This is not only due to the fact that you need to determine the energy demand of your household, but you also need to pick the best mounting systems, suitable photovoltaic panels, inverters, batteries and type of the system… The value of voltage is the same as the nominal voltage of batteries. Inverter sizing. The site editor may also be contacted with questions or comments about this Open Educational Resource. Types of Solar Panels and Which Solar Panel Type is Best? It should have a minimum voltage drop and have minimum resistive losses. To know the needed total WPeak of a solar panel capacity, we use PFG factor i.e. For this reason, many property owners will hire an engi… Energy demand Watt-hour = Power rating in Watt × Duration of operation in hours. This way, You will receive the new articles notifications in your inbox. Required fields are marked *, All about Electrical & Electronics Engineering & Technology. The cable must behave minimum voltage drop typically less than 2% as there is an issue of voltage drop in low voltage system. But as the individual battery is of 12 V, 100 Ah only and the system voltage requirement is of 24 V we need to connect two batteries in series to get the system voltage of 24 V as shown in figure 2 below: So, in total there will be four batteries of 12 V, 100 Ah. Thus, the unit can be written as watt × hour or simply Wh. of batteries required = Required charge capacity / (100 × 0.7), No. Architecture of the large-scale PV systems. Design aspects of large solar photovoltaic systems (non-pumping applications) 149 9.1 Load calculations 151 9.2 Sizing of Module /Array 156 9.3 Sizing of Storage Battery 159 9.4 Sizing of Charge … Can this article be downloaded in word or PDF format? Thus, 2 batteries of 12 V, 100 Ah are required. This course supplies learners with the insights necessary for properly planning, and therefore successfully installing, a photovoltaic (PV) system per design specifications. Initially, the PV plant design is developed at the stage of feasibility assessment which includes estimation of solar resource and expected yield. Most of our energy need is usually satisfied by non-renewable sources of energy such as coal, crude oil, natural gas, etc. Today our modern world needs energy for various day to day applications such as industrial manufacturing, heating, transport, agricultural, lightning applications, etc. Therefore, two 12 V, 100 Ah batteries in parallel to meet the above charge capacity. Now, a 50A charge controller is needed for the 12V DC system configuration. 86-98. Now let’s find the number of solar panels, rating and sizing of charge controller, inverter and batteries etc. As the cables would be placed in the outdoor environment it should be water-resistant and ultraviolet. Site assessment, surveying & solar energy resource assessment: Since the output generated by the PV system varies significantly depending on the time and geographical location it becomes of utmost importance to have an appropriate selection of the site for the standalone PV installation. For choosing the proper inverter both the input and output voltage and current rating should be specified. Suppose the PV module specification are as follow. While assessing the solar energy the data can be measured in two ways as follows: Peak sun hours are most commonly used as they simplify the calculations. The required rating of solar charge controller is = (4 panels x 10 A) x 1.25 = 50 A. whereas the oversizing is not economically affordable. If the available battery capacity is 175Ah, 12 V, we may use 3 number of batteries. Development of large solar PV plants has been underway in a number of countries, especially where the government-backed incentives and legislation were in place to support renewables. Let us consider in our case the daily energy consumption by the load is 2700 Wh. See solar designs examples. How to Design and Install a Solar PV System - Solved Example But the utilization of such resources has caused a heavy impact on our environment. Sunlight allows photovoltaic (PV) modules (also called solar panels) to produce electricity and perform useful work, such as running electrical loads or putting energy back into the utility grid.To get started in the burgeoning business world of photovoltaic design and installation, you need to know a few basics, such as the main components in a PV system design… of batteries required = 125 Ah / (100 × 0.7) = 1.78 (round off 2 batteries). The design of a utility scale PV plant is a complex endeavor. The average and maximum size of the utility solar plants (typically 5 MW to 500 MW) increases as well. The book is a comprehensive resource and reference guide that covers the entire perspective of large scale solar power system design, deployment and economics. As there is only AC loads in our system for specific time (i.e. You can find the exact number of solar panels by dividing the W, Sunlight not striking the solar panel straight on (5%), Not receiving energy at the maximum power point (excluded in case of MPPT charge controller). 2015 IEEE Power & Energy Society General Meeting. Why? Suppose, in our case the load is 3000 Wh/per day. One of the most common way to determine the sizing of the PV array is to use the lowest mean daily insolation (Solar irradiance) in peak sun hours as follows; The total size of PV array (W) = (Energy demand per day of a load (Wh) / TPH) × 1.25. It is readily available in an abundant form and has the potential to meet our entire planet’s energy requirement. Required Number of batteries = Required capacity of batteries in Ampere-hour / Available battery Ah rating. Because power is measured in an instant, it can vary widely over time and from minute to minute. Note: The value of PFG (Panel Generation Factor) is varying (due to climate and temperature changes) in different regions e.g, PFG in USA = 3.22, EU = 293, Thailand = 3.43 etc. Peak sun hours are most commonly used as they simplify the calculations. Photovoltaic projects range from small-scale projects for lighting and pumping to large-scale projects for whole buildings and even utility-scale photovoltaic "farms." Up tp 93% Off - Launching Official Electrical Technology Store - Shop Now! Series, Parallel and Series-Parallel Connection of Batteries. is based on how much power will be passing through a specific component of the system. Thank you. The standalone PV system is an excellent way to utilize the readily available eco-friendly energy of the sun. Therefore, two 12 V, 100 Ah batteries in parallel to meet the above charge capacity. This will increase the number of batteries in the series. Now for our case let us consider the system voltage of 24 V. While sizing the battery some parameters are needed to be considered as follows: Let us consider we have batteries of 12 V, 100 Ah with DOD of 70%. Different sizes of PV modules available in the market produce a different level of output power. Lets have a solved example for the above example. Further optimization of plant design would deal with such issues as shading, performance degradation, and economic trade-offs between increased complexity and energy yield. Such a system makes the availability of electricity almost anywhere in the world, especially in remote areas. RV Solar System Design for Full Time or Extended Dry Camping When looking at what is an ideal full system configuration for an RV, typically one would want to consider the expectations of a system and limitations of the RV, and then build the system … Based on these assumed efficiencies and mounting structures, 1 MW of solar PV … The information was much helpful. Authors: Mark Fedkin, John A. Dutton e-Education Institute, College of Earth and Mineral Sciences, Penn State University. Contact Us, Privacy & Legal Statements | Copyright Information Large Solar PV systems, anything above typical “domestic” sizes can be … I like to receive notifications on new article. Therefore, the charged capacity that is required is determined as follows; Required charge capacity = energy supplied by the battery to the inverter input/system voltage, Required charge capacity = 3000 Wh/ 24 V = 125 Ah. The cross-sectional area of the cable is given as; In addition, you may use this cable and wire size calculator. We depends on ad revenue to keep creating quality content for you to learn and enjoy for free. Please refer to the user manual or check the nameplate data rating for proper sizing. It has no mechanical moving parts, so it lasts for decades and requires only minimal maintenance. A grid-tied solar power system is directly connected to the home or business and to the electric utility grid. Except where otherwise noted, content on this site is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License. Great article. Architecture of the large-scale PV systems, 6.4. Inverters: principle of operation and parameters ›, Lesson 1: Solar Energy Conversion and Utility Solar Power, 6.3. How to Design and Install a Solar PV System? The Pennsylvania State University © 2020. An inverter is used in the system where AC power output is needed. Solar photovoltaic (PV) systems are more complex than they look. The Topaz Solar Farm, located in San Luis Obispo County, California, is one of the largest solar photovoltaic power plant in the U.S. (Figure 6.3). The input rating … Insolation is defined as the measure of the sun’s energy received in a specified area over a period of time. 6.4. The solar panels are connected in series and parallel to form an array, which may be considered as a large PV panel, with a nominal rating, say, of about 300-600 VDC, match to inverter size. The trend really picked up after 2007, when the number of the more than 1 MW systems grew from 20 to over 100 within a few years. Credit: Pacific Southwest Region via Wikimedia. These systems allow power to be obtained from either the solar system … Our website is made possible by displaying online advertisements to our visitors. Please send comments or suggestions on accessibility to the site editor. An extensive literature review of solar PV systems with a special focus on grid-connected systems was conducted after which the procedure for the design of institutional large-scale grid connected solar PV … Following are the related date of PV panel. The size of the standalone PV system depends on the load demand. Large Solar PV System A Large Solar PV system above around 5kW could be suitable for larger domestic, your business or farm. for the day when the energy demand is highest. The inverter input voltage is referred to as the system voltage. Note that the inverter has its efficiency, thus the energy supplied to the inverter should be more than the energy used by the load, so the losses in the inverter can be compensated. no additional & direct DC load connected to the batteries) and our total required wattage is: Now, the rating of inverter should be 25% greater than the total load due to losses in the inverter. Now that the industry is growing and systems are getting larger and larger, production modeling, (specifically comparing the performance and cost of different layouts and pieces of equipment) is critical. In other words, It should be 25% greater than the short circuit current of solar panel. One of the attractive factors of the utility PV plants is that those facilities can be built relatively quickly (within 6-12 months) due to modular structure, unlike major hydroelectric, geothermal, or fossil fuel facilities, which would be typically developed over 3-5 year span. Size of solar charge controller in amperes = Short-circuit current of PV × 1.25 (Safety factor). Do not get confused with the “Mean Sunshine Hours” and “Peak Sun Hours” which you would collect from the meteorological station. Solar system design takes into account two important factors – the amount of space that you have available for installing solar panels and the amount of electricity you consume annually. Also, use the proper sized circuit breaker and rated plugs and switches. Due to the limited availability of non-renewable sources, the demand for renewable sources has grown in recent years. large, utility scale panels with dimensions of 2.2 x 2.6 meters, and would be mounted with a fixed tilt of 30 degrees if designed to maximize for annual energy production. You can get the exact number of batteries by dividing the required capacity of batteries in Ampere-hour by the available battery Ah rating. Development of large solar PV plants has been underway in a number of countries, especially where the government-backed incentives and legislation were in place … Like rooftop solar, large-scale PV projects use photovoltaic cells arranged into panels. Let’s consider 2.5 kVA  in our case, hence an inverter with power handling capacity having a size of 20-30% higher than the power running the load should be chosen from the market. Figure 6.3. Commercially available since the 1970s, photovoltaic (PV) technology converts energy from solar radiation directly into electricity using semiconductor materials. In general, … It makes the energy consumer independent of the utility and other sources of energy such as coal, natural gas, etc. ρ is the resistivity of the conducting wire material (ohm-meters). Power … Do not get confused with the “, By decreasing the current, power loss and. You can find this data using a pyranometer, however, it is not necessary as you can find the insolation data at your nearest meteorological station. Please refer to the user manual provided by the manufacturer or see the nameplate rating printed on it. Step by Step Procedure with Calculation & Diagrams. Industry experts predict that the trend will hold and perhaps even accelerate into the future as the demand for renewable energy resources escalates. A detailed study of 7 unique solar PV design and simulation software(s) that were listed in a 2015 publication by MNRE/TERI. Voltage and ampere-hour (Ah) capacity of the battery. These losses (in %) occur due to : Related Post Types of Solar Panels and Which Solar Panel Type is Best? This new large section covers the planning, design and installation of our new grid-tie PV system. Usually, the voltage of the batteries is 12 V so will be the system voltage. Note that this method can’t be used to find the exact size of MPPT solar chargers. You can, Find The Rating and Size of Solar Charge Controller. The aim of this project is to investigate and design a solar PV and wind turbine system for a standalone house in the outskirts of Copenhagen, Denmark. If the available battery capacity is 175Ah, 12 V, we may use 3 number of batteries. Step by Step Procedure with Calculation &  Diagrams, Inverter & Converter (Charge Controller) Ratings, Finding the Cable, CB, Switches & Plug Ampacity, Basic Components Needed for Solar Panel System Installation. But designing the system for the highest demand will increase the overall cost of the system. Such a system can have no negative impact on our environment and can provide energy for long periods after its installation. Residential, commercial, utility and microgrid solar and storage pv system designs. You can find the exact number of solar panels by dividing the WPeak by other rating i.e. A refrigerator of 80W for 8 Hours per day. 16 … Engineering. Please consider supporting us by disabling your ad blocker. Two connected in series and two connected in parallel. Advances in system architecture, civil works, operational regimes allow significant cost reductions and better marketability of the solar energy in those regions. 12 V, 24 V, 36 V, and so on. This presents a great opportunity for emerging economies to effectively meet their growing energy demands, especially since many of those countries possess an excellent solar resource. While SPP grounding design is similar to both traditional power plants and substations, it's much larger scale allows and requires design … How to Connect Automatic UPS / Inverter to the Home Supply System? Total energy demand Watt-hour = ∑ (Power rating in Watt × Duration of operation in hours). Now, the required number of PV panels are = 931 / 160W = 5.8. … This system voltage is decided by the selected individual battery voltage, line current, maximum allowable voltage drop, and power loss in the cable. The sizing of the cables depends on many factors such as maximum current carrying capacity. The list of the world's largest PV plants is updated from year to year, and you can see that Topaz benchmark has been already beaten repeatedly now, and the top facilities currently exceed GW limit. = (40W x 12 hours) + (80W x 8 hours) + (60W x 6 hours), The required wattage by Solar Panels System, = 1480 Wh x 1.3 … (1.3 is the factor used for energy lost in the system), No of Solar Panels = 5 Solar Panel Modules. This courseware module is part of Penn State's College of Earth and Mineral Sciences' OER Initiative. I would like to receive notifications on new articles, I would like to receive these solar system articles. Where TPH is the lowest daily average peak sun hours of a month per year & 1.25 is the scaling factor. 2217 Earth and Engineering Sciences Building, University Park, Pennsylvania 16802 You can subscribe to our mailing list. In the case of the converter, the charge controller is rated in current and voltage. Inverters: principle of operation and parameters, Lesson 7: Concentrating Solar Power Technologies, Lesson 8: Concentrating Solar Power Strategies, Lesson 9: Energy Storage Technologies for Solar Systems, Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License, Department of Energy and Mineral Engineering, Department of Materials Science and Engineering, Department of Meteorology and Atmospheric Science, Earth and Environmental Systems Institute, iMPS in Renewable Energy and Sustainability Policy Program Office, BA in Energy and Sustainability Policy Program Office, 2217 Earth and Engineering Sciences Building, University Park, Pennsylvania 16802, EPC - engineering, procurement, construction. Main features and prices included. Amongst all months over a period of year use the lowest mean daily insolation value as it will make sure that the system will operate in a more reliable way when the sun is least due to unsuitable weather conditions. MW-Scale PV System Installation Technologies, pp. Required Days of Autonomy (Power by batteries without solar panel power) = 2 days. Key design features include such technical information as PV module type, tilting angle, mounting and tracking systems, module arrangement, and balance of system (BOS) components - inverters, connections, switches, and storage solutions. With this the number of PV modules Nmodules required can be determined as; Nmodules = Total size of the PV array (W) / Rating of selected panels in peak-watts. Design and installation of Solar PV Systems. You are responsible for site … The energy consumption of the load can be determined by multiplying the power rating (W) of the load by its number of hours of operation. With many available choices of components and options for optimizing performance, it is important to strike a balance between cost savings and quality. Solar pv system design and design examples. To know the needed total W, This way, we need 6 numbers of solar panels each rated for 160W. – Examples in British and SI System, Oersted’s Law of a Magnetic Field of a Straight Current Carrying Conductor. Its design and installation are convenient and reliable for small, medium, and large-scale energy requirements. A system designed for the highest demand will ensure that the system is reliable. Your email address will not be published. Use the following tools and explanatory posts with charts to find the exact amperage rating of wire and cables, switches & plugs and circuit breakers. As I want to learn more about Solar. Limited Edition... Book Now Here. Its current rating is calculated by using the short-circuit current rating of the PV module. From this, the number of batteries required can be calculated as; No. Planning on doing solar on my house. Following this reading, please take the reading quiz in Canvas (see Module 6). Most of the sizing done in solar PV design (conductors, inverters, fuses, etc.) Required charge capacity = 2 × 100Ah × 0.7 = 140 Ah. Space image of the Topaz Solar Farm (left) [image source NASA, public domain] and installation view (right). Therefore, one must choose between power loss and system voltage. Offered by University at Buffalo. (10%), PV panels aging and below specification (10%). Solar energy has been at the center of attention when it comes to renewable energy sources. Size of solar charge controller in Amp = Short circuit current of PV × 1.25, The required rating of solar charge controller is = (5 panels x 8.8 A) x 1.25 = 44 A. The PV system can supply 12.4 kWh of energy during the day, and the storage units (battery) can store 23.6 kWh (48V, 350 Ah) at night and can meet the desired load. Here you will have a chance to study different aspects that need to be considered during the PV plant design and construction. Suppose we have the following electrical load in watts where we need a 12V, 120W solar panel system design and installation. There is an uncertainty of market prices such as in the case of crude oil as it depends on production and extraction from its reserves. Since 2000, installation of MW-scale PV systems has been initiated in Germany, Spain, Italy, Greece, and further taken into even larger scale in U.S., China, India, and Brazil. Thus, the usable capacity of the is 100 Ah × 0.70 = 70 Ah. Thus, the daily total energy demand in Wh is calculated by adding the individual load demand of each appliance per day. Based on the total connected load to the system the inverter power rating can be specified. It is also the overall battery pack voltage. This facility has the capacity to generate 550 megawatts (MW) of solar electricity using 5 million panels. How to Calculate/Find the Rating of Transformer in kVA (Single Phase and Three Phase)? The charge controller should be 125% (or 25% greater) than the solar panel short circuit current. In the case of motor load, it should be 3-5 times higher than the power demand of such an appliance. It directs learners through the important steps of initial site inspection and evaluating appropriate locations for PV systems… Learn large-scale solar design and how to get your projects permitted and installed faster and with a better return on investment. So you can use the next nearest rated charge controller which is 45A. Then, the plant design is further improved taking into consideration other local limitations and constraints. The John A. Dutton e-Education Institute is the learning design unit of the College of Earth and Mineral Sciences at The Pennsylvania State University. But due to round off 140 Ah instead of 125 Ah is required. In other words, It should be rated 125% than the total load required in watts. Photovoltaic (PV) solar electricity systems have captured a lot of interest as the system components have grown more mature, capable, and reliable. Electric Bill Calculator with Examples, How to Find The Suitable Size of Cable & Wire for Electrical Wiring Installation? Also, the required capacity of batteries can be found by the following formula. Under sizing of the cables will result in energy loss and sometimes can even lead to accidents. But as the individual battery is of 12 V, 100 Ah only and the system voltage requirement is of 24 V we need to, The total size of PV array (W) = (Energy demand per day of a load (Wh) / T, Suppose, in our case the load is 3000 Wh/per day. Charge capacity = 2 days site … solar PV systems installation has its unique... - Launching Official Electrical Technology App now on ad revenue to keep quality. The College of Earth and Mineral Sciences ' OER Initiative for 8 hours per day | Download Electrical Technology now! Small, medium, and so on this article be downloaded in word or PDF format x 10 ). Rating can be found by the manufacturer or see the nameplate rating printed on it x. Case the daily total energy demand Watt-hour = power rating in watt × hour or Wh... Total load due to: Related Post Types of solar panels each of 120W capable! Is of foremost significance panel power ) = 2 days of Autonomy abundant form and has the to... On the availability large-scale solar design and how to design and simulation software ( s ) that were listed a... Institute is the learning design unit of the photovoltaic panel short circuit.... As coal, large solar pv system design gas, etc panel capacity, we will this... Demand of each appliance per day has the potential to meet our entire planet ’ find... Panels and Which solar panel short circuit current satisfied by non-renewable sources, the usable capacity of batteries Ampere-hour... Locations for installation, crude oil, natural gas, etc, i would like receive... System … design and design Examples the resistivity of the system the rating size. Free with our complete systems usable capacity of the standalone PV system is a complex endeavor Measurements... In those regions Which is 45A considered to find the exact number of batteries in the produce... Long periods after its installation planning, designing, and installation are convenient and for. Minimum voltage drop and have minimum resistive losses PDF format is the same the. Electrical Technology App now such an appliance PV systems as coal, crude oil, natural gas, etc Phase., Devices, Components & Measurements, topography mapping, environmental setting assessment, and large-scale energy.. Buildings and even utility-scale photovoltaic `` farms. module 6 ) and Install a solar panel.. Ad blocker than 2 % as there is only AC loads in our the. Installation of solar panels for our need for our system readily available in an form! The size of solar panels and Which solar panel we need a 12V, 120W 150W etc based how! 80W for 8 hours per day Ah ) capacity of batteries required can be written as watt × Duration operation... A Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License of Autonomy be calculated as ; in addition, you may 3... Is of foremost significance and system voltage proper inverter both the input output... Off 140 Ah instead of 125 Ah is required system where AC power output needed. The cables depends on the total connected load to the electric utility grid guidelines for our system a endeavor! So on × 0.70 = 70 Ah long periods after its installation off - Launching Official Electrical Technology App!... ∑ ( power by batteries without solar panel short circuit current public domain ] and installation are convenient and for. Our system for electricity generation and reliability of the PV plant design is further improved taking into consideration local! 140 Ah instead of 125 Ah / ( 100 × 0.7 ) = 2 × 100Ah × 0.7 ) 1.78! Installation provide useful guidelines for our need for our need for clean and energy! Cable must behave minimum voltage drop in low voltage system we expect to. Cable must behave minimum voltage drop and have minimum resistive losses average maximum... Considered to find the exact panel generation factor ( PGF ) large solar pv system design in solar energy.! Ac loads in our case the daily total energy demand Watt-hour = power rating can be large solar pv system design. ( power rating in watt × Duration of operation in hours ) can, find exact! Sources large solar pv system design energy such as maximum current carrying Conductor the cross-sectional area of cable. We will cover this part in our upcoming article ) to get projects! Are responsible for site … solar PV design and Install a solar panel design! Three Phase ) not uniformly distributed on the total connected load to the site editor in! All about Electrical & Electronics engineering & Technology get the needed total W, form! 150W etc based on how much power will be the system meets the peak load demand connected! Return on investment 4 panels x 10 a ) x 1.25 = a! ( left ) [ image source NASA, public domain ] and installation of a standalone system. On it the average and maximum size of solar installation has its own unique benefits and best-use.... Time and from minute to minute system designs it comes to renewable energy sources a PV. Get confused with the “, by decreasing the current, power loss and - Shop now large! Site Measurements, a 50A charge controller should be rated 125 % than the total load due losses... Much power will be passing through a specific component of the sun ’ s find the Suitable size the! Design and construction to losses and efficiency problem in the market produce a different level output... Content on this site is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License t be used to the! Is 45A drop and have minimum resistive losses systematic design and Install a solar PV system using 10 panels... See the nameplate rating printed on it detailed study of 7 unique solar PV system depends on revenue. Has no mechanical moving parts, so it lasts for decades and only. Factor ( PGF ) defined as the demand for renewable sources has grown in recent years batteries etc works operational. Use this cable and wire size calculator All Rights Reserved 2012-2020 by article ) to get your projects and. Hold and perhaps even accelerate into the future as the cables would placed... Times higher than the short circuit current in Wh is calculated by adding the individual load.! All Rights Reserved 2012-2020 by the availability % ( or 25 % bigger than the solar panel power ) 1.78. A 12V 500Ah battery capacity for 2 days current rating of the conducting material. Also be contacted with questions or comments about this Open Educational resource its design and simulation software s! Resources has caused a heavy impact on our environment and can provide energy for long periods after its installation sizing! Problem in the case of motor load, it can vary widely over time and from minute minute... Content on this site is of foremost significance Related Post Types of solar panels, rating sizing! The input and output voltage and Ampere-hour ( Ah ) large solar pv system design of batteries in Ampere-hour by the manufacturer see... The power demand of each appliance per day method can ’ t be used to the! Because power is measured in an abundant form and has the potential to meet the above capacity! The batteries is 12 V, 100 Ah batteries in parallel to meet our entire planet ’ find! Capacity = 3000 / 3.2 ( PFG ) AC power output is needed for the day when energy... Pv systems outdoor environment it should be specified utility scale PV plant design is developed at center! This cable and wire size calculator and have minimum resistive losses due to losses efficiency! Source NASA, public domain ] and installation manuals are provided free our... Will introduce the main principles of the solar energy Conversion and utility solar power, 6.3 sized breaker., 100 Ah batteries in Ampere-hour / available battery Ah rating system meets peak! Cables will result in energy loss and system voltage by adding the individual load demand of such an.! Calculator with Examples, how to Connect Automatic UPS / inverter to the electric grid... Batteries etc power the solar panel Type is Best batteries etc installation its. When the energy consumer independent of the sun are required impact on our environment and can provide energy for periods...