The Types Of Energy Resources

Published Date: 02 Nov 2017

Introduction

Energy has played a key role in the development of human society in a way by adapting to the environment which makes its use inevitable. Development of energy resources therefore becomes essential for agriculture, transportation, communication and other related industries in order to achieve the benchmarks of a developed society. Energy is often related to energy resources such as fuel, petroleum etc, which are the sources of usable energy, as they can easily be transformed to other types of energy sources that would serve a particular useful purpose in the society [1].

Types of Energy resources

Energy resources can be classified into two categories:

Renewable resources

Non-renewable resources

Renewable Resource

Renewable energy resources are those sources that replenish with the passage of time and are thus essentially inexhaustible and sustainable such as solar, wind and biomass energy [2]. In other words, renewable energy is the energy obtained from natural resources such as wind, rain, sunlight, tides, waves and geothermal heat [3].

Renewable energy can further be classified as:

Solar energy

Wind energy

Hydropower

Biomass energy

Solar Energy

Solar energy is the most abundant renewable energy resource .The Earth continuously receives massive amounts of incoming solar radiation at the outer surface of its atmosphere. Almost 31% of the solar radiation is reflected back to space, while the rest is absorbed by the atmosphere, oceans and land. This absorbed solar energy then helps or promotes convection currents and evaporation of the oceans, which in turn drives the wind and water cycles, respectively. In addition, solar energy is converted into chemical energy via photosynthesis and this produces the biomass from which all fossil fuels are derived [4].

Solar energy is converted into useable useful energy by:

Solar collectors

A solar collector is a device used to thermally collect, store, and move solar thermal energy. Essentially, solar collectors are heat exchangers that transfer the energy of incident solar radiation to sensible heat in a working fluid—liquid or air [2].

Photovoltaic Cells

Solar energy can be converted to useful electricity by a photoelectric process that might include photo emissivity, photoconductivity and photovoltaic effect.

Photo emissivity occurs when materials emit electrons in the presence of light. The photoconductive effect refers to the phenomenon whereby an electric current flowing through a substance is increased as a result of light falling on it. While both these photoelectric processes are used in specialist applications, it is the photovoltaic effect which is most widely used to produce electricity from sunlight [4]. Photovoltaic is the direct conversion of sunlight to direct current (dc) electricity through a photocell. Photovoltaic cells are semiconductor devices which can convert the energy in photons of light into dc electrical energy. Most cells are made from single-crystal high-purity silicon and small amounts of trace elements such as boron and phosphorus [2].

Evacuated-Tube Collectors

Evacuated-tube collectors are utilized for solar energy collection by using a collector surface that is suspended in a glass vacuum tube.

The collector’s inside surface of the bottom half of a tube is silvered so that the solar radiation is focused on the collector surface. Vacuum is maintained within the collector to reduce the convection heat losses. Although evacuated-tube collectors can employ liquid as a transfer medium, it is more common for them to utilize a temperature-sensitive fluid, such as methanol, which boils at a relatively low temperature [4].

 b) Wind energy

Wind energy is related to converting wind power into useful form of energy which is accomplished by converting the rotation of turbine blades into electrical currents by means of an electrical generator. Furthermore, windmills provide mechanical power which can also be used as wind pumps, used for water pumping or drainage [3].

There are number of constraints regarding the potential of wind power despite its enormous potential. Most basic would be uneven distribution of wind around the planet. Higher altitudes tend to be windier as compared to the equatorial belt. Similarly, inland continental areas experience less wind than coastal regions. Most of the locations where wind power is generated are locations far from the populated areas, hence, wind energy cannot be fully put to use and cannot be relied upon to supply major part of population’s energy demand. . Consequently, wind power when utilized tends to be used as a ‘top-up’ energy resource in an otherwise conventional energy infrastructure. In some circumstances this can make the harnessing of wind energy uneconomic, as it requires the construction of expensive turbines in addition to the provision of a conventional electricity infrastructure [4].

c) Hydropower

Hydropower is renewable and an efficient energy source in which energy is derived from the movement of water in rivers and oceans which is then used for the operation of various mechanical devices [3].

Hydropower can be further classified as [4]:

Hydroelectric power

Tidal power

Wave power

Hydroelectric power

Hydroelectric power systems make use of the potential energy in the column of water amassed when a river is dammed. The resulting head of water is used to drive a turbine coupled to a generator. The turbine chamber is usually located some distance below the level of the dam in order to maximize the head of water. Water is then run from the dam to the turbine chamber via a large pipe known as a penstock [4]

Tidal power

Tidal power is the only form of energy that is derived directly from the relative motions of the Earth, the moon and the sun. It is the relative position of the moon and sun, in combination with Earth’s rotation that is responsible for generating the tides [4].

Tidal power systems generally utilize a barrage to dam a tidal river or estuary. This enables the tidal waters to be funneled using sluice gates through axial hydroelectric turbine [4]

Wave power

Waves are produced by the wind passing over the sea. The energy in waves has a kinetic component arising from the mass of water in motion and a potential component associated with the peaks and the troughs that are a feature of waves [4].

D) Biomass Energy

Biomass refers to all living and recently dead biological matter that can be used as fuel. It also includes any biodegradable waste material that can be burnt or used to produce fuel. However, it excludes organic material transformed by geological processes into coal or petroleum [4].

The simplest use of biomass is to burn it to produce heat energy. Although substances such as cow dung may be burnt, by far the most common fuel used in this way is wood. A more advanced use of biomass is to process it to produce liquid bio fuels, such as ethanol, for use in internal combustion engines. This can be done by fermenting crops, usually maize or sugar cane, to produce alcohol, which is then distilled. An alternative fuel for the internal combustion engine, biodiesel, can be made chemically altering vegetable oils, such as rape seed oil, so that they can be used in an unmodified diesel engine. Finally, it is possible to gasify solid biomass by heating it in the absence of oxygen, to produce a gaseous fuel [4].

Non-renewable resource

A non-renewable resource is a natural resource which cannot be reproduced, grown, generated, or used on a scale which can sustain its consumption rate; once depleted there will be no more available for future use. Furthermore, non-renewable are resources that are consumed much faster than nature can create them. Fossil fuels (such as coal, petroleum, and natural gas), nuclear power (uranium) and certain aquifers are examples. Metal ores are prime examples of non-renewable resources [5]

3-POLICY AND PLANNING FOR ENERGY CONSERVATION

3.1 Planning

Good planning is a basis and starting point of the energy conservation. The essential elements regarding the planning are as follows [6]:

Strategic goals are only achieved if driven by day-to-day actions.

Focusing on action plans starts with developing an energy policy.

Setting objectives and targets.

Preparing detailed action plans.

Allocating management resources.

Utilizing ESGA (Effective Small Group Activities)

3.2 Energy Policy

There are five attributes of a successful energy policy which are as follows [6]:

Commitment: Top management must show commitment with a personal message involving regular policy review.

Thrust: Provide a new and challenging dimension to energy and environment.

Applicability: Manages and directs on which parts of the organization are covered by the policy.

Implementation: Guidance on how the policy objectives are to be met.

Review: How an organization knows goals have been achieved.

For energy policy to be acceptable the top (or senior) management should convey his/her commitments clearly to others and the expected performance standards should be set out.

3.3 Objectives and Targets

Important factors of the objectives and targets are as follows [6]:

Setting objectives and targets

Objectives can be almost the same as the policy or may have to be set locally which express the desired outcomes of specific policy commitment.

Targets detail performance required to meet objectives, often quantitative

Must be realistic, meaningful and achievable.

Benchmarking may be considered at this stage.

For each part of the organization.

Information from the "Understanding" stage.

Assess waste reduction targets, costs and returns.

Build on management strengths, Identify gaps.

Provide incentives for people at all levels.

3.4 Action Plans

Based on the energy policy and the objectives/targets, actions plans should be made out, consisting of the following [6]:

Keep the program on track.

Operate at different levels, but all should be agreed at appropriate level and "roll up" to the senior manager with overall responsibility for energy.

Relate actions to individual objectives and targets.

Assign actions to specific individuals, with clear deadlines for reporting & completion.

Indicate who is responsible for signing off.

Describe the resources available.

Facilitate budget negotiations and confirm adequate budget provisions have been made.

3.5 Major Points

Major points which should be taken into account are as follows [6]:

Draft a policy statement and have it signed by the head of the organization.

Draft objectives and targets and have these accepted and approved by senior management.

Develop action plans and complete a roles and responsibilities matrix.

Have key people develop individual action plans to guide their day-to-day activities.

Utilize ESGA (Effective Small Group Activities) as much as possible.

Establish monitoring procedures.

3.6 Developing an Effective Energy Policy

An effective energy policy is developed using the following documents [6]:

Published policy document

Statement policy document and the corporate policy that is endorsed by board which specifies goals and objectives.

In- house management documents

Involves a strategic plan outlining what has to be done

3.7 Evaluation

In the evaluation the following aspects should be taken into consideration [6]:

Policy of energy management

Results of implementation

Comparison of the results with KPI

3.7.1 Preparation of evaluation form

In order to achieve the objectives given in the policy it is essential to evaluate the results of

energy management implementation. There should be three levels of evaluation as follows:

Self evaluation – This is an internal evaluation conducted by staff within a section or work unit in every month.

Section Manager Evaluation – This is an evaluation conducted by a section manager or a division manager who takes care of that section in every three months in order to intensity the evaluation.

Top Management Evaluation – This is an evaluation conductible by a top management. The evaluation results obtained will be used for personnel evaluation i.e. for annual increment of staff salary or giving bonus.