Energy

Thursday, November 4, 2010

Scientists answer Guardian readers' toughest energy questions

Nine of the world's top energy scientists answer your questions on topics from peak oil to nuclear fusion

• See the questions other readers have submitted

Photo: eioc.pnl.gov

• Adam Vaughan
• guardian.co.uk, Wednesday 3 November 2010 13.38 GMT
• Article history 
Last week we asked you to put your toughest energy questions to nine world-leading energy scientists. You responded with more than 350 serious and searching questions on everything from renewable energy to nuclear power. Here are 10 of the best questions, answered by the awards committee of nine scientists on the Global Energy prize.

1. Could we support our current western lifestyle with only "renewable" energy? Asked by Jim Burks

José Goldemberg answers: Presently "renewable" energy accounts for approximately 10% of the energy consumed in Europe. The impressive growth of energy produce from windmills, biomass and other renewables indicates that renewables as a whole could account for "circa" 50% of all energy consumed by 2050. The present western lifestyle requires the energy equivalent of three tonnes of petroleum per year. Improving the efficiency of energy use (with more efficient automobiles, refrigerators and other end-use appliances as well as better home insulation) could reduce that amount by at least 30%. As is well known considerable efficiency gains have already been achieved in the OECD countries since 1973. Present energy consumption would be 50% higher than it is actually without them. That reduction could give renewables a better chance to replace fossil fuels.

2. Do you agree with the US Joint Forces Command (JFC) that spare capacity in global oil production may very well disappear in 2012 and a shortfall of 10m barrels per day develop by 2015? NoSurrenderMonkey (and others)

Clement Bowman: The word 'may' in the question, and the multiple use of the word "could" in the energy summary statement of the US JFC document, obliges one to accept the possibility that "yes it could". However, I believe that it is highly unlikely that there will be significant oil shortages over the next few decades. Once there is a perceived gap, forces come into play that cause the gap to be filled. Here are some of the likely forces. Even modest increases in oil prices will convert unproven resources into recoverable reserves. Action on energy efficiency has finally taken hold in response to the need to reduce carbon dioxide emissions. New pipelines are under construction or planned in North America that will bring crude oil to refineries that have unused capacity. The enormous quantities of shale gas that have been discovered will provide part of the energy mix. The Canadian oil sands are just starting to ramp up with new more environmentally acceptable insitu recovery technology. China and India will use a combination of more efficient coal technology, nuclear energy and renewables to help meet their accelerating demand for energy. When I entered the oil industry in the 1960s, the conventional wisdom was that there was only 10 years of oil supply left. Predictions have a habit of failing.

3. The world's population is due to rise to 9 billion people. Can the planet supply the energy needed to achieve that end? ken brookes

Tom Blees: Widespread predictions that energy demand will double by mid-century to meet the needs of an expected 9-10 billion humans are, I believe, too conservative. Billions of people rely on now-shrinking glaciers for much of their water supply, with many areas of the world already lacking adequate water. Increasing human numbers by 50% means that we will have to provide most of the water for some billions of people primarily with desalination, an energy-intensive process. Add to that the fact that the majority of people in the world today use a fraction of the energy used by those in developed countries, and one could easily anticipate at least a tripling of demand in developing countries as they strive strive to improve their standard of living. In the book Prescription for the Planet, I explained how a doubling of energy supply could easily be accomplished by 2050 at a rate of deployment even less ambitious than the French employed as they converted to nuclear power in the 1970s and 80s. Given the ability to factory-produce fast reactors of the type described here, a concerted global effort to meet mid-century energy demands should be quite within reach. The fuel is already available and - for all intents and purposes - virtually free.

4. I'm 25 years old. What's your best case scenario for the world's energy supply mix when I'm 75? What's your worst case scenario? And where you you think we'll actually be? Ian Bullock

Tom Blees: While there's widespread agreement that fossil fuels must eventually be abandoned, there seems to be no consensus on which technologies can be expected to take their place. The contenders already available run the gamut from some of the most diffuse energy sources (wind, sunlight) to the most energy-dense. While nearly all of the latter systems currently in use consist of light-water nuclear reactors, fast reactors can extract well over 100 times more energy from uranium, and are seen by most nuclear prognosticators as being the inevitable successors to light-water reactors and the solution to the looming global energy crisis. All of the energy a person in a developed country today can be expected to use in a lifetime - for electricity, transportation, heating and cooling, and the energy that goes into producing all that they will consume - could be supplied by a single piece of depleted uranium the size of half a ping-pong ball. Despite all the controversy over competing technologies today, this amazing fact - plus the fact that it can supply all that energy safely and without harm to the environment - should eventually carry the day, leaving other energy sources as bit players on the world stage.

5. Is energy storage - ie battery technology - one of the biggest things holding back renewables and widespread energy efficiency? Look at the intermittancy of wind power, the requirements of a "smart grid city", electric cards etc - surely decent energy storage could transform the economics of these industries. And when might/how the problem be solved? Mago Salas (and others)

Alvin Trivelpiece: An excellent source of technical information regarding batteries is the Wikipedia site. Even so, it does not answer the implicit theme of the question. Namely, why not large-scale energy storage in batteries to capture energy from intermittent sources such as wind or solar for use at times when the energy is required by a consumer? The use of batteries for energy storage is a matter of the application and its need for a source of energy. Standard small batteries for toys and other convenience devices such as flashlights are examples where the cost per kilowatt-hour is irrelevant. The consumer pays the asking price and discards them without additional cost. Some solar applications using battery storage make great sense. Remote applications in the middle of desert where the cost of transmission lines is greater than the cost of a solar panel with some battery storage system. Same reasoning applies for spacecraft applications. For other applications, the three laws of thermodynamics and the rules of economics must be taken into account. A simplified version of thermodynamics is: (1) You can't win, (2) You can't even break even, and (3) You can't get out of the game. This means that you have to take all costs from cradle to grave into account and see if you make money selling the energy at competitive price. If you can do this without any subsidy, then you don't have a sustainable situation. Unfortunately, when this is done for batteries, with all factors taken into account, it doesn't seem to come out favorably. That is, taking into account the cost of the raw materials including whatever environmental remediation might be needed, the transport of these materials to the location where fabrication takes place, cost of fabrication and distribution, the cost of disposing of the batteries, including the cost of maintenance during their useful life, etc. Any energy storage or distribution scheme that doesn't make net energy, without subsidies, is not likely to be sustainable. Subsidies are a good way to get some products developed and deployed, but at some point it is usually assumed that the subsidy can eventually be eliminated, or justified on some non-economic basis. 

See more: http://www.guardian.co.uk/environment/2010/nov/03/scientists-answer-energy-questions     
Posted by Jasmina Nikoloska

 

Wednesday, October 6, 2010

Human waste turned into renewable gas to power homes

Pilot project is first in UK to produce domestic gas from sewage

• Food waste to provide green gas for carbon-conscious consumers

Next time you flush the toilet, you could be doing your bit for green energy. After being stored for 18 days, human waste will from today be returning to homes in the form of renewable gas.

Centrica is opening a plant at Didcot sewage works which will be the first in the UK to produce renewable gas for households to use.

Photo: treehugger.com

National Grid believes that at least 15% of all gas consumed could be made from sewage slurry, old sandwiches and other food thrown away by supermarkets, as well as organic waste created by businesses such as breweries.

However, there are fears in the industry that the government's spending cuts could make it more difficult for companies to come up with the £10bn needed to develop the new plants and pipelines.

Because it is more expensive to produce renewable gas, companies say they need to be paid twice the market rate for it to make economic sense.

But a proposed subsidy, scheduled to come into force in April, has yet to be approved and there is speculation that the government could delay or scrap it.

The Didcot facility is a pilot project to demonstrate the technology and will supply about 200 homes with gas. The project is a joint venture between Thames Water, British Gas and Scotia Gas Networks.

One industry expert likened the process to a "cow's stomach on a life support machine". The sewage sludge is collected in air-tight vats which are heated and enzymes added to speed the anaerobic digestion process and break down the material. Methane is produced and then it is purified ready for use.

See more: http://www.guardian.co.uk/business/2010/oct/05/human-waste-turned-renewable-gas 

Posted by Jasmina Nikoloska

Friday, September 24, 2010

The Energy Diet

Trimming your energy use is a lot like taking off extra pounds. You’ve heard all the advice, but the thought of starting a diet can be daunting. Will you feel deprived? Can you stick to all the changes you’ll need to make? And where do you begin? The Energy Diet aims to help you take a step-by-step approach toward a lifestyle that is healthier for the planet, and may end up saving you money.

http://environment.nationalgeographic.com/environment/energy/great-energy-challenge/energy-diet/

Adapted from Dutch language book, The Ideal Energy Weight, by Klaas van Alphen, a researcher at Copernicus Institute for Sustainable Development, Utrecht University and Herman van der Meyden, a Shell engineer who has participated in the company’s future scenarios project.

Posted by Jasmina Nikoloska

Friday, September 17, 2010

Could shale gas become a new energy source for Britain’s energy needs?
  

Following on the US trend of exploiting shale gas, UK company Cuadrilla Resources is establishing itself as a European pioneer in introducing shale gas drilling techniques, in a field near Blackpool in Lancashire.

Channel 4 News reports from 26 July 2010 showed that soon the company will start drilling more than 3 kilometres below the surface in rocks known as the Bowland shale, which extends from Pendle Hill near Preston to the Irish Sea, to extract natural gas that is trapped there.

Representatives of Cuadrilla Resources are confident that Bowland shale is the right place to start drilling; their only concern is whether natural gas can be found in quantities large enough to make their efforts worthwhile.

Photo: renewable-energy-news.info
Shale gas is nothing uncommon for the energy industry; it is the actual methodology and techniques for its extraction and use that are new. A US engineer, George Mitchell, developed the current technique, known as “hydraulic fracturing”.

To access shale gas, drilling must be downwards into the gas-bearing rock more than 3 kilometres below the surface, and then horizontally for thousands of metres more with a mixture of water, chemicals and sand being pumped in under high pressure to fracture the rock.

The water opens up cracks in the rock in which the sand grains then lodge, keeping them open and creating space for the gas to travel up and be collected at the surface. While shale gas extraction in Britain is still a young practice, the technique has already revolutionised US energy market.

Some estimations shows that shale gas – together with other “unconventional” gas resources like methane from coal seams – have the potential to produce more than 5.66 quadrillion cubic metres (2 quadrillion cubic feet) of gas, enough to meet America’s gas needs for the next 100 years, Channel 4 News reported.


See more: http://www.energetika.net/eu/novice/co2-emissions/could-shale-gas-become-a-new-energy-source-for-britains-ener

Posted by Jasmina Nikoloska