Renewable Energy and smart systems.

Presenter: Damion Lawrence, M.Sc., B.Ed.

What is renewable energy?

• Renewable energy is an energy source which can

be replenished naturally and indefinitely and thus

is not going to run out.

Forms of renewable energy

1. Solar Energy

2. Wind Energy

3. Geothermal Energy

4. Bioenergy

5. Hydropower

6. Ocean Energy

7. Hydrogen & Fuel Cells

Solar Energy

• Most renewable energy comes either directly or indirectly from the sun. Sunlight, or solar energy, can be used directly for heating and lighting homes and other buildings, for generating electricity, and for hot water heating, solar cooling, and a variety of commercial and industrial uses.

• Problem: Variable amounts of sunshine.

WIND ENERGY

• The wind is use as the prime mover that turns the wind turbines (wind mill) that is connected to the shaft of the generator producing the mechanical energy that is later converted to electrical energy.

• Problems: large, remote, windy sites are needed. Winds are variable.

HYDROELECTRIC ENERGY RESOURCES

• This employs the use of a generator that uses falling water as the prime mover to turn the generator shaft that provides the mechanical energy which is later converted to electrical energy.

• Problems: Expensive to build. Few areas of the world are suitable.

GEOTHERMAL ENERGY

• This form of energy uses the steam from underground springs or steams that are produced from water that is pumped down to hot rocks deep underground as a prime mover that turns a steam turbine connected to the shaft of a Generator.

• Problems: drilling is expensive and difficult.

Bioenergy

• Bioenergy is the energy from organic matter. . Bioenergy is energy derived from the conversion of biomass where biomass may be used directly as fuel, or processed into liquids and gases.

Hydrogen & Fuel Cells

• They convert hydrogen, or hydrogen-containing fuels, directly into electrical energy plus heat through the electrochemical reaction of hydrogen and oxygen into water.

The Advantages of Renewable Energy

• i. It is sustainable and so will never run out.

• ii. Renewable energy facilities generally require less maintenance than traditional generators.

• iii. Renewable energy technologies are clean sources of energy that have a much lower environmental impact than conventional energy technologies

The Advantages of Renewable Energy

• iv. Produces little or no waste products such as carbon dioxide or other chemical pollutants.

• v. Cost effective.

The Disadvantages of Renewable Energy

I. Difficult to generate the quantities of

electricity that are as large as those produced by traditional fossil fuel generators.

II. Renewable energy often relies on the weather for its source of power.

PHOTOVOLTAIC CELL

• Photovoltaic is a solid-state device that converts sunlight into electricity.

•

PHOTOVOLTAIC CELL •

• Silicon is a material known as a ‘semiconductor’ as it conducts electricity and it is the main material for photovoltaic cells.

•

PHOTOVOLTAIC CELL

• Impurities such as boron or phosphorus are added to this base material. These impurities create the environment for electrons to be freed when sunlight hits the photovoltaic panel. The freeing of electrons leads to the production of electricity.

TYPES OF PHOTOVOLTAIC SYSTEM

I. Stand-Alone System.

II. Grid-Connected System.

III. Flat-Plate System.

IV. Concentrator System.

V. Fixed-Tilt System.

VI. Tracking System.

VII. Hybrid System.

Stand-Alone System

• A PV system that is not connected to the utility grid.

Grid-Connected System

• A PV system tied to the electric utility’s power distribution grid.

Flat-Plate System

• A PV system comprised of modules that are flat in geometry and use natural (unconcentrated) solar irradiance.

Concentrator System

• A PV system comprised of modules that have concentrating optics as part of their structure.

Fixed-Tilt System

• Any PV array with modules at a fixed tilt angle and orientation.

Tracking System

• A PV system with modules mounted on a tracking unit that follows the sun

Hybrid System

• Any system with more than one power source.

Typical Components of PV System

A PV system comprise of :

1. Photovoltaic Array

2. PV Array Disconnect

3. Charge Controller

4. Battery Bank

5. System Meter

6. Main CD Disconnect

7. Inverter

8. AC Panel and Disconnect

Photovoltaic Array

• The system begins with the photovoltaic array that turns the sun's energy into direct current electricity.

PV Array Disconnect

• This allows the array to be disconnected from the rest of the system for maintenance. The PV Array Disconnects main breaker would trip, protecting the components.

Charge Controller

• The primary job of this component is to protect the battery bank from being overcharged. It does so by monitoring the charge levels of the batteries cutting of the current from the PV Array when the batteries are fully charged..

Battery Bank

• This is the bank of batteries used to store the current generated by the solar panel until needed by devices using the power.

System Meter

• Larger systems often have system meters that monitor things like the state of the battery charge, and current utilization by the system.

Main CD Disconnect

• This component does much the same thing as the AC panel found on your home. There is a main breaker that protects the electrical lines going to the devices and the battery bank from current loads in circuits that are abnormal (short) or beyond the capacity of the wiring.

Inverter

• An inverter is a device that converts DC power from the battery bank to AC power for various loads.

AC Panel and Disconnect

• the main breaker will allow the AC lines to be disconnected from the inverter and trip when the AC load exceeds the capacity of the inverter and DC system components.

Design factors

According to the Pacific Power Association (2012 ), the Four major factors that should be considered when designing a PV system are:

1. The type of loads that will be used on the system

2. Charge Controller and Solar Cell’s IV Characteristics

3. Climate

4. Cost .

Photovoltaic applications.

1. Water pumps.

2. Street lights

3. Toys, watches,

calculators

4. Emergency power

5. Portable power

supplies

6. Satellites

7. Residential

Questions & Answers

References

• Daystar, Inc. (n.d). Working Safely with Photovoltaic Systems. Retrieved from: www.wbdg.org/ccb/DOE/TECH/wksafe.pdf‎

• Lewis, A., S. Estefen, J. Huckerby, W. Musial, T. Pontes, J. Torres-Martinez, 2011. Ocean Energy. In IPCC Special Report on Renewable Energy Sources and Climate Change Mitigation. Retrieved from: srren.ipcc- wg3.de/report/IPCC_SRREN_Ch06.pdf

References

• Pacific Power Association Off Grid Pv Power Systems System Design Guidelines. Retrieved from:

http://www.google.com.jm/url?sa=t&rct=j&q=&esrc=s&f rm=1&source=web&cd=1&ved=0CDcQFjAA&url=http%3A%2F %2Fwww.irena.org%2FDocumentDownloads%2Fevents%2F201 3%2FMarch%2FPalau%2F8_OffGrid_DesignGuidelines.pdf&ei= blIPUvC3K7eg4AOMlYDgAg&usg=AFQjCNGaSXpOrmEKXSyQ2JX s2qUrEyD7g&sig2=jOPA0gLP1WQIgeWeMyHn5g&bvm=bv.507 68961,d.dmg

ideo on Renewable Energy Retrieved from: http://www.youtube.com/watch?v=25bmXpEPosc

Video on How a PV system works. Retrieved from: http://www.youtube.com/watch?v=bPE2pBUPjkA