Energy FAQs

The Alternative Energy Revolution – A Status Report

Also get to know how you can benefit this revolution!

1. I have heard that you shouldn’t turn fluorescent lights on and off when I leave my office. Should I turn my lights off to go to a 30-minute meeting? - http://energy.ucsb.edu/EnergyInfo/EnergyFAQs.htm

2. What does "energy conversion efficiency" mean?

Energy conversion efficiency is an expression of the amount of energy produced in proportion to the amount of energy consumed, or available to a device. The sun produces a lot of energy in a wide light spectrum, but we have so far learned to capture only small portions of that spectrum and convert them to electricity using photovoltaics. So, today's commercial PV systems are about 7% to 17% efficient, which might seem low. And many PV systems degrade a little bit (lose efficiency) each year upon prolonged exposure to sunlight. For comparison, a typical fossil fuel generator has an efficiency of about 28%. (from EERE.gov) - Source

3. What are the disadvantages to using solar and renewable energy?

The biggest disadvantage and the only truly significant one remains the cost. For example, solar energy technologies require a significant initial outlay. Still, in nearly all cases, this high initial cost is recovered through substantial fuel savings over the life of the product (15-30 years), and solar energy systems can last much longer than this. The other obvious disadvantage is that if you live in a geography where there is only minimal sunlight, solar systems won’t be that useful.

4. Fusion for Energy FAQ - http://fusionforenergy.europa.eu/faq_en.htm

5. Why don't we put all the wind turbines out to sea?

We will need a mix of both onshore and offshore wind energy to meet the world’s challenging targets on climate change. At present, onshore wind is more economical than development offshore. Furthermore, offshore wind farms take longer to develop, as the sea is inherently a more hostile environment.

6. How does a wind turbine make electricity?

The simplest way to think about this is to imagine that a wind turbine works in exactly the opposite way to a fan. Instead of using electricity to make wind, like a fan, turbines use the wind to make electricity.

Almost all wind turbines producing electricity consist of rotor blades which rotate around a horizontal hub. The hub is connected to a gearbox and generator, which are located inside the nacelle. The nacelle is the large part at the top of the tower where all the electrical components are located.

Most wind turbines have three blades which face into the wind; the wind turns the blades round, this spins the shaft, which connects to a generator and this is where the electricity is made. A generator is a machine that produces electrical energy from mechanical energy, the opposite of an electric motor. Source

7. How much space do wind turbines require?

A typical wind farm of 20 turbines might extend over an area of 1 square kilometre, but only 1% of the land area would be used to house the turbines, electrical infrastructure and access roads; the remainder can be used for other purposes, such as farming or as natural habitat - Source

8. How efficient are wind turbines?

The theoretical maximum energy which a wind turbine can extract from the wind blowing across it is just under 60%, known as the Betz limit. However the meaning of efficiency is a redundant concept to apply to wind energy, where the fuel is free - Source

9. How much does it cost to make electricity from the wind?

Wind energy is one of the cheapest of the renewable energy technologies. It is competitive with new clean coal fired power stations and cheaper than new nuclear power. The cost of wind energy varies according to many factors. An average for a new onshore wind farm in a good location is 3-4 pence per unit, competitive with new coal (2.5-4.5p) and cheaper than new nuclear (4-7p). Electricity from smaller wind farms can be more expensive. See also: Wind Energy and the UK's 10% Target.

10. Could I put a turbine in my garden or on the roof of my house?

11. How can I build my own wind turbine?

http://www.bwea.com/you/siting.html

12. How much electricity does one wind turbine produce?

One 1.8 MW wind turbine at a reasonable site would produce over 4,7 million units of electricity each year, enough to meet the annual needs of over 1,000 households, or to run a computer for over 1,620 years - Source

13. What is ocean energy?

Ocean energy refers to a range of technologies that utilize the oceans to generate electricity. Many ocean technologies are also adaptable to non-impoundment uses in other water bodies such as lakes or rivers. These technologies can be separated into three main categories:

Wave Energy Converters: These systems extract the power of ocean waves and convert it into electricity. Typically, these systems use either a water column or some type of surface or just-below-surface buoy to capture the wave power. In addition to oceans, some lakes may offer sufficient wave activity to support wave energy converter technology.

Tidal/Current: These systems capture the energy of ocean currents below the wave surface and convert them into electricity. Typically, these systems rely on underwater turbines, either horizontal or vertical, which rotate in either the ocean current or changing tide (either one way or bi-directionally), almost like an underwater windmill. These technologies can be sized or adapted for ocean or for use in lakes or non-impounded river sites.

Ocean Thermal Energy Technology (OTEC) OTEC generates electricity through the temperature differential in warmer surface water and colder deep water. Of ocean technologies, OTEC has the most limited applicability in the United States because it requires a 40 degree temperature differential that is typically available in locations like Hawaii and other more tropical climates

Source

14. Is ocean energy commercially viable now?

Yes, but thus far, only on a small scale

15. What about the environmental impact of electricity generation?

NUCLEAR VS. FOSSIL FUELS

* Making electricity contributes 40% of world carbon dioxide emissions.

They and other greenhouse gas emissions from burning fossil fuels trap solar heat in the upper atmosphere that would normally be radiated into space. This process is causing the global temperature to rise. The effects are already having an impact on all life and could cause the extinction of as much as 30% of all species.

* Electricity use is rising in the U.S. and is expected to double before mid-century. From 1990 to 2005, American output of greenhouse gases rose by 17%, with most coming from residential sources.

* On average, an individual American’s contribution is 24.5 metric tons of greenhouse gases a year and growing. Even though Americans make up only 5% of the world’s population, they account for 25% of the world’s total.

* There are only three sources of electricity generation reliable and steady enough to meet 24/7 demand: fossil fuels, hydroelectric dams, and nuclear power.

* Worldwide, 0.02% of our electricity comes from wind and solar power and in the U.S., less than 1%. These systems operate at best only one-third of the time and require backup systems, usually fossil-fuel powered. Until battery storage technology is radically improved, wind and solar power will be able to meet only a fraction of growing electricity needs.

* In the U.S., three-quarters of the electricity comes from burning fossil fuels that emit greenhouse gases.

* To keep a 100-watt bulb burning for ten hours requires burning a pound of coal in a coal-fired electric plant. The electricity use of an average American home results in 18,000 pounds of carbon dioxide a year released into the atmosphere.

* To provide energy, fossil fuel combustion produces 27 billion tons of global-warming carbon dioxide yearly. If solidified it would make a mountain about a mile and a quarter high and a base over 6 miles in circumference.

* The same quantity of energy provided annually by nuclear fuel would produce only 14,000 tons of solid waste. Since that fuel is made from uranium, which is very dense, the volume is small. It would occupy a cube that was about 20 yards on a side—about the size of a big townhouse.

* The comprehensive life cycle of nuclear power emits the same quantity of greenhouse gases as the life cycle of wind power and less than that of solar power.

* The U.S. gets 20% of its electricity from 104 commercial nuclear reactors. Nuclear power accounts for 71% of greenhouse-gas free generation in the U.S. Nuclear power is the single largest displacer of greenhouse gases in the world.

* The UN Intergovernmental Panel on Climate Change has concluded that nuclear power must play a greater role in minimizing greenhouse gases.

* The debate about nuclear power and its role in mitigating greenhouse gas emissions will step up significantly in the near future. The first two applications to build new nuclear plants were filed in September, 2007, with the Nuclear Regulatory Commission. The NRC expects as many as three dozen nuclear plant license applications in the next year or so. Mining companies plan to invest in U.S. uranium mining to meet the increased demand for nuclear fuel, and new prospecting has begun.

Source

16. What about nuclear radiation risk?

People tend not to distinguish high-dose radiation of the kind that killed people in Hiroshima and Nagasaki and firefighters in the Chernobyl reactor from low-dose radiation, which is common in every day life. Concrete a foot thick stops high-dose radiation. You can calculate your own radiation dose by going to http://www.ans.org/pi/resources/dosechart/

* Natural background radiation from rocks, soil, water, and cosmic rays exposes people living in the U.S. to about 300 millirem per year on average (a millirem is a unit by which radiation is measured).

* xray.gifThe highest dose of manmade radiation an American is likely to be exposed to is from therapeutic and diagnostic medical radiation. It saves millions of lives annually. Americans on average now receive as much radiation from medical sources as they do from nature, about 300 millirem.

* One chest X-ray gives a person a dose of 10 millirem.

* Denver.gifResidents of Denver are exposed to 700 millirem per year from natural radiation.

* People moving from the Chernobyl area to Denver would be increasing their level of radiation exposure.

* Residents of the area around Three Mile Island nuclear plant, which had a reactor meltdown in 1979, received on average an exposure of 1 additional millirem. If they had moved to Denver they would have increased their radiation exposure sevenfold.

* Epidemiological surveys of people living in regions of the world with naturally higher natural background radiation do not find that rates of radiation-associated diseases are higher than average jet.gifin these areas.

* Airline pilots and cabin crews who fly regularly between Tokyo and New York receive an average of 900 millirem per year.

* The Columbia University’s Mailman School of Public Health has found that nuclear workers are healthier than comparable groups in other industries. banana.gifSimilarly, nuclear submarine crews are healthier than comparable groups.

* Our food and water contain radioactive substances. Eating one banana exposes a person to 0.01 millirem.

* Living within 50 miles of a nuclear plant exposes a person to an estimated 0.009 additional millirem per year. The National Cancer Institute performed a large survey of people living near nuclear plants and other nuclear facilities and found no increase in radiation-related diseases.

17. What about nuclear waste?

Most of the nuclear waste in the U.S. comes not from nuclear power plants, but rather from the arms race. The biggest environmental cleanup in history has been underway for decades to isolate that waste and to remediate contaminated sites.

* Nuclear warheads and bombs from the Cold War are being converted into fuel. Ten percent of our electricity comes from it.

* Spent nuclear fuel is safely stored in pools and thick concrete cylinders at nuclear plants around the U.S.

* All the spent nuclear fuel from power plants and other sources since the beginning of nuclear power in the US 50 years ago is so small in volume that it could all fit in a single CostCo stacked to a depth of 9 feet. All the spent fuel generated in the annual operation of a single power plant reactor would fit in the bed of a standard pickup truck.

* If an American got all his or her lifetime electricity solely from nuclear power, that person’s total share of the waste would fit into one soda can. Of that, only a trace is long-lived. In France, where nuclear fuel is recycled, waste is drastically reduced, so that the lifetime total for a family of four would fit in a single coffee cup.

* Half of our electricity comes from burning coal. If an American got all his or her electricity from coal over a lifespan of 77 years, that person’s mountain of solid waste would weigh 68.5 tons and would and would fit into six 12-ton railroad cars. That person’s share of carbon dioxide from coal emissions would come to 77 tons.

* The annual solid residues of coal combustion in the U.S. come to 890 pounds per American: enough to fill one million railroad coal cars.

* Coal waste contains hazardous substances: arsenic, mercury, lead, and other toxic heavy metals. But coal waste is exempt from regulations for hazardous waste. It is released into the environment as fly ash or as invisible gases. Coal waste pollutes water tables and the air; it causes acid rain and ocean acidification; it is a major contributor to smog and catastrophic global warming.

* Pollutants from coal-fired plants cause 24,000 premature deaths a year in the U.S. alone and hundreds of thousands of cases of lung and heart disease. In China, coal combustion kills 400,000 a year.

* Coal-fired plants concentrate uranium, thorium, and radium during combustion and therefore emit 100 to 400 times more radiation than nuclear plants. Annually U.S. coal-fired plants concentrate enough uranium-235 to power all of the reactors in the country.

* Worldwide, per terawatt-hours of electricity generated (a terawatt is one trillion watts), nuclear power is responsible for the fewest deaths of all large-scale energy production.

* U.S. deaths from the operation of nuclear power in over 40 years of operation: 0. Deaths from Chernobyl since the accident in 1986: 60. (Most of these fatalities were suffered by emergency workers in the plant.)

* Due to tens of thousands of studies, a great deal is known about how to isolate and shield spent nuclear fuel for the long term. But the likeliest outcome of today’s inventory of spent fuel is that it will be recycled. The small volume of remaining waste can be safely encapsulated in special containers and immobilized in deep geological formations. The U.S., Sweden, and Finland all are working on repositories of this kind.

Source

18. What about nuclear power plant safety and security?

— OR —

WHY A CHERNOBYL CAN NEVER HAPPEN IN THE U.S.

* The Chernobyl reactor accident occurred under worst-case circumstances that involved the worst design, management by political hacks, and lack of a containment building. If the reactor had been contained there wouldn’t have been a dispersal of radioactive material.

* All reactors in the United States, Europe, and Japan are enclosed within multiple barriers of containment. Reactor buildings are made of walls of dense concrete and steel that are 3 to 5 feet thick. The reactor fuel is enclosed in a thick steel pressure vessel. The buildings are negatively pressurized to prevent outflow of any emissions. In 1979 at Three Mile Island, a partial reactor meltdown occurred. Thanks to the reactor vessel and containment building, there was no large-scale release of radioactive material to the environment. Containment buildings are the most robust structures on earth. A plane flying into one would be crushed, although hitting a target that small is virtually impossible.

* In 1988 Sandia National Laboratories in USA performed a test to find out what happens when an aircraft impacts a massive, hardened target. A rocket-propelled F4 Phantom jet (about 27 metric tons, with heavy engines, both close together in the fuselage) rammed into a 12-foot thick slab of concrete at 500 miles per hour. This was part of a study to determine whether a proposed Japanese nuclear power plant could withstand the impact of a heavy aircraft. Most of the collision energy went into the destruction of the aircraft itself - about 96% of the aircraft's kinetic energy went into the its destruction and some penetration of the concrete, while the remaining 4% was dissipated in accelerating the 700-tonne slab. The maximum penetration of the concrete in this experiment was 2 inches.

http://www.break.com/index/concreteplane.html

* American nuclear plants are designed to operate as safely as possible and contain multiple backup systems to make sure the reactor is kept properly cooled.

* Every American nuclear plant is required to have inspectors from the Nuclear Regulatory Commission on site and ready to shut down the reactor at the slightest suggestion of a serious problem.

* Reactor operators must undergo stringent psychological and performance tests and must spend many years in training before being permitted in the control room.

* Just as pilots train on aircraft simulators, reactor operators train for many years on nuclear plant simulators so that they will respond quickly and appropriately to a wide variety of accident scenarios.

* The nuclear power industry is motivated to police plants carefully because the whole industry can be damaged by problems at a single plant.

* American nuclear plants have multiple security barriers. These have been enhanced since 9/11. Access to a nuclear plant is extremely difficult. Heavily-armed guards, jersey barriers, checkpoints, turnstiles, and other security measures are in place. Very few people are permitted near the reactor building or the control room.

* Polls indicate that the majority of people who live around nuclear plants are satisfied that they are safe and do not object to additional nuclear plants being built.

* In 2006, a poll conducted by the Los Angeles Times and Bloomberg about energy and global warming found that most respondents think we must take prompt action. When asked about nuclear power, 61% favored it as a way to reduce greenhouse gases. Among those in the under-thirty age group, support was 71%. Trends in other polls also indicate a growing consensus about the necessity of increased nuclear power.

* Take this questionnaire, Relative Danger of Energy Sources, and see how you score. http://www.quaker.org/fep/reldangersquestions.html

Source

19. Energy Science FAQ - http://www.benwiens.com/energyFAQ.html

20. Oil FAQs

21. How long has PV been around? The photovoltaic effect was first recognized by Edmund Bacquerel, in France, in 1839. Scientists made solar cells of selenium in the 1880s. And, modern PV technologies were developed at Bell Labs and RCA Labs in the mid 1950s.

22. How does electricity get stored for use after sun goes down? There are two options: An RAPS (Remote Access Power System), or a Grid Connect system. Grid Connect systems direct excesss electricity produced during the day back into the local electricity grid. While doing so, it turns your electricity meter backwards. As a result of this, you then receive credit for any power that you put back into the grid. RAPS systems, on the other hand, store energy produced during the day in batteries for use as required.

23. Solar panels in the shade? - The output of any panel will be reduced or cut off if shaded. However, some solar panels do work better than others in the shade. If a single cell is heavily shaded, that cell is cut off.

24. Is Self-installation of Solar System possible? Yes. Using solar system installation kits, the average mechanically inclined homeowner can install a solar system for his home. In order to install a 1 KW solar system, it could take about two days. You will still need an electrician to sign off the final wiring into your main fuse box.

25. How does Solar System connect into current house power? The solar system can be wired into your existing fuse box via a circuit breaker.

26. How much roof space is required to install a solar system? Consider this rule of thumb: A 1.0 KW system will need approximately 10m2, 1.5KW system needs approximately 15m2 and so forth.

27. What will be the approximate weight of Solar System on roof? The system weighs approximately 25 kilograms per square meter.

28. What are inverters and why are they required for solar systems?

An inverter, in the context of renewable energy, is a device that will convert your DC battery voltage into mains type AC power.

Most medium to large scale solar design is to power everything from mains type AC voltages "inverted" from the DC battery bank. The advantage this gives us is that we can purchase conventional appliances from the local electrical store.

29. What is a wind farm?

Wind farms are power plants made up entirely of wind turbines – sometimes one or two, or as many as 100. It’s called a “farm” because they’re usually found in rural areas.

30. Are we running out of natural gas?

No. The United States has adequate natural gas resources - if government permits them to be developed. Through technology that is advancing daily, industry can explore for and develop the nation's gas resources while protecting the environment. In the lower-48 states alone, federal onshore and offshore lands where exploration and production is forbidden, or severely limited, hold an estimated 213 trillion cubic feet of natural gas (a 10-year supply at today's demand rate). It is important that Congress and the Administration address the growing natural gas supply/demand gap today to ensure that this clean-burning fuel is available to Americans at an affordable price. Plentiful supplies of natural gas are critical to a strong, growing U.S. economy, and they are key to U.S. energy supply security - http://www.naturalgasfacts.org/faq/index.html (for the US)

31. Can one geothermal system provide both space heating and cooling for my home? And what about heating hot water?

Yes. A geothermal system can be a combination heating/cooling and hot water heating system. You can change from one mode to another with a simple flick on your indoor thermostat. Using a desuperheater, some geothermal systems can save you up to 50% on your water-heating bill by preheating tank water.

32. How does a geothermal system heat water for my home?

Using what is called a desuperheater, geothermal systems turn waste heat to the task of heating hot water. During the summer, when the system is in cooling mode, hot water is produced free as a byproduct of the thermal process. In winter, with the heating mode, the geothermal system heats a portion of your hot water.

33. How much space does a geothermal system require?

Most of a geothermal system’ installation is underground. Inside the house, the heat pump units are about the same size as a traditional heating and cooling unit.

34. How long will geothermal systems last?

Geothermals are durable and highly reliable. The system contains fewer mechanical components, and all components are either buried in the ground or located inside the home, which protects them from outside conditions. The underground pipes in many cases carry warranties upto 50-years.

35. Do geothermal systems make much noise?

No. Geothermal units are very quiet, providing a pleasant environment inside & outside of the home. They have no noisy fan units.

36. How safe are geothermal systems?

Geothermal systems are safe and protected. With no exposed equipment outdoors, children or pets cannot injure themselves or damage exterior units. They have no open flame, flammable fuel or potentially dangerous fuel storage tanks.

37. Can geothermal systems be used for commercial, industrial, or apartment requirements?

Yes! Many geothermal systems are being installed using a multitude of systems hooked up to many buried vertical or horizontal loops. This simplifies control and internal load balancing.

38. How much does a geothermal system cost?

The initial investment for a system is higher than that of a conventional heating or cooling system. However, when you consider the operating costs of a geothermal heating, cooling, and water heating system, energy savings quickly offset the initial difference in purchase price.

39. What other costs are there besides the geothermal system itself?

You can expect an installation charge for any electrical work, ductwork, water hook-up, and other provisions or adaptations to your home that are required.

40. How difficult is it to install geothermal systems for my house?

Most geothermal units are easy to install, especially when they are replacing another forced-air system - known as a retrofit. Ductwork must be installed in homes without an existing air distribution system.

41. Can I install a ground source heat exchanger myself for my home?

Unless you are a professional in this field, it's not recommended. Thermal fusion of the pipe, drilling and trenching are procedures best handled by licensed professionals. Nonprofessional installations may result in less than optimum performance.

42. Will my existing ductwork function with the installation of a geothermal system?

In most cases, yes. Your dealer or installer will be able to determine ductwork requirements and if any minor modifications are needed.

43. Will an underground loop for the geothermal system affect my lawn or landscape?

No. Research has shown that loops have no adverse effects on grass, trees, or shrubs. Most horizontal installations require trenches about six inches wide. Vertical loops require little space and do not damage lawns significantly.

44. Can a geothermal system be added to my fossil fuel furnace?

Yes. Called dual systems, they can easily be added to existing furnaces for those wishing to have a dual-fuel heating system. Dual-fuel systems use the geothermal system as the main heating source, and a fossil fuel furnace as a supplement.

Web resources used:

http://www.igshpa.okstate.edu/geothermal/faq.htm

http://www1.eere.energy.gov/geothermal/faqs.html

http://www.smart-nrg.com/geofaq.php

http://www.freedomenergysystems.com/Geothermal/GeothermalFAQ.html

http://heatpumpathome.blogspot.com/2007/09/geothermal-heat-pumps-open-loop-systems.html

http://www.greenrock.com.au/targetingGeothermalEnergy/faq.php

http://www.boreal-geothermal.com/geothermal-heat-pumps-faq-what-are-they-and-how-do-they-work.htm

http://www.adamsheatingcooling.com/geothermal_faq.php

http://www.yodergeothermal.com/faq.php

http://www.ieahydro.org/faq.htm

http://www.jhpl.com/hp-faq.htm