mandag 27. oktober 2014

Hydrogen Cell Cars and Electric Cars

By Hammad Majeed, NTNU [writer], Usman (NTNU), Lizhen (NTNU), Shahla Gondal, NTNU, Naveed Asif, NTNU, and Idan Liebes
at NorRen summer school 2014

Energy plays a key role in world economy. International energy agency (IEA, 2010a) believes that, if the policies and plans by various governments with respect to energy usage will be implemented than the world primary energy demands will increase by 36% in between 2010 and 2035.

Transportation plays a vital role in carbon dioxide (CO2) emissions, as 33 % of the energy demands come from this sector (Eurostat, 2011).  In order to reduce CO2 emissions and to meet the challenge a strategy for energy efficiency plus renewable energy along with CCS should be implemented. Hydrogen and electric vehicles are one of the key points towards clean environment and to accomplish energy demands.

Social Aspects of Hydrogen Cell vs Electric Cars

This blog doesn’t deals with technical evaluation of these cars instead it depicts people thinking about these technologies. An online survey with in Norway was done along with person to person interaction in Asker city center (Norway) in order to extract information on realistic basis to understand what are the future potential of these technologies, how people will adopt it in to their daily lives, how much they want to spend on these types of cars, whether they have knowhow about these technologies are not.
Total of 86 people were asked about their opinions in the form of questionnaire. The results are explained in graphical method as;

Figure 1: People profile on the basis of gender and age and No. of cars they own

tirsdag 21. oktober 2014

Li-ion Batteries: On the verge of electrification of the car traffic

Group work at NorRen Summer School 2014
By Ahmet Oguz Tezel et al.

Given the rising concerns about the green-house-gas evolution and global warming, the shift from coal power to renewable energy production systems, such as wind and solar, and the shift from internal combustion engines (ICE) to electric vehicles (EV) should be considered necessity (Figure 1). Realization of these transitions, perhaps not widely known by public, relies on the development of advance energy storage systems. Li-ion batteries, which store the energy by mean of electrochemical activity, represent the forefront technology that responds to the demand on energy storage systems. Although receives competition from fuel cells, particularly in relation to EV applications, Li-ion batteries are predicted to dominate the market in the near future since fuel cells are not mature enough a technology and subject to further improvements to go with.

The battery technology has been continuously developed over the last decades, nearing to meeting the technological and practical requirements, although many challenges are yet to be overcome. In this project, we aim at evaluating the feasibility of the application of state of the art Li-ion batteries to EVs, exclusively to cars as the principle mode of passenger transport, by their practical performances in meeting the public needs. We prefer to avoid evaluating the car use as a whole and instead choose to speak in terms of its divisions ( i.e. CO2/km, driving range/day and average speed ). This approach enables us to identify the prevailing mode of car use and suggest a battery solution to the point. 

onsdag 8. oktober 2014

Supercapacitors for peak shifting over short durations in PV-systems

Xuemei Cheng, Wesley Dose, Thomas Hempel, Øyvind Storesund Hetland, Kine Solbakken and Björn Veit at NorRen Summer School 2014


In recent years there has been a growing emphasis on harnessing energy from renewable sources. Photovoltaic (PV) cells have demonstrated great potential as a cheap and reliable source of clean, renewable energy, and PV production facilities are now being deployed at a high pace globally. The output from a PV production system naturally varies with the cycles of the sun (e.g., day and night), requiring other sources of energy to be available when sunlight is scarce or absent. There is another, less well known, issue in PV systems however: the variability of PV output even while the sun shining, due to second- and minute- resolution disturbances in the light absorbed by the solar panel. These fluctuations are usually due to clouds, but any moving object that occludes the path of sunlight will contribute. As more and more small scale PV systems are connected to the local grid, these fluctuations may prove a problem through grid voltage instabilities and temporary grid overproduction due to sharp local peaks in production. A possible remedy to these issues could be to somehow store energy when the system experiences a short spike in production, and then release this energy again when a drop in production occurs. This process would result in a smoother output from the PV system, with no, or minimal, loss in overall production.

How could we implement such an ‘energy buffer’ in a real-life application? The most common alternatives are batteries and capacitors. A battery can offer a high energy capacity (Wh) but low power (acceptance/delivery time, W), while the capacitor offers very high power, but can only store a small amount of energy. Another device has recently joined the market however: the electrochemical capacitor (also known as supercapacitors or ultracapacitors). The supercapacitor fills the intermediate region between batteries and capacitors. It could be considered as a high-capacity capacitor, and it shows considerable promise in storing seconds worth of energy from PV output, even from larger PV systems, while also providing the high rate energy storage/release required.