island in operation and in anticipation of that we've done studies that have accounted for a possibility for increasing reliability of the feeders. When they have say distributed generation like photovoltaic systems how it's done well. Typical distribution feeder has laterals which lead to customers and the main blanks and distributed generator may be placed at the forum location. If there is a fort in the network which may be the result of lightning strike or an outage. The system usually shuts down at the breaker and then the recloser is can be used to isolate the smallest portion of the system downstream of which the fort is. But if we have a distributed generator and fault of course somewhere here poor example then the story closers can be used to isolate the four to a portion of the system this portion will continue to operate because it's unaffected. And this is to really generator. If it's capacity matches. Load can continue operating in the island and more. That's what we envision as a possibility. And here's an example of such a system that can be split into several islands and modes each driven by its own distributed generators and feeding its load when the main supply ceases to exist. Depending on the number of recloser. And the capacity of distributed generation we can increase the attractiveness of such solutions here the lower height of the bars represents higher reliability because we have designed object a function to go down when and when the optimum is being reached. So with larger capacity of distributed generators and larger amount of switching devices we can reach very reconfigurable system that can operate at very high levels of reliability. So I will offer a few conclusions before I give you a chance to ask questions. Systems federal tax systems are becoming a lot more attractive. Nowadays because of the combined improvements in cost of producing them of reliability of the balance of system especially inverters. Although many problems remain unresolved. Because of the concerted effort of many governments to subsidize and actively sponsor so Lucian's to the energy problems and and climate long term impact problems that are happening in other costs are being dealt with in a very effective way by transforming in the whole Lucian refashion the technologies of production both of photovoltaic systems and the balance of systems advances in technology in terms of system efficiency are being made in we're expecting to see the twenty percent efficient cells produce that one to two dollars per watt of installed capacity range very soon. Grid integration in terms of reliability and resilience is happening and we will see a lot more of that combination of operating with large amounts large capacities of wind and photovoltaic stock Casti consensually in with will create problems that are yet to be addressed and would require substantial amounts of spinning reserves to be available in utilities that are operating that way but the experience of the countries European countries for example which have substantial wind resources are showing that twenty percent or more of penetration of wind or so solar photovoltaic resources would not be a problem it would be very hard to deal. And of course location climate and many architectural constraints and safety issues are also to be taken into account when we look at the medium to longer term outlook for such systems. So the future is bright. I see no way for P.V. not to undertake a more important major role in the future energy mix is in both industrial countries and developing countries which is interesting. Just like mobile telephony P.V. is good for both. Because it's much simpler to create an infrastructure on the standalone system bad basis then to build an infrastructure where there is none. And it is equally attractive to consider large scale installations in the places were such installations can in an economic fashion produce energy as it is already being done in Spain as you have to have will undoubtedly happen in our country as well. We are working as we speak on on a proposal for the Department of Energy trying to make Georgia Tech and a hub energy hub for the southeast and for the Baltics will be have a part of that. So having said all of that I will stop my talk and give you a chance to. How can you questions. Thank you thank you all so you know for your power to be over there. So what. I hear is that political or when you look here Jack. I think you need to be on your own. So yes this time it's not just an author now but what about all of us that he talked about with regard to the integration that prevents penetration as well there are several aspects to it that the think Knology of photovoltaic systems has evolved a lot in the last twenty years Georgia and South Eastern utilities are to be credited for having been early support there's another opt as of that technology which was costly and in some cases also hurtful. There was a company that I will not name which contributed modules that Georgia power installed in their system as a test facility which had within a few years completely ceased to operate that was many many years ago but such experiences are certainly not conducive to building confidence on the other hand when you look at the level lies the cost the photovoltaics in large scale integration. It's still relatively large it really needs to be produced at the level of a about a dollar per watt at the module. Plus another dollar to two a watt for the balance of system to compete over the lifetime. Favorably Oracle competitively. Here is a great article that we have seen different different installations in the world we can look at photovoltaics As million roofs that Germans have been talking about retrofitted to existing homes each bringing a few kilowatts of capacity and in fear cumulative impact substantially lowering the problems associated with energy peaks and and introduction of new energy resources but we can also think about Spanish model of building large power plants and utility scale which is the cheapest way of doing it and making power plants out of it that would probably be closer to economic to grid parity. So depending on on the approach you you can see the different problems and different price levels costs associated with it. The problem with transformation of infrastructure is not simple to resolve. If it is a widespread implementation that's invasion. It would require also a very careful reconsideration of the structure of distribution networks of the way they operate on the energy management systems going down to distribution level which is presently not being done. So there is a lot of adjustments that to be made and of course when you look at it from the cost perspective utilities today are capable of providing all the energy that we need in the southeast at a cost that is very competitive but looking ten or twenty years down the road and accounting for possible increases of energy prices which are around out there going to happen. Situation may become different it would be too late to start think. You know about such a solution when it happens most photovoltaic facilities would have a relatively easy way of being integrating into the system because a large amount of them so far have been of relatively small capacity. It is it is considered that up to about ten megawatts of installed capacity. Their integration is simpler. We have published papers on that and logic from one utility to another may differ depending on the type of distribution networks that are in question you would have one way of thinking when you're dealing with highly densely populated urban distribution networks or rural networks when you have relatively few customers scattered over over a wider your graphic range but in general photovoltaic systems have have not presented a great challenge to being integrated into distribution networks at the capacity level of the scene today. Yeah yeah well you can think about conventional systems suffering from the same thing you kill it. It really doesn't know when will you flip the switch of your conditioner or or any other device so there is this random portion of consumption that utilities have to deal with on a daily basis and it's well you know very well understood and there is a lot of stuff. Mystical historical data about patterns of consumption and dependencies on weather on time of the. Day of the week seasonal and others and and when you learn about predictive abilities that such repetitive patterns of use have you can cope with it with with great degree of certainty in a statistical way. Well the same thing happens with solar photovoltaic you do have uncertainty associated with cloudiness with the general weather pattern but in terms of filtered out whether you have typical matter a logical year for most locations that tell you what to expect in terms of overall yield and to expect in terms of ever smaller time frames. So the question that should be dealt with is how geographically scattered should be the installations of relatively large portfolio of photovoltaic systems that would in some way even out. Those spikes and valleys in generation that would be caused by transition cloud in the US and in every other way their average capacity would be estimated just like the weather is forecasted now days. So the issue of spinning reserve that would cover up those instantaneous momentary changes in output would need to be dealt with not with conventional resources used for baseline generation because they have very slow in their ship it would need to be dealt with with more expensive resources which presently are gas turbines which you have seen in my presentation are among the most expensive. But technology is also changing in the direction of introducing a larger scale storage capability is for solar which would in some way dampen the impact of those spikes and when you have a third fall you are of different generation technology. All of which are intermittent like wind and solar combined together they would tend to even out the the star cast the nature of each over over a larger capacity point for us. That is they're reasonably scattered. So I'm giving you a very quiet at the events or to a very valid question. The studies that have been done in the countries that have so far embark upon large scale installations of mostly wind facilities because they are far more economically viable at the present time have shown that penetrations of up to twenty percent or more are completely viable to be dealt with and have larger penetrations can be and can be accepted with with sufficient precautionary measures being taken. If if you if you expect me to tell you some very fancy new technologies. I will disappoint you. They are still relatively far from being implemented that utility. If you tell it to scale you will not see flywheel or superconductive energy storage at utility scale any time soon but those facilities that are presently available and very viable both economically and technology wise are pumped hydro for example. And whenever it is available and possible. They can be used for that purpose. I actually have one pump pump type of plant in that near Rome in Georgia pumped hydro Yeah those are hydro plants that are pumping the water out when there is a surplus of production. Actually and using it as a resource as a hydro plant when when it's needed. That's a very viable large scale utility scale storage technology. There may be others in the future and I know a lot of work is going on a lot of that but none of it is coming close to the cost reliability and availability that upon time drives. When you consider which technology is the best to implement in a given system you have to consider them all if you have hydro resources in that same area that technology has been known for ages and easy to read and is much less costly than others so that would be one obvious opportunity if you are talking about wind wind is also relatively cheaply available or considering the investment into infrastructure needed. So at what point photovoltaics becomes interesting or you need to have inexpensive enough systems. You need to have access to to relatively high efficiency and location that is yielding a sufficient amount of energy all of those factors need to be met and when they are met. We talk about grid parity and good parity means different things in different countries and different combinations of generation portfolio and demand because if the demand is meeting or exceeding available generation the prices are. Going up and that makes a good case for supporting P.V. even though it makes no sense but in some places there whether that is actually happening. So depending on how you look at that you may conclude different things about what would be the best options for building a generation and that doesn't even begin to include considerations that are looking into the climate change and emissions and other things. If those were to be accounted for in the energy price today we would see very different prices being talked about than what I have shown in this presentation those those are the lines that are invasion to be needed to facilitate the transfer of large amount of wind generation that is by USFSA to be produced when there is a plentiful wind in the north west in the IOW why and with Western Region in Texas area and since the load. Centers are sometimes remote from there the capacity and top quality of the network that I have shown represents or isn't vision to be needed to to provide the thorough fare for for all that energy to be transported to the customers and to do it reliably redundantly and reliable. However that investment is huge is generally considered that it cost about a million dollars per mile to build transmission lines that is in takes a long time to build the transmission line for a variety of reasons. So to to get their head. Requires substantial investment and one of the graphs that I've shown are demonstrating what benefits potentially offset that considerable investment which is into the tens of billions of dollars needed to be made for such a system to affectively integrate into the national energy portfolio. Or at eighteen percent efficiency is a cell efficiency you have a six by six inch wafer produced in the factory which is eighteen percent efficient you pack those cells into modules that are about ten square feet or so and suddenly the efficiency is down to sixteen percent for a variety of reasons the differences between the cells in the life it's all characteristics the losses in the interconnect and so forth and so forth. So we're down to sixteen percent then we enter connected into a large system like some of those that I've shown and put the inverter there in isolation transformers and the efficiency is down to maybe twelve percent. So we are not at twenty. We are operating more like a ten to twelve percent efficiency. The downside is it is really just a small portion part of it is unavoidable because the spectrum of solar insolation is such that it cannot be completely and effectively exploited by the semiconductor nature of the most commercial use photovoltaic materials the other reasons exist. Also for that but we have plenty for resources and many locations are providing so much of insulation manual insulation that it is really a matter of producing a cost effective way to to to to get the benefits of it where it becomes. It is if you're trying to install such a system on the roof of your home you have so much roof. So more efficient system means more capacity but if you are putting that system out in the field whether you would be using quarter square mile or a square mile is much less important not an important. So efficiencies are however on their way up and the reason why it's important is because if they are driving costs down. The way first silicon wafers that are used in production or photovoltaic systems lose about fifty percent of the material just in the sawing of wafers which are one hundred eighty microns. Thick now days. So fifty percent of that silicon which is hugely expensive which twenty years ago was produced in the amount of two tonnes worldwide per year just for the semiconductor grade up we cations now days and we see the demand surge for such systems because wafers are large we need a lot of them and we know we need to do that effectively So if we pack more efficiency into that material we're extracting more energy out of less material less energy has been imported into into it's fabrication. And that's why it's important to get above twenty percent and to do it cost effectively. And up to twenty five percent efficient systems have been produced and have been in existence for decade or more but they take so much time and so much care to produce that it is completely irrational to even think about making a commercial case business case for such things to be done so move on the other hand is producing eighteen percent efficient cells in in a couple of hours and in a completely automated process that's very very effective and will become more effective than that and that's the path to go. I hope I didn't get too verbose in explaining. For photovoltaic. There is very little needed in in terms of that as far as window washing manufacturers of models are looking into the types of costs or materials. There are just three pellets in a way so that they take care of it by themselves. I don't think that any such activity is taking place now in any of the installations in an organized way the main reason for the cost of operation and maintenance of photovoltaic systems are down times that are caused by failures. Most of the failures are caused by power electronics that's associated with systems with our photovoltaic system on the aquatic center we have experienced a number of down times. First of which happened within a few weeks of installation in ninety six where we had a big lightning storm which took about a third of the system the fuses were born in one third of the two twenty eight hundred modules. We had to go and replace all of those modules within days before Olympics began but most of the failures afterwards were failures of the inverter which were either driven by the thermal mismanagement problems with the fan which ultimately was replaced with another design or failure of capacitors and the inverter which are not Torrijos we are reliable Some manufacturers have even proposed to do. Inverters that would have a higher grade reliability thereby introducing military spec capacitors and other parts so that they become. Truly maintenance free or to make them in such designs that you could you do use a replaceable capacitor just like you would replace bulbs in your home. So when the capacitor blows you just put the new one in continue operating the Lord but those are the main reasons for the for the cost of installation which is minimal such systems are capable of operating for extended periods of time and as long as you operate with with some amount of data acquisition and diagnostics that that hits the eyes of a living person so that the problems become recorded the system can operate on attended for for a very long time yet there are many technologies about many of them. I don't know much because I'm mostly interested in those aspects of P.V. technologies that are on the verge of being implemented in relatively large scale. So organic is is an attractive technology potentially but it's low efficiency at the present time and relatively high cost makes it not really an emerging technology it's something that may happen down the road ten twenty years down the road and there is a lot to be done some of which may never happen. It's hard for me to make predictions probably probably bring our people in who was one of the speakers in this forum would have been much better person to ask that. But on the other hand when we look at P.V. becoming part of the energy mix. We should look into technologies that are good. Right now Little become better within a few years and that in my opinion is among other things a modern point crystalline silicon which can provide relatively large capacities relatively low cost. So that's that's the current prevailing thinking ten twenty years down the road. We've been thinking the same about the more for silicone thin film that turned out to be an unreliable technology low efficiency and the cost was not attractive enough to offset all the disadvantages. But we have accumulated enough knowledge and experience to be fairly confident about the Bright Future of crystal and so if we're in the foreseeable future. Yes you are unlikely to see a utility embarking on producing a thousand megawatt plant when it can do the same with another technology of a fraction of the cost on the other hand however utilities may and will probably continue to experiment with it in expectation of the prices to go further down and large scale facilities becoming more attractive and possible that that I think is one driver the other one is you can you can foresee the future affordable taxes retrofitting it in small installations sell millions of homes or doing larger installations in larger capacities essentially producing the same thing. The cost undeniably favors the latter. So what can be done and what should probably be the way to start first is to look into facilities that can offer near load centers such opportunities for example large warehouses where the roofs are on exploited and used for other things that they can provide some shelter from heating while at the same time being used for energy production. So if you approach Walmart or or other facilities that have huge warehouses. Those would be perfect examples of where utility scale systems could be built in urban areas without disrupting the landscape too much and that would be my way of proposing to have that the inroads for P.V. begin future may be different but that I think is the starting point.