By Bruno De Wachter / Published on Wed, 2010-07-07 05:30
American scientists capture lost energy
The solar energy falling onto the earth is incredibly abundant, but the majority gets lost anyway. So what is the big deal about improving the efficiency of solar cells? Well, for starters, highly efficient PV cells could create a complete sea change on the cost, material use, and the amount of land presently employed in harvesting the sun’s energy.
Today, the efficiency limit of photovoltaic cells is approximately 30 percent. For a long time, this was thought to be a physical border, as certain high-energy photons in sunlight exceed the band-gap energy in a PV cell. That energy, in the form of so-called 'hot electrons', is too high to be turned into usable electricity and is lost as heat in conventional solar cells.
Well, it seems we had better start referring to that physical border in the past tense. The 'hot electrons' could not be captured — until now.
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By Bruno De Wachter / Published on Wed, 2010-05-19 05:30
Side effects turned into advantages
History is full of stories of men feverishly searching for the magic trick that will solve all of our energy problems. Those quests have generally been whistled back by the laws of physics. These laws are what they are and we have to cope with them; our energy future will not be built by revolutionary solutions plucked out of the blue.
Perhaps the most intelligent solutions are not those that try to breech the limits of nature, but those that make maximal use of what nature has on offer. These are the stories of side effects turned into advantages, resulting in efficient combined techniques.
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By Bruno De Wachter / Published on Tue, 2010-02-16 14:58
The IEP roadmap to 2050
In December 2009, the International Electricity Partnership (IEP) published its 'Roadmap for a Low-Carbon Power Sector by 2050'. The IEP was created in October 2008 at an international summit of electricity chief executives held in Atlanta, USA. Its roadmap focuses on Australia, Canada, the European Union, Japan, and the United States.
The IEP industry leaders see a crucial role for the electrical power sector. Historically, electrical power has been the largest source of CO2 emissions, the main contributor to climate change. But in the upcoming decades electricity can become a key lever in evolving towards a low carbon economy, states the IEP. The key technological evolutions necessary to make this happen are the electrification of heating and transport, and carbon-free power generation.
Aggressive application of technology
The report sets a target of 60% to 80% reduction in carbon emission by 2050. According to the Intergovernmental Panel on Climate Change (IPCC) this is the level of reductions required to stabilise greenhouse gas emissions in the atmosphere at 450 to 550 ppm CO2eq. This is estimated to correspond with an average global temperature rise of 2-3 °C. The IEP argues that reaching this target is only possible through an aggressive application of technology. It advocates policies that provide incentives for high investments in renewable energy, Carbon Capture and Storage (CCS), nuclear power, smart grids, electric vehicles, heat pumps, and energy efficiency.
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By Bruno De Wachter / Published on Tue, 2009-09-22 05:30
Thinking out of the box
Surfing the Internet, one frequently comes upon articles on new inventions for harvesting energy and solving the energy problem. Last week, we reported on the concept of 'solar highways'. That idea is certainly not the craziest one to come along...
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By Bruno De Wachter / Published on Tue, 2009-09-15 05:30
Integrating road networks and power networks
The US Department of Transportation has awarded funding for building a 'solar highway' prototype. A solar highway contains photovoltaic (PV) modules covered with bulletproof glass as a road surface. The surface also contains a grid of LEDs that can light the roadway, draw lines, and flash warnings that react to traffic sensors. Apart from supplying power for the LEDs and sensors, the energy generated by the PV modules will also be used to heat the highway when required. The remaining energy can be used for houses and businesses alongside the road. If this systems works as projected, it could well make power stations and power lines superfluous. According to an article on Matter Network, covering all American roads with this system would produce an annual yield of energy three times as large as the entire U.S. energy consumption in 2006.
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By HDK / Published on Tue, 2009-08-25 11:09
This paper analyses the effect of the novel market-based instrument of emission trading on investment strategies of local utilities in the climate friendly technologies of combined heat and power (CHP) and renewable energy resources (RES). We take the example of the German electricity sector, where the economic conditions have been subject to dramatic changes in recent years.
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By Bruno De Wachter / Published on Tue, 2009-08-18 05:30
A concept often causing confusion
The 'smart grid' is commonly presented as an indispensable part of the future power system. It is claimed that a true liberalised electricity market with a high penetration of distributed generation will only be able to supply a high degree of power reliability if grids are made smart.
But what exactly is a 'smart grid'? Reading through some literature on the subject, one quickly discovers that it can mean many different things to many different people, often leading discussions to end in confusion.
A smart grid is neither a clearly defined single concept nor a single technology. Rather it is like a basket containing various combinations of balls. The context and the interpretation depend upon the user. Carnegie Mellon University recently published an article describing all of the various balls typically found in this metaphorical basket. Some of them represent innovations that are still in the development phase, while others stand for technologies which have already been applied for years.
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By Bruno De Wachter / Published on Tue, 2009-08-11 05:30
A criterion for expressing the development phase of a new technology
Ever since climate change emerged as a major issue, news reports on innovative sustainable energy technologies have reached a flood level. What those reports mostly do not mention is the particular stage of development of those innovations at the moment of writing. It is generally a long reach between innovation and market introduction, and this path is marked by several development phases, each of which presents particular barriers.
To assess the maturity of evolving technologies, NASA developed a new standard: the Technology Readiness Level or TRL. This standard divides the evolution between the first basic technology research and market introduction into nine levels.
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By Bruno De Wachter / Published on Wed, 2009-07-01 05:30
Leviathan Energy presents a new design concept
While concentrated solar power is entering the commercialisation phase, 'concentrated wind power' is still in the area of bold claims intended to attract research money.
The idea of concentrated wind power is to build a structure that conducts the wind towards the turbine blades and in this way harvests more power.
Recently, an article on CleanTechnica presented a new design of this kind created by Leviathan Energy. It consists of a screen around the base of the turbine that changes air circulation. The company claims this passive structure can increase the turbine efficiency from 30% to as much as 150% at low wind speeds (0-6 meters per second).
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By Bruno De Wachter / Published on Thu, 2009-06-18 05:30
Incremental changes can result in substantial cost reductions
The technologies for producing electricity from solar thermal energy can be divided into three main categories:
- Parabolic trough and Fresnel systems
- Central receiver systems, including the solar updraft tower
- Parabolic dish systems, usually combined with a Stirling heat engine
The first commercial CSP plant, which was built in California in the 1980s, used the parabolic trough concept. It has a total capacity of 354 MW. For many years, this was the only large scale CSP plant in the world. Elsewhere, only small demonstration plants were built, as the high investment cost hampered further deployment.
In 2006, a new commercial 1 MW parabolic trough CSP plant was built in Tucson, Arizona. Since then, the development of CSP as a commercial electricity generating technology has taken off. Many CSP projects are currently being built, the majority of which are in Spain and the USA. It is very likely that because of this market boom, investment costs for CSP will go down. The question is how much and how quickly.
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By Bruno De Wachter / Published on Tue, 2009-06-16 05:30
Diversification complicates price predictions
In regards to PV energy, we will focus on grid connected systems only, since they represent the large majority of the market. The cost of a grid connected PV system is composed of the PV module cost and the 'BOS' cost (Balance of System). The BOS consists of the structures for mounting the PV modules and of the power-conditioning equipment that converts the DC power of the modules into the AC grid power.
Prediction not straightforward
Three difficulties arise when trying to predict the future cost development of PV energy starting from existing experience curves.
- The cost decrease over the past four decades was not at all linear. It alternated periods of sharp decline with periods in which it stayed more or less constant. As a result, experience cost curves that do not represent large time spans can result in a distorted perspective.
- Various PV technologies exist and are difficult to represent with a single experience curve. New types of PV systems may break through in the near future that completely change the average cost of PV modules.
- Even if the future cost of individual PV modules can be predicted, this does not mean the cost of electricity generated by those PV systems can be easily determined. Factors such as geographical location, local support mechanisms, and the size of systems will have a major influence on the average PV electricity cost.
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By Bruno De Wachter / Published on Tue, 2009-05-19 05:30
Electronic management system controls temperature
Last March, the Société de Véhicules Electriques (SVE) presented its new battery system for electric vehicles (EVs).
SVE is a joint venture of the Dassault Group and the Heuliez Company. Dassault is known for the design and manufacture of military and civilian aerospace equipment. Heuliez is specialised in car design, engineering, and OEM manufacturing. The mission of SVE is the development of electric and plug-in electric hybrid vehicles, EV drives, and equipment.
The new system combines the Cleanbat modular battery set, containing one or more lithium-ion units with a capacity of 7 kWh, with the Digital Vehicle Management System (DVMS) control unit. The DVMS controls the charging, discharging, and temperature of each battery unit and the battery system as a whole for optimal performance and safety.
Temperature control is one of the key issues in a battery-powered electric vehicle drive system. If the battery cells become too cold, the autonomy of the vehicle drops. If they become too hot, the battery thermal controls may fail, creating a safety problem. Moreover, both too much cold and too much heat have a negative influence on the life expectancy of the system.
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By Bruno De Wachter / Published on Thu, 2008-12-04 06:30
The top three challenges in this list are related to energy
What are the grand challenges that await engineering solutions in the century ahead? How can engineers put knowledge into practice to ensure sustainability, health, safety and quality of life for the generations to come?
The U.S. National Academy of Engineering (NAE) assembled a diverse panel of experts from around the world to answer these questions. The members are some of the most accomplished engineers and scientists of their generation. They proposed fourteen 'challenges for engineering' that they consider both achievable and sustainable.
It is significant that the first three challenges mentioned in the report are all related to energy. This focus is immediately apparent in the report’s Introduction: 'The Earth is a planet of finite resources, and its growing population currently consumes them at a rate that cannot be sustained. Widely reported warnings have emphasised the need to develop new sources of energy, at the same time as preventing or reversing the degradation of the environment.' The expert panel saw three main engineering challenges that could satisfy this need:
- making solar energy with energy storage economical;
- providing energy from nuclear fusion;
- developing carbon sequestration methods.
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By Bruno De Wachter / Published on Thu, 2008-11-13 06:30
$4 billion investment required
Ocean power is still a minor in the renewable energy sector. It consists mainly of wave power and tidal stream power, and both technologies have only just embarked on their first commercial projects. Today, less than 10 MW of ocean power capacity has been installed. However, according to a report by Greentech Media and the Prometheus Institute for Sustainable Development, this technology could reach 1 GW of installed capacity and grid parity within six years from now.
Such progression would require $2 billion of investment in research, design and development and another $2 billion in commercial production and installation. Compare those figures with the $500 million investment made between 2001 and 2007.
How this technology will develop in the next few years depends greatly on the investment climate and the willingness of the power sector to buy in to these type of projects. These, in turn, depend on the readiness of governments to create dedicated policies and incentives for this sector.
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By Bruno De Wachter / Published on Thu, 2008-09-11 05:30
1.2 MW plant installed off the coast of Northern Ireland
A new type of renewable energy has been connected to the European grid: tidal energy turbines. The SeaGen Tidal System has been installed in the Strangford Narrows, about 400 metres off the coast of Northern Ireland, by Marine Current Turbines Ltd (MCT). The installation was completed last April and the generators were successfully connected to the grid on 17th July. It produces 1.2 MW of power, operating 18 to 20 hours a day. The total manufacturing and installation cost was nearly £10 million.
Like a wind turbine, but more predictable
The Seagen Tidal System consists of a fixed structure bearing two 16m diameter axial flow rotors, each connected to a generator via a gearbox. In contrast with other existing tidal power plants — such as the one on the Rance in France — this system does not require a barrage closing in an estuary. It is sited offshore on a large piling.
The technology is similar in many respects to a wind turbine. However, its principle advantage compared to most other renewable sources is that tidal energy is entirely predictable. In addition, its visual impact is much smaller since it is almost entirely submerged. The slow rotation speed (10 to 15 revolutions per minute) is unlikely to pose a threat to either fish or marine mammals.
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By Bruno De Wachter / Published on Thu, 2008-07-24 05:30
Where is the catch?
Arthur C. Clarke’s famous paraphrase of J. G. Ballard 'that any sufficiently advanced technology is indistinguishable from magic' seems to gain in strength every day. So much that we are all — even the most sophisticated or sceptical of us — ready to accept almost any 'new advance of science' as fact without serious questioning.
Sometimes technology does indeed appear to be close to magic. The Japanese company Genepax claims to have constructed an eco-friendly car that runs on nothing but water. The press agency Reuters walked into the trap with open eyes and published their promotion video.
'It almost sounds too good to be true', says the British commentator on the video. Of course it is too good to be true. Can you find the catch?
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By Bruno De Wachter / Published on Thu, 2008-07-03 05:30
Improving technology, expansion offshore, and exploring the building sector potential
The wind sector has been growing spectacularly over the past decade. However, to sustain these impressive growth figures over the next twenty years in Europe and North America, business-as-usual will not be enough. In several European countries, the number of remaining onshore sites for building new wind farms is already declining (see interview with François and Benoît Henriet, 'Barriers for wind projects', on this blog). Maintaining current growth will require going off-hore, or at least off the beaten track.
- Some offshore wind farms are already in operation, but there is still huge potential — if the technology can overcome some of its current teething problems (see blog post 'How fast can we move?').
- Further expansion of the onshore potential is possible by scaling up existing wind farms in both size and efficiency; radical new design proposals are being put forward.
- Building-integrated wind turbines have both advocates and sceptics in regards to their potential to open up a completely new market.
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By Angelo Baggini / Published on Sun, 2008-06-01 09:00
Year: 2006
Policy Status: In force
On 25th April 2006, France announced a series of public-private research partnerships, including three to reduce dependence on petroleum products and mitigate climate change.
Projects slated to receive substantial public funding from the Agency for Industrial Innovation (AII), included:
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By Bruno De Wachter / Published on Thu, 2008-05-22 05:30
Electric drives for ships and planes
Trains are increasingly electrified, electric motorbikes are booming in Asia, and the all-electric car might be close to mass production. Some people are openly suggesting that water and air transport could become electrically powered as well, completing the move to an 'all electric society'. What are the chances of this vision becoming a reality? Ships with electric propulsion systems already existed at the beginning of the 20th century and are currently ready for a (limited) revival. However, development in powering large aircraft by electric propulsion is much less in evidence.
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