Types of energy resources
Energy, in physics, the capacity for doing work. It may exist in potential, kinetic, thermal, electrical, chemical, nuclear, or other various forms. … Hence, heat transferred may become thermal energy, while work done may manifest itself in the form of mechanical energy. energy is the quantitative property that must be transferred to an object in order to perform work on, or to heat, the object.[note 1] Energy is a conserved quantity; the law of conservation of energy states that energy can be converted in form, but not created or destroyed. The SI unit of energy is the joule.
#Non renewable energy resources
Nonrenewable resources are resources that have a limited supply. More than that, these resources can’t be replaced by natural means at a pace that meets its consumption. A lot of our fossil fuels, such as oil, are nonrenewable resources. In other words, if we keep using them, they will eventually run out.In many of the examples of nonrenewable resources below, the supply comes from the Earth itself. However, since it typically takes millions of years to develop, these resources are finite. Nonrenewable energy can generally be separated into two main categories: fossil fuels and nuclear fuels.
Crude oil is a nonrenewable resource that builds up in liquid form between the layers of the Earth’s crust. It’s retrieved by drilling into the ground and ocean floor, and pumping the liquid out. The liquid is then refined and used to create many different products.
Crude oil is a very versatile fuel and is used to produce things like plastics, artificial food flavorings, heating oil, petrol, diesel, jet fuel, and propane. The top three oil-producing countries are Russia, Saudi Arabia, and the United States.
Petroleum deposits that begin to form underground are known as oil sands, bitumen, or bituminous sands. Bitumen is too thick to be pumped under natural conditions. Scientists refer to it as cold molasses. With special machinery, much of this is being mined in Alberta, Canada, serving as a major energy source for Canadians as well as people all around the world.
Natural gas gathers below the Earth’s crust and, like crude oil, must be drilled for and pumped out. Methane and ethane are the most common types of gasses obtained through this process. These gases are most commonly used in home heating as well as gas ovens, stoves, and grills. Russia, Iran, and Qatar are the countries with the largest recorded natural gas reserves.
Coal is the last of the major fossil fuels. Created by compressed organic matter, it is solid like rock and is obtained via mining. Out of all countries, China produces the most coal by far. In fact, it has been the largest producer of coal for the last three decades, producing more than 3 billion tons of coal each year. Coal is most typically used in home heating and the running of power plants.
#Renewable energy resources
Renewableenergy is energy that is collected from renewable resources, which are naturally replenished on a human timescale, such as sunlight, wind, rain, tides, waves, and geothermal heat. Renewable energy often provides energy in four important areas: electricity generation, air and water heating/cooling, transportation, and rural (off-grid) energy services.
Solar energy is derived by capturing radiant energy from sunlight and converting it into heat, electricity, or hot water. Photovoltaic (PV) systems can convert direct sunlight into electricity through the use of solar cells.
One of the benefits of solar energy is that sunlight is functionally endless. With the technology to harvest it, there is a limitless supply of solar energy, meaning it could render fossil fuels obsolete. Relying on solar energy rather than fossil fuels also helps us improve public health and environmental conditions. In the long term, solar energy could also eliminate energy costs, and in the short term, reduce your energy bills. Many federal local, state, and federal governments also incentivize the investment in solar energy by providing rebates or tax credits.
Although solar energy will save you money in the long run, it tends to be a significant upfront cost and is an unrealistic expenses for most households. For personal homes, homeowners also need to have the ample sunlight and space to arrange their solar panels, which limits who can realistically adopt this technology at the individual level.
Wind farms capture the energy of wind flow by using turbines and converting it into electricity. There are several forms of systems used to convert wind energy and each vary. Commercial grade wind-powered generating systems can power many different organizations, while single-wind turbines are used to help supplement pre-existing energy organizations. Another form is utility-scale wind farms, which are purchased by contract or wholesale. Technically, wind energy is a form of solar energy. The phenomenon we call “wind” is caused by the differences in temperature in the atmosphere combined with the rotation of Earth and the geography of the planet.
Wind energy is a clean energy source, which means that it doesn’t pollute the air like other forms of energy. Wind energy doesn’t produce carbon dioxide, or release any harmful products that can cause environmental degradation or negatively affect human health like smog, acid rain, or other heat-trapping gases.Investment in wind energy technology can also open up new avenues for jobs and job training, as the turbines on farms need to be serviced and maintained to keep running.
Since wind farms tend to be built in rural or remote areas, they are usually far from bustling cities where the electricity is needed most. Wind energy must be transported via transition lines, leading to higher costs. Although wind turbines produce very little pollution, some cities oppose them since they dominate skylines and generate noise. Wind turbines also threaten local wildlife like birds, which are sometimes killed by striking the arms of the turbine while flying.
Dams are what people most associate when it comes to hydroelectric power. Water flows through the dam’s turbines to produce electricity, known as pumped-storage hydropower. Run-of-river hydropower uses a channel to funnel water through rather than powering it through a dam.
Hydroelectric power is very versatile and can be generated using both large scale projects, like the Hoover Dam, and small scale projects like underwater turbines and lower dams on small rivers and streams. Hydroelectric power does not generate pollution, and therefore is a much more environmentally-friendly energy option for our environment.
Most U.S. hydroelectricity facilities use more energy than they are able to produce for consumption. The storage systems may need to use fossil fuel to pump water. Although hydroelectric power does not pollute the air, it disrupts waterways and negatively affects the animals that live in them, changing water levels, currents, and migration paths for many fish and other freshwater ecosystems.
Geothermal heat is heat that is trapped beneath the earth’s crust from the formation of the Earth 4.5 billion years ago and from radioactive decay. Sometimes large amounts of this heat escapes naturally, but all at once, resulting in familiar occurrences, such as volcanic eruptions and geysers. This heat can be captured and used to produce geothermal energy by using steam that comes from the heated water pumping below the surface, which then rises to the top and can be used to operate a turbine.
Geothermal energy is not as common as other types of renewable energy sources, but it has a significant potential for energy supply. Since it can be built underground, it leaves very little footprint on land. Geothermal energy is naturally replenished and therefore does not run a risk of depleting (on a human timescale).
Cost plays a major factor when it comes to disadvantages of geothermal energy. Not only is it costly to build the infrastructure, but another major concern is its vulnerability to earthquakes in certain regions of the world.
The ocean can produce two types of energy: thermal and mechanical. Ocean thermal energy relies on warm water surface temperatures to generate energy through a variety of different systems. Ocean mechanical energy uses the ebbs and flows of the tides to generate energy, which is created by the earth’s rotation and gravity from the moon.
Unlike other forms of renewable energy, wave energy is predictable and it’s easy to estimate the amount of energy that will be produced. Instead of relying on varying factors, such as sun and wind, wave energy is much more consistent. This type of renewable energy is also abundant, the most populated cities tend to be near oceans and harbors, making it easier to harness this energy for the local population. The potential of wave energy is an astounding as yet untapped energy resource with an estimated ability to produce 2640 TWh/yr. Just 1 TWh/yr of energy can power around 93,850 average U.S. homes with power annually, or about twice than the number of homes that currently exist in the U.S. at present.
Those who live near the ocean definitely benefit from wave energy, but those who live in landlocked states won’t have ready access to this energy. Another disadvantage to ocean energy is that it can disturb the ocean’s many delicate ecosystems. Although it is a very clean source of energy, large machinery needs to be built nearby to help capture this form energy, which can cause disruptions to the ocean floor and the sea life that habitats it. Another factor to consider is weather, when rough weather occurs it changes the consistency of the waves, thus producing lower energy output when compared to normal waves without stormy weather.
Hydrogen needs to be combined with other elements, such as oxygen to make water as it does not occur naturally as a gas on its own. When hydrogen is separated from another element it can be used for both fuel and electricity.
Hydrogen can be used as a clean burning fuel, which leads to less pollution and a cleaner environment. It can also be used for fuel cells which are similar to batteries and can be used for powering an electric motor.
Since hydrogen needs energy to be produced, it is inefficient when it comes to preventing pollution.
Bioenergy is a renewable energy derived from biomass. Biomass is organic matter that comes from recently living plants and organisms. Using wood in your fireplace is an example of biomass that most people are familiar with.
There are various methods used to generate energy through the use of biomass. This can be done by burning biomass, or harnessing methane gas which is produced by the natural decomposition of organic materials in ponds or even landfills.
The use of biomass in energy production creates carbon dioxide that is put into the air, but the regeneration of plants consumes the same amount of carbon dioxide, which is said to create a balanced atmosphere. Biomass can be used in a number of different ways in our daily lives, not only for personal use, but businesses as well. In 2017, energy from biomass made up about 5% of the total energy used in the U.S. This energy came from wood, biofuels like ethanol, and energy generated from methane captured from landfills or by burning municipal waste.
Industries use a large amount of energy to power a diverse range of manufacturing and resource extraction processes. Many industrial processes require large amounts of heat and mechanical power, most of which is delivered as natural gas, petroleum fuels, and electricity. In addition some industries generate fuel from waste products that can be used to provide additional energy.Because industrial processes are so diverse it is impossible to describe the multitude of possible opportunities for energy efficiency in industry. Many depend on the specific technologies and processes in use at each industrial facility. There are, however, a number of processes and energy services that are widely used in many industries.
Various industries generate steam and electricity for subsequent use within their facilities. When electricity is generated, the heat that is produced as a by-product can be captured and used for process steam, heating or other industrial purposes. Conventional electricity generation is about 30% efficient, whereas combined heat and power (also called co-generation) converts up to 90 percent of the fuel into usable energy.Advanced boilers and furnaces can operate at higher temperatures while burning less fuel. These technologies are more efficient and produce fewer pollutants.
Over 45 percent of the fuel used by US manufacturers is burnt to make steam. The typical industrial facility can reduce this energy usage 20 percent (according to the US Department of Energy) by insulating steam and condensate return lines, stopping steam leakage, and maintaining steam traps.
Electric motors usually run at a constant speed, but a variable speed drive allows the motor’s energy output to match the required load. This achieves energy savings ranging from 3 to 60 percent, depending on how the motor is used. Motor coils made of superconducting materials can also reduce energy losses.Motors may also benefit from voltage optimisation.
Industry uses a large number of pumps and compressors of all shapes and sizes and in a wide variety of applications. The efficiency of pumps and compressors depends on many factors but often improvements can be made by implementing better process control and better maintenance practices. Compressors are commonly used to provide compressed air which is used for sand blasting, painting, and other power tools. According to the US Department of Energy, optimizing compressed air systems by installing variable speed drives, along with preventive maintenance to detect and fix air leaks, can improve energy efficiency 20 to 50 percent.
Residental and commercial building
#Status and issues of energy in Nepal
Nepal’s economic and social development is being hampered by its inadequate energy supply. The country does not have its own reserves of gas, coal or oil. Although its most significant energy resource is water, less than one percent of the potential 83,000 megawatts of hydropower is currently harnessed.
Firewood is the predominant energy carrier, counting for more than 70 percent of consumption. However, its use is inefficient and poses a threat to the country’s forests. At the same time, the indoor pollution caused by open hearths in homes presents a hazard to health. Mains electricity is generally only available in urban areas and some 30 percent of the population do not have access to it (CBS 2011).
The hydropower resources must be exploited in an environmentally sound manner. The energy generated should benefit small and micro businesses while improving the standard of living and the health of local people. It should contribute to the protection of forested areas and, by being fed into the national grid, should bring new revenue to the region.
Compared with other countries, Nepal has a high energy consumption in relation to its gross domestic product (GDP). It does not yet have a strategy for sustainable, efficient energy use for either the electricity sector or its main primary energy source, biomass. The power supply is particularly critical during the dry season, during which it is cut off for several hours a day, which has a negative impact on business and private households. Private households, the public sector as well as commerce and industry sector are largely unaware of the economic and ecological advantages of efficient energy use. There are no standards for energy-saving domestic appliances, lighting or products and processes in industrial use.The energy sector is viewed as Nepal’s key sector with regard to future inclusive economic growth and the realisation development goals as formulated in government policy documents. Besides quantitative targets for electricity generation, transmission and distribution the Government reiterates its commitment to sector reforms and the promotion of private sector participation. Further priority is given to extend rural electrification and a commitment towards a more efficient use of energy. Despite continuous endeavors by the Government and support by the Development Partners the energy supply in Nepal is still insufficient, and a significant obstacle for the social and economic development of the country.
Biomass is by far the most utilized primary energy source and the electrification rate of the popul ation is only about 70%, with approx. 63% in rural areas (CBS2011). Nepal’s average annual per capita electricity consumption is about 161 kWh (CBS2013)– one of the lowest consumption in South Asia. Despite its vast hydropower potential, Nepal suffers from a severe and long-lasting electricity supply crisis. The framework conditions and incentives for private investments in power plants are not adequate and a non-cost-covering tariff system discourages efficient electricity use.
Deferred investment in electricity infrastructure has caused scheduled power cuts of up to 16 hours per day during dry season. As this situation is expected to worsen in future, commercial and industrial entities increasingly operate costly diesel generators. The import of petroleum products has exceeded total exports and thereby contributes significantly to Nepal’s trade balance deficit.
In the last decade dissemination of renewable energy in rural areas has been effectively promoted with assistance of the Development Partners. Decentralized electricity generation and biogas installations thereby improve rural living condition and contribute to a more sustainable use of biomass. Rising energy costs and prevailing energy scarcity increase attention to the efficient use of energy. Reasonable potentials for energy efficiency measures have been identified in industry and households as well as public infrastructure.