Page 1: Renewable Energy Examination Overview

Section 1: Definitions and Relations

• Global Horizontal Irradiance (GHI): Total solar radiation received by a horizontal surface.

• Direct Normal Irradiance (DNI): Solar radiation received directly when the panel is perpendicular to the sun.

• Diffuse Horizontal Irradiance (DHI): Light scattered by the atmosphere and reflected by clouds, reaching a surface that is not directly from the sun.

Relation between GHI, DNI, and DHI

• Formula:GHI = DHI + DNI * cos(θ)where θ is the solar zenith angle.

Scenario & Configuration of Energy Farm

• Mr. X's requirements for sustainable farming integrated with solar energy:

  • Combine farming with photovoltaic (PV) technology.

  • Construct buildings using PV panels.

  • Install a rooftop solar panel that follows the sun's movement (solar tracker).

• Configuration Type: Standalone configuration or off-grid system.

Page 2: Energy Generation Concepts

Energy Systems

• Agrovoltaics: Combination of agriculture and solar energy on the same land.

• Building Integrated Photovoltaics (BIPV): Buildings constructed with integrated solar panels.

• Solar Tracker: Device that orients solar panels towards the sun.

Off-Grid Solar System Details

• System consists of:

  • PV array

  • Charge controller

  • Battery

  • Inverter

  • DC load and AC load centers.

• Charge Controller: Regulates battery charging and discharging, preventing overload.

Specifications of a Solar Panel

• Characteristics:

  • Ise = 4.48V

  • Vmp = 35.82V

  • Imp = 4.26A

• Energy Calculation:Peak capacity = Vmp x Imp = 35.82V x 4.26A = 150 Wp.

Page 3: PV System Comparisons

Roof Mounted vs Ground Mounted Solar PV Systems

• Roof Mounted:

  • Easier installation, typically lower cost.

  • Limited access for maintenance.

• Ground Mounted:

  • Higher installation cost.

  • Easier access and maintenance.

Differentiation: PCU vs. Inverter

• Power Conditioning Unit (PCU): Integrated control and charging system featuring solar charge controller and inverter.

• Solar Inverter: Converts stored DC from batteries to AC for use in grids or homes.

Page 4: Charge Controller Recommendation

MPPT Charge Controller

• Stands for Maximum Power Point Tracking. It optimizes energy harvest by adjusting the output to match the battery voltage.

• Recommendation: For a 3kW rooftop PV system with a 24V battery, an MPPT controller rated at 125A is suitable.

Advantages & Disadvantages of Lithium-Ion Batteries

• Advantages:

  • Low maintenance

  • Higher energy density

  • Longer lifespan.

• Disadvantages:

  • Higher cost

  • Thermal runaway risks, though minimal with proper installation.

Page 5: Solar Water Pumping System Design

Daily Water Requirement Calculation

• Daily requirement: 7000 liters, depth: 42m.

• Total Dynamic Head (TDH): Comprises the vertical lift and frictional loss.

• Hydraulic Energy Required: 840.35 Wh/day.

• PV Module Calculation: 10 PV panels required of 80 Wp each to meet system requirements.

Power Rating of the Motor

• Required power: 1.1 HP motor for optimal efficiency of the system.

Page 6: PV System Design Considerations

Roof Load Capacity

• Age and structure material affect the roof's load-bearing capacity.

• Design considerations include:

  • Weight of PV system

  • Maintenance access

  • Ventilation and airflow for cooling, especially in hot climates.

PV Standards for Project Testing

• Standards: IEC 61215 and IEC 61646 for testing structure, efficiency, and durability under various conditions.

Page 7: Anti-Islanding Techniques

Detection Methods for Grid-Connected Systems

• Passive Methods: Monitor parameters at the common coupling point and disconnect under abnormal conditions.

• Active Methods: Introduce disturbances to detect islanding and measure the system response.

Importance of Earthing in PV Systems

• Earthing protects equipment and users from faults. Essential for safety in high voltage DC systems.

Page 8: Grid Connected System Cost Design

Components and Cost Breakdown

• Inverter Sizing: Must be 25% higher than the total load, accounting for efficiency losses.

• Module Selection: 1250 panels needed for a 100 kW system, with defined cost estimates totaling approximately 62,30,000 Rs.

Payback Period and Carbon Footprint

• Calculation: Yearly savings from solar energy usage allows for a payback period of 7.5 years, with significant reductions in carbon emissions from coal usage.

Page 9: Maintenance and SCADA Protocols

Standard Operating Procedures for PV Maintenance

• Regular system checks, cleaning of solar cells, and maintenance of electrical components to ensure optimal operation.

Recommended SCADA Protocol

• Protocol: MODBUS for reliable communication and monitoring in SCADA systems. Supports diverse industrial automation products.

Page 10: SCADA Objectives and Performance Criteria

Main Objectives

• Continuous monitoring, data acquisition, control, and automation in power grid management.

Communication and Control

• Effective communication protects against system failures and enhances operational efficiency.

Page 11: Electric Vehicle Charging with Solar

Charging Requirements

• Calculate electricity needed for charging depends on travel distance and efficiency.

• Recommendation: 6 solar panels (400W each) for optimal daily EV charging needs.

Importance of Renewable Sources

• Renewable energy for EV charging reduces dependence on fossil fuels and minimizes grid load during peak demand.

Page 12: PLC vs RTU Differences

Characteristics Comparison

• PLC: Ideal for real-time control with programmability.

• RTU: Effective in remote communications, robust with high reliability in difficult environments.

Page 13: Wind Turbine Generators Comparison

Type A vs. Type B Wind Turbines

• Type A (SCIG): Connected directly and simple, ideal for wind application.

• Type B (WRIG): Limited speed variation but enhanced control through external resistors.

Page 14: Power Development and Speed Calculation

Power Calculation Formula

• Formula: P = 0.6 * Cp * N * A * V^3 yields power estimates.

Page 15: Bioethanol Production Methods

Generation Processes

• 1st Generation: Derived from food stocks like starch.

• 2nd Generation: Utilizes non-food materials such as biomass.

• 3rd Generation: Involves algae for biofuel production.

Page 16: Waste to Energy Technologies

Biogas System Overview

• Utilizing organic waste for energy generation; differentiating between biogas and natural gas.

Clean Energy Contribution

• Biogas offers renewable benefits and fertilizers from waste processing.

Page 17: Agrovoltaics Concepts and Benefits

Agrovoltaics

• Integrated use of land for agriculture and solar energy.

• Benefits: Increased efficiency and reduced greenhouse gas emissions.

Page 18: Hydrogen Production

Methods

• Electrolysis: The primary method for green hydrogen from renewable energy sources.

Differences in Hydrogen Types

• Green Hydrogen: Produced via renewable resources.

• Black Hydrogen: Derived from fossil fuels with significant emissions.

Page 19: Sustainability Practices

6Rs of Sustainability

• Rethink, Refuse, Reduce, Reuse, Recycle, Repair: Practices to emphasize sustainability in daily living.

Concept of Microgrids

• Benefits: Provide localized energy solutions and resilience during outages.