ECE 4901 Design I Fall Solar Panel & Solar Thermal Heating Project (UConn Spring Valley Farm) Project Proposal

Transcription

1 ECE 4901 Design I Fall 2014 Solar Panel & Solar Thermal Heating Project (UConn Spring Valley Farm) Project Proposal Faheem Dalal (EE), Jorge Llivichuzhca (EE), Stephanie Mesick (EE) Faculty advisor: Dr. Ali Bazzi (ECE)

2 SUMMARY In this proposal we will outline our design solution to the given problem. We will start by introducing the problem, describing the general background and the purpose of this project. Here we will also list all of the requirements that have been requested by the Spring Valley Student Farm to achieve the desired solution. We will then give a description of the project including desired objectives based on the required project specifications and a description of our design solution to the problem. In addition, we would like to talk about the service learning aspect of this project. Here we will describe the outcomes in service learning that we would like to accomplish by implementing our design solution to the project. We will also give a short description of our budget and specify the items that we would like to invest in. Finally, we create a timeline by describing the steps that we will take in order to reach the desired outcomes. BACKGROUND The Spring Valley Farm is part of UConn s Eco House community which is a sustainable learning community. The farm is run by UConn student residents that live in the two houses that are part of the community. The students actively participate by growing organic foods that are distributed to UConn s dining hall services and sold at an on campus farmers market. In addition to the two houses, the farm includes two green houses, a chicken coop, and a utility shed. The small chicken coop uses an electric heat lamp and water heater during the cold months of the winter. A Plexiglass greenhouse uses an electric exhaust fan during the summer months, while in the spring a propane heating system warms air to keep the plants warm. As part of its efforts to create a sustainable learning community and to raise awareness about environmental issues, the Spring Valley Student Farm is interested in supplementing as much of their energy use as possible with energy generated from renewable sources. To accomplish this, they want to install a grid connected solar panel system and replace the current propane hot water system in the greenhouse with a solar thermal water system.

3 PURPOSE OF THE PROJECT UConn has long been recognized as one of the most environmentally friendly universities in the world. 1 To enhance the University s sustainability, Spring Valley Student Farm reached out to the Electrical Engineering department for help determining the feasibility of installing solar panels. With the help of this electrical engineering senior design team, the Spring Valley Farm will come closer to realizing its goal of sustainability. The purpose of this project is to design an electrical system that will reduce the farm s dependence on energy generated from nonrenewable sources. Among the benefits of generating electricity from renewable sources, will be the reduction of the farm s carbon footprint. This will be accomplished by improving the farm s energy efficiency and by harnessing energy from renewable sources. A grid tied solar panel system can transform sunlight into electricity that is then fed back into the electric grid. The amount of energy that the panels generate could offset all of the power consumed by the farm and lead to a decrease in money spent on electricity. Electricity in Connecticut currently has an average cost of about $0.20 per kwh, among the highest rates in the United States 2. The solar thermal system can harness energy from the sun to heat water which will in turn heat the greenhouse during the early spring. This system will decrease the amount of money spent on propane, which has had an average cost of $2.97 per gallon over the past five years in Connecticut 3. These systems will, therefore, not only increase the farm s energy sustainability, but also help the farm become more economically sustainable. A benefit of saving money will be that the farm will have additional money to put toward growing more organic food. Naturally grown organic foods are beneficial to the environment and health of people who consume it 4. Thus, installing renewable energy systems at Spring Valley Student Farm will benefit the University and the surrounding community.

4 OBJECTIVE This project involves two major objectives that we are required to accomplish. The first objective requires data collection and analysis to create appropriately sized designs of photovoltaic (PV) and solar thermal systems. The second objective entails analysis of the environmental impacts and the impact of doing a service learning project with the community. The first objective involves gathering data on the farm s energy consumption. This includes obtaining past electric bills for both houses and propane bills for the greenhouse. Additionally, the amount solar irradiance at the farm must be determined. Irradiance data must take into account the variations in solar energy levels that occur during different times of the year. Once all the data is collected, our objective is to analyze the data to begin designing and sizing both the PV and solar thermal systems. As we develop models for both systems, we will be able to begin fulfilling the second major objective: estimating the efficiency of such renewable energy systems. This will require the installation of a PV prototype for monitoring and data collection. The data will be useful as we assemble a list of products available on the market, along with details on sizing and cost. We will compare multiple renewable energy setups to the farm s current electrical and heating usage and estimate the farm s potential to reduce its carbon footprint. We will also perform a cost analysis of both systems to estimate a payback timeframe. An additional aspect of this objective is to actively participate in service learning. Through frequent communication with the farm s manager, Julia Cartibiano, we learn what the farm needs are in terms of energy so that it can carry out its mission of growing food sustainably. We will, in turn, educate members of the farm community on renewable energy systems. Furthermore, the farm community and this senior design team will share information on how using renewable energy systems can help our local community and how other farms can implement similar systems.

5 DESIGN SOLUTION 1. Increase energy efficiency Since our task is to adapt renewable energy systems to older homes, the first priority is to propose ways for Spring Valley Student Farm to increase its energy efficiency. Upon performing an energy assessment of the farm, we gained a sense of how energy is consumed, noted which energy efficient features were incorporated during renovations, and identified areas where efficiency can be improved. From information on appliance energy consumption, we are working on developing strategies to decrease the farm's energy use and costs. The most severe problem we identified was that the homes' stone basements are under insulated, which leads to heat and energy loss. We recommend that insulation be added to the basement to reduce the amount of heat transferred from the house to the outdoors. Other areas through which air may escape should also be identified and fixed. The team has identified other problem areas by composing an Electrical Energy Consumption Spreadsheet, which includes information on appliance type, electrical ratings, and an estimate of daily usage of appliances. This information will be used to compare the farm's current appliances with energy efficient models. For example, we discovered that the farm has six refrigerators, where four are used to keep the produce they grow cool. One fridge has a wattage rating that is more than 200 W greater than the average rating of the other refrigerators. Therefore, the farm may want to consider replacing this fridge with an energy efficient model. Another recommendation for the farm is to replace all incandescent lights with energy efficient lighting. Replacing 60 W incandescent bulbs with 14 W compact fluorescent bulbs, and 75 W and 100 W incandescent bulbs with 26 W fluorescent bulbs will provide as much light but will be several times more efficient. It is estimated that the farm could use 840 kwh less by switching to compact fluorescent lights 5. Moreover, these efficiency strategies will reduce the farm s energy use and will consequently decrease the necessary size of the renewable energy systems. Implementing these strategies will also reduce greenhouse gas emissions that result from burning fossil fuels as electricity is generated, which is a primary goal of the Spring Valley Student Farm.

6 2. Propose a PV system for all electricity needs From the power bills we received from Uconn Utility services, we have concluded that on average from the four years provided 2010 to 2014(so far), the utilities connected to the meter at 104 spring manor will use on average 2855kWh a year; since this is the only bill we ve received so far we will use this as reference. And even though after calculating the average daily power usage from adding up individual utilities and their approximate run times, we come up with a larger power consumption, we will use the official consumption noted by the bills provided to us [6]. We would need this minimum amount of power to be generated by the solar cells for 104 Spring Manor to be energy independent at least for all electrical appliances used in the house as well as the shed behind the main housing area. We will account for power loss by using the derate factor which is an inductry standard of about.77. This accounts for wiring, shading, inverters etc [7] We also want our solar cells to be tied to the grid, which will not be too much extra work. We can do some rough calculations to predict the minumum solar cell size we will need by using the equation: D aily kw h /Avg peak sun hours / derate factor / panel size = # P anels 2855kW h/365 / 3 /.77 = 3.38kW h This is the amount of power produced Based on the panel size we can decide the number of panels to use. This system would then be connected to a DC AC inverter which would then be connected to power the house and the house meter, which would essentially grid tie this system [8][9]. 3. Proposed solar thermal system for greenhouse water bench heating The Spring Valley farm has one greenhouse that operates during the months of March, April and the rest of the summer. During the months of March and April the greenhouse is heated using propane to heat the air inside the greenhouse. As we know propane can get very expensive and solve this problem our senior design team would like to propose a solution to this problem.

7 Our plan is completely eliminate the greenhouse dependence on propane to heat the greenhouse. We will instead use a solar thermal system that will be used to heat the greenhouse through a pipe heating distribution system. This system will be composed of a solar thermal collector, which will capture energy from the sun by using a coating material that covers a parallel pattern of tubes. Inside the system of tubes there will be an antifreeze solution, we have decided to use this instead of water since water can freeze during the cold months of the winter. An electric pump motor connected to the system will pump the antifreeze. This will ensure that there s a constant flow through the pipes as a closed loop system. The heat from the antifreeze solution will then be transferred to a water storage thank. This water storage thank will then distribute warm water through a system of pipes installed beneath the growing crops acting as a heat sink and warming the soil for the crops to grow. In order for the crops to grow the temperature in the soil needs to be of at least 70 degrees Celsius. In order to ensure that we keep the greenhouse at optimal conditions we will install a thermometer to monitor the temperature. 4. Document data and design a model for sustainable energy for other farms and communities to follow All data and designs will be available for others to see on the senior design website. This data will include our presentation, all power bills, electrical component data, as well as any designs of solar thermal heating or solar cell implementation we will create in the future. Ideally this will give others the opportunity to be able to follow our work and take an initiative to implement similar ideas to their own entities. SERVICE LEARNING We have met with Julia yakovich to discuss our progress so far. In our reflections we discussed our progress, any obstacles, our thoughts about community effect and most importantly planning. Julia has given us insight on community effect pertaining to other entities not just university or agriculture related. She has also given us good advice on planning and role assignment.

8 BUDGET Our budget has been projected to be about $3000 for now with finance coming from two locations. As of now our group has not approved of any purchases due to our still being in the research phase. We do have predicted purchases based on our time constraint. We plan on purchasing a pyranometer primarily for irradiance detection of which data we will require to monitor solar cell activity. However this is not absolutely necessary as some of this data can be found online. The pyranometer is about $400 with a data logger [10]. If purchased this will be useful for future university projects as well. Another purchase we may be able to make during our time under this project is the tubing for a solar thermal heating system within the main greenhouse on Spring Valley farm. Since we are not sure at this point if we will be able to make physical implementation of solar cells onto the farm, we will omit this from our budget report for now. However if we do decide to purchase a solar cell system, we know that this will be a bulk of our budget due to the fact that the materials are costly ( just a 1 kw grid tied system would be upwards above $ ). TIMELINE September (beginning of fall 2014 semester) End of October (now): All electrical components and their power usage have been accounted for [5]. So far we have acquired power bills for 104 Spring Manor, however we do not have bills for the other house as well as propane usage. We have researched: Solar cell sizing as well as grid tied system Solar thermal heating application and sizing Appropriate pyranometer for solar cell monitoring. We have met with Julia Yakovich twice to discuss reflections of this project. We have met with Juli Cartabiano bi weekly for updates and informational meetings.

9 Now December (end of fall 2014 semester) We will visit the Floriculture greenhouse on wednesday November 5, 2014 with Julia Cartabiano to further research solar thermal heating We hope to have all power bills so that we can appropriately size solar cells to provide energy for both houses. As well as appropriate Solar thermal heating sizing for the propane heated greenhouse Meet with Julia yakovich again for further reflections (Meetings TBD) Possibly order a pyranometer from Kip & Zonnen Meet with Joshua brown from National instruments to discuss Solar thermal implementation February(Spring 2015 semester) We would like to implement solar thermal heating to the greenhouse so the spring valley farm will be able to grow food, in the later winter months, that requires a higher temperature. End of spring 2015 semester We hope to be able to implement Grid tied solar panels that will let Spring Valley farm be energy independent, however if this is not achievable, we would like to at least give them a layout of a plan that will aid them in future endeavours to physically implement renewable energy systems.

10 REFERENCES [1] "UConn Is Sierra Club s No. 1 Coolest School." UConn Today. N.p., n.d. Web. 29 Oct [2] U.S. Energy Information Administration, Average Retail Price of Electricity to Ultimate Customers by End Use Sector [3] U.S. Energy Information Administration, Weekly Heating Oil and Propane, [5] Spring Valley Farm Solar Panel Senior Design Team, Electrical Energy Consumption Spreadsheet, Fall [6] Spring Valley Farm Solar Panel Senior Design Team, 104 Spring Manor electricity by quarter, Fall [7] PVWATTS v.1 Derate Factor Calculation (PVWATTS v.1 Derate Factor Calculation) [8] Sizing Your Grid Tie System (Sizing Your Grid Tie System) grid tie systems [9] Basics of How to Size a Photovoltaic Solar Power System Array (Basics of How to Size a Photovoltaic Solar Power System Array) [10] Spring Valley Farm Solar Panel Senior Design Team, Senior Design Project Presentation, Fall 2014.