The new combination of solar cells and supercapacitors

By PhD students attending the
Norwegian Research School in Renewable Energy 2014, NORREN

Introduction

The world’s climate is subject to change through the emission of greenhouse gases such as CO2, which has increased rapidly over the past decades. The share of renewable energy sources in the world’s power supply need to increase in order to reduce CO2-emissions and global warming. Many of the renewable energy sources are intermittent sources – meaning that it is not possible to predict when they will produce electricity. For instance the power production of a solar cell depends on the weather conditions. If it is completely cloudy there is not much production, but if the day is a partly clouded one the production rate can vary a lot. This is illustrated by Figure 1 (a), showing the power production of a solar cell on a partly cloudy day. An energy storage system is needed to store energy during excess production, and to deliver energy in times of energy deficit. While lithium-ion and nickel metal hybrid batteries can store large amounts of energy (up to 180 Wh/kg), they fall short during rapid changes in production and load. Supercapacitors can complement the battery in a hybridized energy storage system for solar cells, such as to supply the necessary high power when needed and hence increase the battery lifetime (Glavin et al., 2008), or they can smooth the power output from solar cells such as to reduce the voltage peaks and stabilize the voltage to the grid (Figure 1 (b)). Simulations done by Björn Veit and Thomas Hempel in our group work also proves that supercapacitors works very well in responding to the solar cell power output as shown in Figure 1 (c)).

Figure 1. (a) Power production from a solar cell on a partly cloudy day, (b) power smoothing (red curve) by using supercapacitors, and (c) the simulation scheme using supercapacitors integrated with solar cell module.

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

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. 

Supercapacitors for peak shifting over short durations in PV-systems

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

Introduction

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.

Decentralised mini-grids based on renewable energy - Case Study: Svalbard

Group work, NorRen Summer School, by
Sara Ghaem Sigarchian, PhD candidate at KTH Royal Institute of Technology, Sweden
Chiara Bordin, PhD candidate University of Bologna, Italy
Dr. Gideon Goldwine, Ben-Gurion University, Israel
Fabio Buonsanti, Head of Operations Norway at Aega AS, Norway
Georgios Fytianos, PhD candidate at NTNU, Norway

What we would like to focus on is something that could be considered a bridge between policy and science section, and something that lies on the edge of this summer school and that reflects both our interdisciplinary backgrounds and the interdisciplinary nature of the research institutes to which we belong to.

Svalbard is the vastest and northernmost wild area in Western Europe, that sixty percent of the archipelago is glacier and it is a paradise for rare species of seabirds.

As a country with well-established traditions in environmental and climate research, it was highly surprising to learn about the controversial choice of Norway to encourage a coal enterprise on Svalbard.

Smart Campus project

By participants at the NorRen Summer School 2014
Professor Paul Borza, Professor at Transilvania University of Brasov, Romania
Professor Gady Golan, President at Hermelin Academic College of Engineering, Israel
Kaveri Bhuyan, Researcher at SINTEF, Norway
Vasco Gomes, Researcher at Transylvania University Brasov, Romania
Mohammad Ostadi, PhD candidate at NTNU, Norway, and
Nuno Amaro, PhD candidate at University in Lisbon, Portugal

Smart Grids are the electric grids of the future. 

Although everyone in science and technology knows the term, there is not yet a clear definition for it. To help people understand the methodologies involved, our group decided to create a little example of a smart grid. 

The created project was named Smart Campus. The idea is to establish a micro grid system, operating as an energetic island, in a Smart Grid context. The campus consists of 5 departments/buildings which can be seen as grid users. 

 

The main goals of this project include:

1. Creation of a self-sustained self-managed energy system;
2. To demonstrate a holistic energy efficient system;
3. To generate consumption and tariff patterns for optimization of energy efficiency;
4. Consumer and government education by increasing customer awareness;
5. Dissemination and deployment of the Smart Grid concept;
6. Building a knowledge base of the smart grid consumers behavior;
7. Connecting to the distribution network and other micro grids.

Like any faculty campus, this one is connected to the power grid. However, it will only buy energy from the grid as a last resource, since it has its own power sources. The considered power sources are: solar panels, wind turbines, a micro hydro generator, and a diesel generator. Since one of the main issues in existing electric grids is related to energy storage, this campus will also have a storage system consisting of batteries (for medium term storage) and flywheels acting as fast energy stabilizers to assure the continuity of the electric system in case of a fault.

To measure spent energy and to be able to optimize energy consumption it is necessary to add intelligent devices such as smart meters and smart energy counters. The considered consumers for this scenario are comprised of departments and neighboring micro-grids which are faculties. This brings up the possibility to not only use generated energy in the campus, but also to trade it with neighbors.

Smart Grids – What’s in it for me?

By
Gabriela Pena, Royal Institute of Technology, Sweden
Orna Raviv, University of Haifa, Israel
Ofira Ayalon, University of Haifa, Israel
Peter Hall, University of Sheffield, UK
Rikke Stoud Platou, Norwegian University of Science and Technology, Norway
Shiyu Yan Norwegian school of economics - Norway
Zvi Baum, University of Haifa - Israel

Although there is universally accepted definition of what smart grids will be, they may be broadly regarded as a collection of energy generation, distribution, storage, communication and usage technologies that will allow consumers to flexibly access a wide range of energy services. They will allow greater freedom of energy usage, will allow consumers to become producers and the emergence of new generators plus many other benefits. Above all Smart Grids will allow citizens and communities to play a truly democratic role in the energy market.

Source: http://www.offshorewind.biz/2012/06/21/germany-siemens-tests-smart-grid/

How to light up rural Bangladesh: Renewable energy mini-grid solution for villages

By
Katherine Inzani, PhD student, Department of Materials Science and Engineering, Norwegian University of Science and Technology

Ershad Ullah Khan, PhD student, Department of Energy Technology, KTH Royal Institute of Technology, Sweden
Duong Le, Postdoctoral Researcher, Department of Energy, Politecnico di Milano, Italy​ 
Nhi Nguyen, PhD student, Department of Energy, Politecnico di Milano, Italy
Livingstone Senyonga, PhD student, NMBU School of Economics and Business, Norwegian University of Life Sciences

Bangladesh in 2014: three quarters of rural villages are in darkness with no clean fuel for cooking. Kerosene lanterns and hurricane lamps light up the darkening sky and generate black carbon. People cook their meals by firewood in open traditional stoves. Women and children face dangerous health problems. Business and studies end at dusk. Sustainable access to electricity for the 100 million of the population that are not connected to the national grid is a huge challenge but will give widespread benefits. Here we present a model for electrification of a typical village in Bangladesh, and show that it is feasible, with some initial funding, to utilize local resources for electricity and clean cooking fuel in a sustainable way. This in turn will support social services such as healthcare and schools, and encourage development of local businesses and entrepreneurship.

Mini-grid configuration

Electricity is a pre-requisite for technological development and economic growth of a nation. Around 30% of people in Bangladesh earn below $2 per day. Countries that are lower in per capita energy consumption have low adult literacy rates, life expectancies and education index. In remote areas of Bangladesh especially in the rural and hilly regions, the health, education and communication system are in deteriorating condition because of the unavailability of electricity. In this context, energy deficiency is one of the main barriers to poverty alleviation, industrial and economic advancement, empowerment, and rural development. 

A typical village is Sherpur, located on the bank of the river Jamuna. The village consists of 219 households with an average of five family members. It is unlikely that the village will be connected to the national grid in the next 25 years. The main livelihood is agriculture and the lifestyle is simple, not requiring large amounts of electricity for dramatic improvement. Electricity for lighting, cooling, TV, radio and IT alone would bring enormous benefits, facilitating better learning conditions in schools, with longer study hours and PC-based learning made possible, as well as benefiting business and improving communication and healthcare. TV, lighting and productive uses in community centers enhances social life and may foster community based development. Risk of fire from kerosene lamps and candles would be significantly reduced. Energy security would no longer be related to the availability of diesel and kerosene.

Energy resources from a hybrid system

The electricity and cooking fuel needs of the village can be provided by a hybrid system of photovoltaics, an anaerobic biomass digester and a small-scale gas engine.
 

Solar PV systems utilize semiconductor-based materials (solar cells) which directly convert solar energy into electricity. Solar PV systems have many attractive features, including modularity, no fuel requirements, zero emissions, no noise and no need for national grid connection.

In a biomass digester, agricultural residues (biomass) are converted into a combustible gas in a high temperature digester, and the gas is cleaned to remove tars and particulates before being stored in a large tank. From the storage tank, clean gas is partly provided through a piping network to the individual households in the village for cooking using gas stoves. Reduced deforestation, health benefits and hygiene improvement through waste disposal are considerable benefits of using the anaerobic digester. This gas is also provided to an internal combustion engine-generator to generate electricity along with the PV solar.

Energigjenvinning av avløpsvann

Av Tor Haakon Bakken, PhD-student ved CEDREN

Anslag fra NVE, Vestlandsforskning, SSB antyder at 10-20 % av energiforbruket i en vanlig norsk husholdning går til oppvarming av vann i varmtvannsbereder, og ytterligere energi går til oppvarming av vann i vaskemaskin, oppvaskmaskin og i forbindelse med matlaging. Det totale energiforbruket til oppvarming av vann kan anslagsvis være 25 % av det totale energiforbruket (som regel elektrisitet) og internasjonale anslag ligger prosentvis enda høyere. Det aller meste av dette vannet sendes rett i sluket og ut på det kommunale avløpsnettet med mye gjenværende energi (i form av varme).

Ideen går ut på å ta vare på denne varmen i avløpsvannet og bruke denne til ny oppvarming av rent vann, evt. til oppvarming av rom i hus. Ideen er å utvikle et system som automatisk skiller varmt fra kaldt vann i avløpssystemet i huset, dvs. før vannet slippes ut på stikkledning og ‘tappe’ energien i det varme vannet gjennom (for eksempel til oppvarming av varmtvannsbereder eller rom) før det avkjølte vannet slippes tilbake til avløpsledningen og ut sammen med det kalde vannet. En realisering av ideen kan være å installere en sensor høyt opp i de av rørene som frakter varmt og kaldt vann for å detektere temperaturen i vannet. Når vannet holder en temperatur som er høyere enn en bestemt grenseverdi ledes vannet inn i et eget rør hvor vannet midlertidig sluses inn i et separat system hvor varmen i vannet tappes. Energien i det varme vannet kan for eksempel brukes til å varme opp varmtvannsbereder. Den kan benyttes en varmeveksler, være direkte kontakt mellom varme/kalde overflater eller lignende. Når vannet er tappet for varme ledes vannet tilbake til avløpsledningen der det kalde vannet renner ut av huset og ute i gata sammen med det andre avløpsvannet. Varme gjenvinnes dermed internt i huset før det slippes ut sammen med annet avløpsvann/gråvann. 

Det later til å være flere mer eller mindre ferdige tekniske konsepter som kan anvendes til dette, og min vurdering er at det er ikke behov for krevende teknisk utvikling for å realisere konseptet. Det finnes blant annet piloter i Hamburg, det er gjort forskning i Nederland og Husbanken har faktisk beskrevet et konsept som virker mer eller mindre klar til anvendelse, med noen forskjeller fra hva jeg tenker. 

I en innovasjonssammenheng er det imidlertid interessant å spørre seg hvorfor dette ikke i større grad er tatt i bruk og det er kanskje der arbeidet burde gå videre. Spørsmål som bør stilles er hvorvidt det er økonomiske eller institusjonelle barrierer som stenger for anvendelsen. Er rammevilkårene gode nok, eller ville en subsidiering på lik linje med den støttet ny el-produksjon (ref. grønne sertifikater) får gjøre at varmegjenvinning vil "av seg selv" og komme i anvendelse? Finnes det en leverandørindustri som er klar? Slike spørsmål bør besvares for å berede grunnen for «det neste store ENØK-tiltak i norske boliger».

Tor Haakon Bakken

Vi i Morpho Solar er en spinoff-bedrift fra NTNU sin entreprenørskole som utvikler innovative varmelagre for solkjøkken. Teknologien vi har muliggjør lagring av solvarme i flere timer.

Solkjøkken er nytt i Norge, men er allerede kjent i USA og en rekke land i Asia og Afrika. Solkjøkken er en slags blanding av en utegrill og et stormkjøkken, men varmen kommer direkte fra solen. Solstråler blir konsentrert ved hjelp av speil, og varmen kan brukes direkte til matlaging. Vi utvikler et termisk varmelager som stabiliserer solkjøkken og gjør det mulig å også bruke solkjøkken på kvelden og når det skyer over.