Objective

Our main objective is to analyze and compare the revenue a farm land provides a farmer in the United States if he sets up a Photovoltaic plant on it, rather than growing cotton/tobacco or Alcohol.

The Literature review will be divided into two stages:

• Agricultural data- In this section, all articles providing statistical information about Cotton, Tobacco & alcohol will be discussed and reviewed. The information we are interested in will be agricultural in nature: Yield ($/acre), Harvested acres, Value of the crop, Expenditures incurred etc.

This piece of information will help us plot various sensitivity graphs for these crops and compare them against PV graphs.

• Photovoltaic Farms- In this sections, all articles pertaining to Solar PV farms will be analyzed and useful information from it will be summarized. The information we are interested in should be have both Technical & Financial content.

Cotton Production Statistical Data in Georgia, USA

Cotton Production Statistics in Georgia, USA.^[1] Abstract : The link provides extensive details about the cotton production in the state of Georgia, USA published by the Georgia Cotton Commission. The data which is of much interest to us in this project would be:

• Yield (average pounds per acre)
• Crop Value (both lint & seed).
• Total amount of acres planted
• Total amount of acres harvested

These details would be very useful to us when we compare the remuneration provided by PV farms vs the efficiency cotton crop produces. We can choose a specific farm in of the counties mentioned on the link. We will calculate the amount of acres used by PV farms and the income it provides VS the amount of acres used by the crop and the $/acre it provides.

Cotton Production Statistical Data in Missouri USA

Cotton Production Statistics in Missouri, USA^[2]
Abstract: The link provides an insight into the crop production & efficiency in the state of Missouri USA. This link can prove to be an excellent source as we can use the following data for our project:

• Harvested Acres
• Yield (pounds per acre)
• Average annual price over the last 5 years.

Tobacco Production Statistical Data in North Carolina, USA

Tobacco Production Statistical Data in North Carolina, USA^[3]
Abstract: We have chosen North Carolina because for the year 2013, it had the highest production of Tobacco. Tobacco has always been a very important contributor to North Carolina's economy. Once again the link provides abundant relevant data like :

• Yield (Pounds per harvested acres)
• Harvested Acres
• Value of Production (Dollars/Acre).

We can choose the data used for Burley Tobacco crops as these crops are used to make cigarettes. The link also provides us data like the number of farms allocated to the various counties in the state. This will help us use GIS over a particular farm very easily.

Alcohol Production Statistical Data in Michigan, USA

Alcohol Production Statistical Data in Michigan, USA^[4]
Abstract: The paper, published by the researchers of Michigan State University, gives a detailed description of the crop Barley in the state of Michigan, USA. Barley is primarily used in the production of Beer and is extensively grown in the Northern Part of North America. Though the paper goes into detail the way a Barley crop is planted, grown and harvested, we are primarily interested in the data provided about the

• Michigan Barley production ranging from 1914-2013 in Bushels/acre
• Economics: $ received per Bushel.
• Break up of the expenses incurred by the farmer per acre during the process of growing Barley.
• Average Yield for the year 2013

One very unique characteristic about the paper, which may prove to be very helpful for my topic is that the paper provides an in depth break up of the expenses incurred by the farmer per acre during the process of growing Barley. This data can prove useful when we compare it to the expenses incurred while installing PV systems.

Cotton Production in California

Cotton Production in California^[5]
Abstract: California, being a large producer of Pima Cotton, is an ideal area of research as it has the largest % of PV farms too. Hence it would be easier to base our research around this region. The data provided in this article which is relevant to us is:

• Production Area- with the help of various demographic & statistical figures, this section gives us information on the number of acres used for Harvesting purposes.
• Yield-The section provided data about the pounds of Lint Cotton per acre.

Fertilizer use per acre- Data about the type of fertilizers used per acre is useful to us as it would be an important factor while plotting the sensitivity graph of cotton for the next 25 years.

Georgia Tobacco Farms

Georgia Tobacco Farms^[6]
Abstract: This article provides agricultural information about the quantity of Tobacco produced in various counties of Georgia. Data which we can pull of this is:

• Harvested Acres
• Yield per Acre (in Pounds)
• Production (in Pounds)
• Revenue earned per 1000 acres

Barley in Colorado, USA

Barley in Colorado^[7]
Abstract: The state of Colorado is well known for its large production of Barley. Since it also has a large % of PV farms, it would be useful to pull out the following information from the article:

• Acres Harvested
• Yield per acre
• Production
• Value per unit
• Total Value
• Prices received by farmers

Agriculture Projections to 2016

Agriculture Projections to 2016^[8]
Abstract: The article, published by the United States Department of Agriculture, studies how agriculture statistics like farm income, food prices etc will change in the upcoming years. The article covers the crops we are interested in primarily, and will be immensely useful to us in the following ways:

• Information provided about Crop projections in the near future- The article describes how the growth in population, strengthening of US Dollars etc will cause an increase/decrease in the farm income for the farmers.
• Projection of Cotton- A section of the article describes how the use of mills for upland cotton will fall due to increase in imports.
• Projection of Tobacco- Declining cigarette consumption in the USA has this article predicting the decrease in the production of Tobacco in the near future.
• Prediction in the decrease in the amount of acres of plantation- A nice graph shows how the Acres of Plantation of Barley and upland cotton gradually decreases from 1980-2015. This can help us plot a graph to compare against growth in PV demand.
• Focus on upland cotton- A section of the paper concentrates on cotton, predicting how the domestic mill use and exports will increase/decrease by 2015. It also discusses increase in USA imports of apparels causing the decline in cotton mill use domestically. This would eventually earn the farmers less income.
• Focus on Barley & Tobacco- A section of the article also describes how the domestic use and exports of tobacco and barley will increase or decrease with the help of a graph.
• USA Barley, Tobacco & Cotton long term projections- Probably the most important section, this table discusses how the average yield, prices supply etc of all the mentioned crops will behave in the upcoming years. This data will be immensely useful when we do a sensitivity analysis.

Crop Production Data

Crop Production Data^[9]
Abstract: Although we have many literature on this topic, this article is particularly useful to us because:

• Cotton & Tobacco statistics in various states of USA- This article provides us all the statistical data (yield, harvest area etc) of cotton and tobacco in various states of USA. This gives us a wider range of survey.
• Better tabulated results- This article has a very clear tabulated results of all the statistical data we require. It covers barley, cotton & tobacco and it has the most up-to-date data (2013-2014).

Economics of Tobacco

Economics of Tobacco^[10]
Abstract: This article discusses in brief the economics of Tobacco crop in USA. The information that will be useful to us is:

• Tobacco growing- This section discusses how the production & demand for tobacco in USA is on the decline as we look backwards from 1973 to 2003. This can help us predict the decline in the upcoming years. The section discusses how cigarettes are imported these days.

There are very informative graphs in this section that show how the production of tobacco is decreasing in USA as more number of cigarettes are being imported. These graphs will be useful to us when we plot graphs in our research.

• State Data and Trends- A section of the literature also discusses on the state wise production, manufacturing and utilization of Tobacco. States like North Carolina, Georgia etc are being discussed. Since these states are already of interest to us, this section can provide us vital information. Referring the graphs, productive information about Tobacco manufacturing and farming have increased/decreased over the past few years.

Cotton production in Arizona

Cotton in Arizona^[11]
Abstract: Cotton is a major crop grown in Arizona. The Pima variety of cotton is most famous in Arizona. Since Arizona also receives a high Irradiation value, and we have already discussed a PV farm in Tucson, Arizona; it will therefore be useful to discuss the growth of cotton in Arizona. The data which we can pull of the article is:

• Area Harvested in Acres in 2012-2013
• Yield in Pounds per acre
• Production in Bales
• Specific data about Pima Cotton: Area Harvested, yield & production

Sensitivity analysis of energy inputs for barley production in Hamedan Province of Iran

Sensitivity analysis of energy inputs for barley production in Hamedan Province of Iran^[12]
Abstract: The main objective of this article was to analyse what components of Barley farming consume maximum energy. This approach will be beneficial to us as it will help us evaluate what are the major factors that cause expenses in Barley Farming due to which farmers can actually consider PV farming. The main points in this article which we can use is:

• What are the different types of fertilisers used?- This article enlists the different types of fertilisers, biocides etc that are used for Barley farming. Instead of looking elsewhere, this article can provide some reference when evaluating the expenses incurred by the farmer while using these items.
• Total Energy consumed - The section has a table that discusses the total amount of energy consumed by various components of Barley farming, like , energy consumed by Machines, fuel, fertilisers etc. This will help us get a good idea about the expenses incurred by the farmer.
• Results from Sensitivity Analysis- After performing the sensitivity analysis, various conclusions were made which will be of great importance to us. The results discuss how increase in labor or biocides increase/decrease the yield etc. This data will be of good reference to us.

Though the data is relevant to the country of Iran, it does give us a good idea on how to go about doing a sensitivity and expense analysis in USA. Hence this article will be of good significance to us.

Barley in Wyoming

Barley in Wyoming^[13]
Abstract: Wyoming is a major producer of Barley. As we are going to discuss PV farms in Wyoming, it will be useful to find out the statistics of Barley production in Wyoming. The information, as of 2011, that we can pull out is:

• Number of Acres where Barley was planted
• Harvested Acres of barley
• Yield per harvested acre
• Production in acres
• Expenses incurred by farmer
• Temperature Data

PV Setup in Georgia Power Headquarters, A Southern Company.

PV Setup in Georgia Power, a Southern Company^[14]
Abstract: The state of Georgia, USA is actively trying to harness the potential of Solar Energy. Since we have chosen one of the non-food crops (cotton) to be in Georgia, it would be ideal to collect information about various types of PV setups in Georgia. One such PV setup has been established by Georgia Power's Corporate Headquarters in the year 2009. Their setup basically consists of rooftop PV arrays with the objective of producing electricity for the building. Their project, funded by Southern Company, can provide relevant details for our project as one of their objectives is to provide cost & performance data to help their customers. Through their interactive website that provides real-time web data we are interested in the following information:

• Total capacity of the PV setup - The website describes the kW capacity expected from the setup. This information is useful for us as we can then infer how much kW of power can be produced with their kind of PV array setup.
• Solar Production - The company publishes the amount of Solar Power they produce on a daily basis. Although this feature is currently not yet active and is "coming soon" , this feature can provide valuable data.
• Weather - Probably one of the most valuable features the company provides, this feature gives us information about the amount of Irradiance (W/m^2), Module temperature, Ambient Temperature Wind Speed and Wind Direction. This information combined with the Solar Production data, can help us analyse the amount of Solar Energy produced under a certain set of conditions.
• Comparisons- Although this feature is currently under construction, the data obtained from this can help us analyse the Energy data produced on a daily basis and compare it against the other data too.

Limitations faced-

• Owing to the confidentiality of the project, it may prove difficult to obtain the exact technical specifications of the Arrays and the Inverters used. Obtaining other kinds of Technical Data may also prove to be difficult as the company may not be ready to divulge the information.

Solar Farm in Colorado

Multicriteria GIS modeling of wind and solar farms in Colorado^[15]
Abstract: The basic objective of this paper was to analyze the suitable land area to tap solar (and in this case wind also) potential in Colorado, USA. The paper publishes its results based on using various Geographic Information System (GIS) modelling techniques to find out which land cover was most suitable for a Solar Farm.
Since our project involves simulation & design of Solar PV farms using the information provided by GIS, this paper can provide an useful insight on how to model a efficient PV farm based on information obtained from the GIS.

The following information from this paper is useful for us in our project

• Methods to Obtain relevant data- The article describes what are the exact parameters required to design a solar farm. This is can prove to be helpful when designing & simulating our PV farm.
• Land cover characteristics for solar- This section of the article proves to be an excellent source of valuable information as it defines what type of Land Cover has the maximum solar potential. For example, the article describes that the Inter mountain basins landscape have maximum Solar Potential. Hence while designing our PV farm, in order to maximize efficiency, we can keep these factors in mind.
• Using GIS model to locate land masses with maximum Solar potential- A section of the article describes how to use the GIS model scores in identifying land masses which have a very high potential for tapping Solar Energy. We can refer to this method in our project.

Parallel DC-AC Conversion System Based on Separate Solar Farms with MPPT Control

Parallel DC-AC Conversion System Based on Separate Solar Farms with MPPT Control^[16]
Abstract: This article focuses primarily on the simulation part of a PV farm, which can provide us useful information on how to go about building and simulating a PV plant with the help of MATLAB SIMULINK.

The information from this article that is relevant to us is:

• Energy conversion Model- The paper describes the exact model employed by them to get the Current, Voltage and Power curves of each solar farm. This model, which primarily behaves like a distribution system too, can come in handy when we simulate our PV model.
• PV panel model- The article also describes the type of PV panel used and the o/p capacity it possesses. They also briefly discuss the characteristics of the panel, like voltage & current parameters etc.
• Inverter characteristics- MATLAB wave form outputs of the Inverter are also published to help analyze the AC output for the said given DC input. This can be useful in studying the efficiency of the system.
• Formulae for calculating Photovoltaic Cell Current & Voltage- The paper employs a simple formula to calculate Ipv which is basically the current at the o/p of a Photovoltaic cell. This formula can be employed by us in our research.
• MPPT algorithm- Through the results of the Simulation, it is explained how the Perturb & Observe MPPT Algorithm works.

Renewable energy potential on brownfield sites: A case study of Michigan

Renewable energy potential on brownfield sites: A case study of Michigan^[17]
Abstract: The highlight of the journal paper is to show the potential a Brownfield land has in being replaced as a potential land for Solar Farms. Since this paper is a case study of Michigan and we had chosen one of the non-food crops to be in Michigan, this paper can provide us certain interesting & relevant details like:

• Solar Potential map of Michigan- This map, prepared by the Michigan State University, shows the areas of great-low solar potential in Michigan. Hence, if we were to design a PV farm in Michigan replacing the non-food crop, this map can prove to be useful as it also displays the Irradiance value in W/m^2.
• Solar Power production- The journal paper describes how much Solar Energy o/p is produced using standardized PV arrays. The amount of Irradiance received in Michigan was obtained from the National Oceanic and Atmospheric Administration weather data.
• Tech Specs of PV array- "The PV module power ratings are for Standard Test Conditions (STC) of 1000 watts-per-square-meter solar irradiance and 25 °C PV module temperature. The default PV system size is 4 kW (kilowatt). This corresponds to a PV array area of approximately 35 square meters (377 square feet). As the standard array used by NREL requires a footprint of 0.15 acres to avoid shadow and other problems, the final potential estimated for solar is 1535 MW"

Statistical Modeling of Energy Production by Photovoltaic Farms

Statistical Modeling of Energy Production by Photovoltaic Farms^[18]
Abstract: The paper basically deals with a statistical approach to model a PV farm in such a way that we are capable of predicting the energy output of each PV cell. The area of interest to us in this journal article is the way the paper uses an unique approach that relates weather conditions over an area of interest with the electricity production of the PV cells. Though the case study was based in Czech Republic, we can incorporate their methods while modelling our PV system.

AN INVESTIGATION TO USE TAILING PONDS AS SOLAR PHOTOVOLTAIC FARMS

AN INVESTIGATION TO USE TAILING PONDS AS SOLAR PHOTOVOLTAIC FARMS^[19]
Abstract: Although the main feature of the paper is to discuss how a Tailing Impoundments can be used as PV farms, which may not be of any interest to us, the paper does provide some very useful information to us like:

• Configuration of the Solar Panels- The article provides the various types of semi-conductor materials that goes into making a PV cell along with the orientation & different types of PV arrays that maybe used. The configuration, as set up in Tucson Arizona, shows how the tilt of the arrays should be to avoid shading and to maximize Solar efficiency. It also discusses the capacity o/p that the setup can produce.
• Expenditure of PV farms- This section provides us very valuable information: it discusses the expenses incurred by the aforementioned PV configuration. This information will help us draw a nice comparison sheet against the expenses incurred by a Non-food crop.
• PV hardware description- Existing in this article is a very succinct table that describes the different types of PV modules along with the number of modules, their capacity, type of Inverter used and the O/P expected.

Solar Power Analysis & Design Specifications in Houston, USA.

Solar Power Analysis & Design Specifications in Houston, USA^[20]
Abstract: The basic objective of this published document was to design & implement a Solar Farm on a landfill in the city of Houston, Texas. The information that would be relevant to us in our research is:

• Type of Solar panels used- The article describes what type of solar panel they chose depending upon the electricity o/p that they required.
• Configuration- The tilt of the solar arrays along with their dimensions is also mentioned. Spacing between the modules is also discussed to avoid the effect of Shading.
• PV system design- Based on the expenses as well as keeping in mind the efficiency required, a detailed analysis and description of the exact design of the PV system is discussed. Issues like types of PV panels, tilt, tracking and wind loading are discussed in depth and necessary solutions have been published. This is very useful when we design and simulate our PV farm.
• Specifications of the PV system equipments
• Cost Estimate for the PV farm- Economic Analysis of the designed PV farm is done and the results are tabulated. This will be relevant to us when we tabulate such results against the data of non-food crops.

The Long Island Solar Farm

The Long Island Solar Farm^[21]
Abstract: This journal article discusses the largest Solar Power Plant in Eastern United States (New York). Our main area of interest lies in these following topics of the article:

• Technical Design- The paper describes in depth the capacity of the solar plant and accordingly the types of Solar modules used, their method of installation, Number of Modules & Inverters and module tilt and many other relevant details.

SunEdison Photovoltaic Solar Power Farm Davidson County, North Carolina

SunEdison Photovoltaic Solar Power Farm^[22]
Abstract: Since we have reviewed an article discussing the growth of Tobacco crop in the state of North Carolina, it would be hence advantageous to study any existing solar farms in North Carolina. Though this article is very brief, it does provide the following information for us which can prove to be useful:

• Output capacity- The PV setup is expected to deliver 16.1 MW (AC) to its customers.

Planning and Zoning for Solar in North Carolina

Planning and Zoning for Solar in North Carolina^[23]
Abstract: The basic purpose of this article is to plan and evaluate the idea of establishing Solar Farms in the state of North Carolina. This article can come in handy to us when we plan to replace a tobacco farm with a PV farm in North Carolina. The information that can be useful to us is:

• Description of a PV plant- The article describes very aptly a summarized version of all the equipments required for a PV plant. It describes the different kinds of PV arrays, panels and cells required and which one is more efficient than the other. It also takes into account the mounting, tracking concepts too.
• Standards for solar- The paper also discusses the main factors that have to be kept in mind while establishing a PV setup, like: Height, Glare, Size etc. These factors will play an important role when we design our PV farm.
• Zoning & Planning of Solar- The article discusses in brief as well as provides excellent weblinks which discuss how to decide which zones in North Carolina are best for Solar Farms and how to go about establishing these farms.