Renewable Energy Technology Design and Appraisal (ABEE4090)

Assignment 2: Design/sizing and Assessment of Renewable Energy Systems

Introduction

This Assignment involves design exercise of three renewable energy systems (a small-scale building integrated wind turbine, a photovoltaic system, and a solar thermal system) for electricity and hot water supply for a typical Care Home for up to 20 residences, at your own choice of location, as follows.

1.   The first part includes theoretical analysis involving analytical calculations to assess the Care Home energy requirement, update solar radiation data of the energy resources assessment (Part 1 of the ABEE4090 assignment, given on 14th  Feb 2025) and design sizing of three renewable energy systems to meet the required building loads as outlined below.

2.   A computer modelling exercise to assess the design completed in section 1, above, and predict the annual energy generation of the renewable energy systems, using a suitable computer simulation program (RETScreen, PVsyst or any appropriate computer model)

3.   Carry out a cost appraisal of the system designed in section  1 above, to find out the financial and environmental feasibility.

The aims ofthe Course work

The project will provide:

  An opportunity to gain knowledge and develop professional skills on weather data analysis, building load assessment, and exercise design sizing of renewable energy systems to meet the required building energy loads at a given climate location.

Project Brief: ABEE4090 Main Assignment

Design sizing of three renewable energy systems

You are asked to carry out a design study of three renewable energy supply systems based on a solar PV system, a small-scale building integrated-wind turbine for electricity generation, and a solar thermal water heating system for hot water supply for a typical care home at your  home village or town. The average number of residences in the care home may be taken as 20 people. The building roof space may be assumed for a building plan to accommodate 20 self-contained rooms, living/seating area, a kitchen, dining area, reception/offices, and visitors, space (See Annex 3). The roof of the building may be considered as flat or tilted roof as appropriate, based on the climate.

Task 1.1         Part 1 - Solar radiation data calculations (already completed)

You are required to update and use the weather data obtained in ABEE4090 Assignment Part 1 of the coursework for use in the design exercise (BEE4090 Main Assignment). You are also required to provide details of site specifications including solar radiation (from Part 1 CW), ambient air temperature, and wind speed data, along with simple diagrams illustrating the proposed building roof (orientation & tilt) space allocated for the PV and the thermal solar arrays and the surrounding scene for the wind turbine installation accompanied by analysed wind speed data and direction (Wind rose) if available.

Task 1.2         Hot water system

Under the Health Technical Memorandum, the minimum hot water temperature in the storage for care homes should be between 55 °C, however at the point of use the water should be thermostat controlled using mixed taps to ensure water temperature between 38 and 41 °C for winter and summer respectively, due to the vulnerability of the users. The hot water use for summer and winter may vary between 40 to 50 litres, respectively, for washing and showering, per patient, including the support person,s need, at tap temperature. For other climates, you may adjust these values to suit your climate hot water requirements. For the heating and cooling purposes, you may use any other software to estimate the building heating or cooling load.

The main water supply temperature for the water heating part could be assumed constant at 18。C in summer and 8oC in winter. Again, in the case of hot and moderate climates, you may choose a temperature range that suits your location.

Typical ambient temperature for summer and winter conditions for cold climates are given in Annex 1, however, you may use any other appropriate data, if necessary, based on your location. These could be downloaded using any appropriate sources and should be properly referenced.

You may use a suitable solar collector type for your design suite, but if you would prefer, you may use any suitable solar collector with specifications given in this link:

https://www.spftesting.info/data/1.kollektoren/?l=en.

1.2.1 Use an appropriate method to determine the total solar array area required to meet the care home hot water requirement. You may optimise your design either on summer or winter load basis and weather conditions, but you are required to explain how to meet any shortage or how to use the surplus energy as a result of your proposed design requirements.

1.2.2 Size a suitable hot water storage tank and propose a suitable configuration for the solar thermal system; detailing the necessary components required to ensure adequate hot water supply, at a temperature range required by the Health Technical Memorandum.

For space heating cooling, these may be determined by the heating and cooling comfort zone of the location.

1.2.3 Calculate the hourly and the total daily energy delivered by the system and the hot

water tank temperature profile for winter and summer months of the year (one day for  each month), using the daily values of the mid of the month as average values for each month.

Task 1.3         Electrical energy systems:

For simplicity, you may assume that the daily average electrical loads ofthe care home for the 6 months of October, November, December, January, February, and March are the same. Similarly, you assume that the building electricity load for the other 6 months of the year (April, May, June, July August, and September) are the same. Assuming that the system is grid connected, you are required to estimate the care home building electricity load profile based on the appliances and the daily operating hours under your chosen location. Consider appropriate appliances for your own location. Example may include, but not limited to space lighting, cooling fans, kettles, washing machine, dish washer, televisions, microwave, fridges, mobile chargers, emergency lights, exits lighting, alarms systems.

Tasks to perform. include:

1.3.1 Use an appropriate method to determine the total PV array area required to meet the required proportion of the building electrical load. Again, you may base your design either on summer or winter load conditions, but you are required to explain how to meet any shortage or how to use the surplus energy as a result of your proposed PV  size.

1.3.2 Select a suitable inverter and any other necessary components for the PV system and propose a suitable configuration for the PV system; detailing specifications of all the components considered for the PV system.

1.3.3 Calculate the hourly and the total daily energy delivered by the system to the load, and  the grid import/export profile for the winter and the summer months (one day for each month) of the year, using the daily values of the mid of the month as average values for each month of the year.

You may use the characteristics of the PV module given in Annex 2, but you may also choose a suitable commercial PV module for your system, based on the climate.

Task 1.4         Wind turbine sizing

For the wind turbine sizing - assume that the variation of the coefficient of performance (CP) of the wind turbine with the wind speed is given by the equation:

CP = 0. 055U - 0.0032U2

Where Uis the wind speed in m/sec. Assume an appropriate overall efficiency for the generator, i.e., the transmission system and the electronic systems including the AC/DC inverter. You may also use a different value for the coefficient of performance of the wind turbine, based on the wind turbine type that you may choose, if available.

1.4.1 You should use Bins or any other appropriate method to arrange the data in a suitable format that will enable you to calculate the annual wind energy production. An excel spreadsheet which will guide you arranging your wind data, for the calculations of the wind energy generation is also available on the Moodle. Wind speed data for a period of one year are given in an excel file which can be downloaded from the Moodle.

1.4.2 Size a suitable wind turbine that may meet part of the electrical energy load following the design of the PV system. Use the wind data analysed in section 1.4.1 to calculate the wind turbine energy production. This should enable you to adjust the size of the wind turbine in relation to the PV system to deliver the required electrical energy for the Care Home at an appropriate cost.

What to calculate for the electrical energy systems?

Determine the PV array area, and wind turbine rotor diameter that would enable the Care Home to provide at least 50% of the annual electricity load from the renewable energy systems. Use a suitable combination of PV array and wind turbine which ensures that at least 60% of the renewable energy is provided using the PV system, and the rest by the wind turbine.

Use the PV system and wind turbine specifications obtained above, to estimate the daily electrical energy output profile for mid-winter and mid-summer months of the year (using mid- month day values as average for each month), annual energy supplied and also the electricity imported or exported to the grid under these conditions. For the wind turbine generation, assume that the data given starts from 1st January of the year.

Although cost may not be the criteria of your design sizing, for the purpose of cost analysis use the current commercial PV and wind turbine costs. Perform a sensitivity analysis of the relative capacity of the PV and the wind turbine that you may propose for the project.

Complete the cost analysis and calculate the unit energy cost of the proposed renewable energy systems and compare this with the current energy supply cost for your chosen location. You may perform. a simple life cycle cost analysis to determine the energy cost and the possible payback periods ofthe renewable energy systems.

C) Design simulation tools analysis

Use a suitable computer design tool (e.g., RETScreen, PVsyst, PVGIS or any other relevant  program) depending on the system, to analyse and predict the power of the systems designed above. Estimate the annual energy production of each system designed above using the computer design tool and compare these with the values obtained using the analytical calculations. Discuss and reflect on any discrepancies in the results.

For the design tool, generate the data using the facilities provided by the design tools program. If necessary, use data from the nearest meteorological station, or download these from any other appropriate software, e.g., NASA website, PVGIS, Meteonorm, WRDC etc.

Final Report

You should write up a report that comprises the above tasks, and should be around 4000 words plus any figures, tables, and appendices. You should present the key results inside the text body, and any further complementary data tables should be presented in the appendix.

Your report  should be submitted electronically to Moodle no later than  3:00 PM on the submission date. This should include the design exercise report and the Excel spreadsheets used for design calculations.

Report Structure:

The design exercise report should be about 4000 words (excluding table of contents, tables and figures captions, references, and appendices), and should have an appropriate and correct structure, which should include:

  Cover Page with Student Name and ID

  Title page which should include the Course Work Title, Student name and ID

  Abstract -Summarising the work carried out

  Contents Page including the Figure and Table list.

  Introduction to the Assignment

  Aims and objectives ofthe Assignment.

  Methods and strategies used to achieve the study outcomes.

  Details of all the tasks completed in the Assignment, with sample calculations

   Results and discussions

  Summary specifications ofthe proposed systems.

  Conclusions summarising the proposed energy system and your own reflections on the design.

  References

  Appendix (if any)

Plagiarism

You are reminded of the need to reference your work appropriately and urged to read the guidance on plagiarism and its avoidance available in the Faculty Postgraduate Student Handbook.

Assessment

This is an individual assignment and therefore should be of your own work. Other people’s work should be clearly appreciated and appropriately referenced. The report will be assessed according to the following criteria:

•   Quality of the work in terms of achieving the objectives ofthe assignment.

•   Evidence of effort made to complete the work, including data search, assumptions made and justifications, calculations, and sample calculations.

•   Critical thinking, discussion, and  reflection on the information presented and their relation to the assignment.

•   Clarity and justifications ofthe arguments presented.

•   Showing awareness and understanding of scientific facts relevant to the module and the assignment.

•   Completion of the tasks assigned in this work.

•   Ability to structure and present the work carried out professionally.

•   Appropriate referencing of materials from other people’s works.