Use of Energy for transportation

About 28% of the energy Americans use goes to transporting people and goods from one place to another. Cars, vans, and buses are commonly used to carry people. Airplanes, trains and trucks, are used to carry people and freight. Barges and pipelines only carry freight. In 2009, there were about 246 million vehicles (cars, trucks, and buses) in the United States - more than three motor vehicles for every four people.

Cars, light trucks and motorcycles mainly used gasoline; diesel fuel is used mainly by heavier trucks, buses, and trains. Together, gasoline and diesel, and the biofuels ethanol and biodiesel that are added to gasoline and diesel, made up 82% of all the energy used for transportation in the U.S. in 2011.

Hybrid-electric vehicles combine the benefits of gasoline engines and electric motors by reducing the amount of fuel required to move a vehicle. This is why hybrid-electric vehicles can get more miles per gallon of gasoline compared to vehicles that run on gasoline alone.

Automobiles are the most common mode of transportation in the United States. Personal vehicles (like cars and light trucks) consume about 60% of the total energy used for transportation, while commercial vehicles (like large trucks and construction vehicles), mass transit (like airplanes, trains, and buses), and pipelines account for the rest.

Sources of US electricity generation

Most of the electricity in the United States is produced using steam turbines.

In 2011, coal was the fuel for about 42% of the 4 trillion killowatthours of electricity generated in the United States.

Natural gas, in addition to being burned to heat water for steam, can also be burned to produce hot combustion gases that pass directly through a turbine, spinning the turbine's blades to generate electricity. Gas turbines are commonly used when electricity utility usage is in high demand. In 2011, 25% of the Nation's electricity was fueled by natural gas.

Nuclear power is a method in which steam is produced by heating water through a process called nuclear fission. The heat is used to turn water into steam, that, in turn, spins a turbine that generates electricity. Nuclear power was used to generate about 19% of all the Country's electricity in 2011.

Renewable Energy Sources such as Hydropower, Wind Power, Solar Power, Biomass and Geothermal power make up the rest.

Hydropower, the source for 8% of U.S. electricity generation in 2011, is a process in which flowing water is used to spin a turbine connected to a generator.

Wind power is produced by converting wind energy into electricity. Electricity generation from wind has increased significantly in the United States since 1970, but wind power remains a small fraction of U.S. electricity generation, about 3% in 2011.

Solar power is derived from energy from the sun. In 2011, less than 1% of the Nation's electricity was from solar power.

Biomass is material derived from plants or animals that can be burned directly in steam-electric power plants, or converted to gas that can be burned in steam generators, gas turbines, or internal combustion engine-generators. Biomass accounts for about 1% of the electricity generated in the United States.

Geothermal power comes from heat energy buried beneath the surface of the earth. This energy source generated less than 1% of the electricity in the Country in 2011.

US Electricity Consumption

The United States of America (USA) is the world's second largest consumer of electricity. It consumes about 20% of the world's supply of electricity.

Total electrical energy consumption in 2010 was 4,151 Billion Kwhs (B Kwhs).

- 125.7 Million residential customers used 1,446 B Kwhs- 34.8% of USA’s 2010 load. 
- 17.7 Million commercial customers used 1,330 B Kwhs- 32 %. 
- 748.000 Industrial customers used 970 B Kwhs- 23.4%. 

397 Billion Kwhs or 9.6% were losses from the system (135 B Kwhs) and for unaccounted loads (262 B Kwhs). 

Average residential monthly usage was about 959 Kwhs and at a cost of $110.67/month.

Total Consumption in the peak year of 2007 was 4,184.5 B Kwh’s up from 3,836 in 2000.

US Electricity Generation

The United States of America (USA) is the world's second largest producer of electricity.

In 2010 the total installed electricity generation capacity in the United States was 1,137.3 Gigawatts. The main energy sources for electricity generation include:

- Thermal/Fossil 775 GW
- Nuclear 106.7 GW
- Hydropower 98.7 GW
- Wind 39.5 MW

Actual electricity generation in 2010 was 4,125 Terawatt hours from the following sources:

- Thermal/Fossil 2,914 TWh
- Nuclear 807 TWh
- Hydropower 255 TWh
- Other renewables 167 TWh (including landfill gas, geothermal energy, solar and wind).

The share of coal and nuclear in power generation is much higher than their share in installed capacity, because coal and nuclear plants provide base load and thus are running longer hours than natural gas and petroleum plants which typically provide peak load, or than wind turbines or solar plants that cannot produce electricity continuously.

Maintenance and savings of solar water heating systems

Maintenance costs for solar water heating systems are generally very low. Most solar water heating systems come with a five-year or ten-year warranty and require little maintenance. Once fitted your installer should leave written details of any maintenance checks that you can carry out from time to time, ensuring everything is working properly.

Perhaps the most important thing you can check for yourself from time to time is whether there are any leaks. If there are any leaks of anti-freeze (even if you can’t see any liquid) this will have a strong smell. If you notice this you should contact your installer. In general you should keep an eye on your system to check that it is doing what it has been designed to do. If you are not getting hot water or the solar pipe work is cold (when the pump is running) on warm, sunny days then again you should contact your installer. For peace of mind some installation companies offer an annual service check.

You should have your system checked more thoroughly by an accredited installer every 3-7 years, or as specified by your installer. It is likely that after this period of time the anti-freeze that is used to protect your system in the winter months will need to topped up or be replaced as it breaks down over time reducing the performance of your system. Anti-freeze lasts better if the solar water system is used throughout the year and not left unused during the warmest weeks of the year.

The other thing that your installer should check is the pump.  In a well maintained system, pumps can last for more then ten years.

Solar water heating systems can achieve savings on your energy bills.  Based on the results of our recent field trial, typical savings from a well-installed and properly used system are around $90 per year when replacing gas heating and around $130 per year when replacing electric immersion heating; however, savings will vary from user to user.

Typical carbon savings are around 230kgCO2/year when replacing gas and 510kgCO2/year when replacing electric immersion heating.

Under floor heating

Under floor heating is a very elegant and attractive way to warm up the space. Due to its construction, pipeline installation remains invisible and also saves you space. Structurally it is quite different from other heating systems. Temperature regime is quite low and the property must be constructed differently.
This is a radiant heating system that uses water as a carrier of heat. This means that most of the heat across the room is distributed by radiation (by heated bodies and not air) differently from convection (heated air movement) which is the case in conventional radiator systems. Also, it is a low-temperature system, since the temperature of the fluid is a little higher than the required room temperature.

The only aspect of under floor heating systems that can be considered as his flaw is its slowness. It is much more inert and can take a long time from the start of heating until heat in the room can be felt. This can be seen as a flaw as much as an advantage, depending on the use of the premises. For constantly inhabited building, inertia is a plus, because it compensates for temperature changes in the room. For an area that is not used consistently, where the heating necessary from time to time, inertia is flaw.

Under floor heating system can be embed in almost every object. Thermo insulation and ceiling height must be taken into consideration during construction. It is best when under floor heating system is immediately predicted building facility. Built-in doors and windows at the premises must be more attached to the floor for an additional 4 inches, etc. After installing insulation and heat exchanger tubing, we get the required level of floor coverings.

Previously distribution pipe was made of copper pipes. Due to the price of copper now pex and al-pex pipes are increasingly used.

Geothermal heat pumps

Most people use the energy that has been generated from fossil fuels (oil, natural gas, coal or uranium). Since beginning of the energy crisis, these fossil fuels are becoming more expensive.

The only way to alleviate the energy crisis is, on one hand, to conserve energy and, on the other hand, to use the energy that is not generated from fossil fuels. And that is the real purpose of using renewable energy.

Renewable energy is all around us and is free of charge (except biomass). The energy generated from geothermal sources, from the sun or wind can replace the use of primary energy generated from fossil fuels.

Geothermal heat pump works by taking heat from the earth to provide the useful energy for heating homes and provide hot water. Geothermal heat pumps offer excellent energy saving up to 75% of heating energy that can be extracted from the earth. Electricity is used to operate the compressor and the circulation of fluid that exchanges heat.

Closed loop pipes are placed in the ground and filled with glycol antifreeze fluid. The fluid is heated with heat from the ground to about 10-12°C. Then the fluid is transferred to a heat pump where the heat is handed to another medium. Heat pump, with the help of its compressor provides hot water for the heating system.

Geothermal energy is best used for under floor heating, which requires low temperature water for heating the house.

Electricity consumption of heat pump water/water, which includes geothermal heat pump depends on several factors.

  1. Capacity heat pump (heating and air cooling) which depends on the thermal properties of the heated / cooled building (house),
  2. Depths of geothermal probes and soil characteristics, especially soil moisture,
  3. Internal heating installations, temperature regime in which the heating system works
Geothermal heat pumps are the most expensive form of investment in heat pumps and therefore most often used for buildings with heat losses below 50W/m2 heated object which is achieved by insulating the house (walls min 10cm insulation, roof, windows ...).

Quality and reliability greatly depends on the manufacturer of geothermal heat pumps, but we can say that this is a clean and efficient renewable energy source.

An alternative to the earth-to-air heat exchanger is the water to earth heat exchanger. This is typically similar to geothermal heat pump tubing embedded horizontally in the soil to a similar depth of the earth-air heat exchanger. It uses approximately double the length of pipe of 35 mm diameter, e.g., around 80 m compared to an EAHX of 40 m. A heat exchanger coil is placed before the air inlet of the heat recovery ventilator. Typically a brine liquid (heavily salted water) is used as the heat exchanger fluid.

Many European installations are now using this setup due to the ease of installation. No fall or drainage point is required and it is safe because of the reduced risk from mold.

Even though the installation price of a geothermal system can be several times that of an air-source system of the same heating and cooling capacity, the additional costs are returned to you in energy savings in 5 to 10 years. However, it may start paying for itself immediately. If the cost of your geothermal heat pump is rolled into the mortgage for new house construction, the extra $30 a month on your mortgage payment will be offset by the greater savings on your heating and cooling bills. System life is estimated at 25 years for the inside components and 50+ years for the ground loop. While most of the energy improvement tax credits expired at the end of 2012, geothermal tax credits of 30% are still in play. There hasn’t been a better time to invest in a geothermal system. There are approximately 50,000 geothermal heat pumps installed in the United States each year.

Solar Heating

Solar energy is the energy of solar radiation which is applied in the form of light and heat which we are daily bombarded. It's free, primarily pure energy with zero CO2 emissions.

The simplest way is to collect heat energy, using solar collectors that give the heat to the fluid that can be used for heating domestic hot water, swimming pools and possibly under floor heating. 

The basic components of the system are:

- Storage tank - a bivalent or multivalent, with storage from 100 liters up to 1000 liters.
- Solar collectors - plate or vacuum.
- Solar cells.

Solar water heating systems use solar panels, called collectors, fitted to your roof. These collect heat from the sun and use it to heat up water which is stored in a hot water cylinder. A boiler or immersion heater can be used as a back up to heat the water further to reach the temperature you want.

There are two types of solar water heating panels:

- Evacuated tubes
- Flat plate collectors, which can be fixed on the roof tiles or integrated into the roof.

Larger solar panels can also be arranged to provide some contribution to heating your home as well. However, the amount of heat provided is generally very small and it is not normally considered worth while.

Most are in use closed systems for solar heating of water, which consist installation of primary and secondary circuits. Primary circuit is the solar system, which is consisted from solar collector and additional components. Secondary circuit is used for heating hot water over central heating system.

The advantages of this system are very large. The existence of multiple separate boilers in your household is eliminated, and you gain the ability during winter your solar water heater to be heated by the central heating system or by electricity. The operation of the system is fully automated and the entire system is controlled by special automatic. Pay back period depends on the use of the system itself. The solar system is a very economical way of heating.

Energy Efficiency

Under the concept of energy efficiency we mean efficient use of energy in all sectors of final consumption of energy: industry, trade, services, agriculture and households.

Energy efficiency is the sum of planned and implemented measures designed to use the minimum possible amount of energy so that the comfort level and the rate of production remain preserved. Energy efficiency is use less power (energy) to perform the same job - function (heating or cooling, lighting, manufacturing a variety of products, drive vehicles, etc.).

It is important to point out that energy efficiency should not be viewed as saving energy. Namely, saving always involves certain sacrifices, and efficient use of energy never violates the conditions of work and life. Furthermore, improving the efficiency of energy consumption not only involve the application of technical solutions. Moreover, each technology and technical equipment, no matter how effective was, it loses its property unless there are educated people who will know how to use it in the most efficient manner possible.

Therefore, we can say that energy efficiency is primarily a matter of awareness of people and their willingness to change the established habits towards energy efficient solutions, but it is a matter of complex technical solutions. Thus, in making recommendations for improving energy efficiency should first consider the habits of consumers and direct them to the conscientious choices. Such measures are free, and can really make significant savings. Only when the level of consumer awareness of the need for efficient use of energy is developed, is necessary to direct the consumer to the new technical measures to reduce energy consumption, whose application will be decided on the basis of their cost-effectiveness, and thus raise the energy and economic efficiency.

Improved efficiency of energy use will result in its reduced power, thus leading to the reduction of energy production. It can be said that every kWh of energy that is not spend means we save a certain amount of pollutant gases that are released into the atmosphere. Therefore, the effective utilization of energy raises the quality of their own environment and contributes to the global fight against climate change.

Efficient energy use means the use of energy efficient materials, devices, systems, and technologies that are available in the market, with the aim of reducing energy consumption while achieving the same effect (heating, cooling, lighting, cooking process, money ...).

Energy is not free, it spends part of the home (or business) budget - every month for bills for electricity, natural gas, thermal energy from the city's district heating, water. When we add costs of fuel for vehicles, the monthly amount can be significant. Therefore, it is clear that reduced energy consumption due to its efficient use brings proportional financial savings.

Solar Industry Grows 13.2%

The Solar Foundation (TSF) announced encouraging statistics that show the U.S. solar industry is expanding at a clip nearly six times that of the overall economy despite recent setbacks and reports of layoffs.

U.S. solar industry added 13,872 jobs between September 2011 and September 2012 according to TSF. Bringing the total of employed solar industry workers to 119,016, this leap represents a 13.2 growth in employment. In comparison, the overall economy poked along at a sluggish 2.3 percent during the same time period.

“The solar industry has grown at significantly higher rates than most other industries in the past several years, making it one of the foremost creators of new jobs in the United States. These new solar industry jobs are sustainable, cannot be outsourced and play a critical role in our country’s economic recovery”, said Executive Director Andrea Luecke in a press release issued by TSF.

“The solar energy industry is creating jobs in America when we need them most. The rapid growth of jobs in the solar industry clearly demonstrates that smart policies, including the federal investment tax credit, are putting Americans back to work. This is what happens when government provides a stable policy environment. “The private industry does what it does best – creates new jobs for Americans” said Rhone Resch, president and CEO of the Washington, D.C. based non-profit Solar Energy Industries Association (SEIA).

“Continued growth of the U.S. solar industry will hinge greatly upon the protection and expansion of successful state and federal policies, in addition to continued financing for solar projects and operations. This is similar to other industries that have evolved over time. We’ve seen this in the automotive industry, in the IT computer industry, and in telecommunications. It’s a natural progression as an industry matures. You’re going to see consolidations in some sectors” said Monique Hanis, spokesperson for SEIA.

Public perception about the state of the solar industry is another factor critical to that growth, and has recently come under scrutiny due to recent reports of layoffs — but as Hanis points out, the solar companies most impacted by layoffs have been in the manufacturing sector, which accounts for a small percentage of all solar jobs. According to TSF’s 2011 solar census, that percentage was less than 14 percent.

The full report is scheduled to be released on November 14. The research is conducted by TSF and BW Research with assistance from Cornell University. The figures gathered by the National Solar Jobs Census 2012 included a wide range of jobs within the solar industry, for a total of 31 different occupations including manufacturing, sales, installation, and software development. 

Presently, the total installed solar capacity in the U.S. adds up to 5.7 gigawatts (5,700 megawatts). By the end of 2012, it is expected that another 3.2 gigawatts will be added, nearly doubling last year’s growth. Estimates indicate that 2013 will see the addition of another 3.9 gigawatts of solar capacity in the U.S.


April 2014

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Recent Posts

  1. Use of Energy for transportation
    Thursday, November 29, 2012
  2. Sources of US electricity generation
    Tuesday, November 27, 2012
  3. US Electricity Consumption
    Saturday, November 24, 2012
  4. US Electricity Generation
    Thursday, November 22, 2012
  5. Maintenance and savings of solar water heating systems
    Tuesday, November 20, 2012
  6. Under floor heating
    Saturday, November 17, 2012
  7. Geothermal heat pumps
    Thursday, November 15, 2012
  8. Solar Heating
    Tuesday, November 13, 2012
  9. Energy Efficiency
    Saturday, November 10, 2012
  10. Solar Industry Grows 13.2%
    Thursday, November 08, 2012

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