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The Ground Beneath our Feet

Can you remember the last time the ground gave way beneath you? When you thought the ground was stable, but for some reason it wasn’t? Perhaps you encountered a pothole on the streets of Amsterdam, or you were renovating your house and broke through the floor. Perhaps there was a molehill in a park or garden. You probably had to hold on to something to steady yourself. Perhaps you even slipped or fell. While I sincerely hope that nobody here was hurt in the process, I would like you to keep that feeling in your mind when reading what follows. It is the central theme of the words that will follow. The ground beneath our feet today is not as stable as the streets of Amsterdam, your park around the corner or even a poorly renovated upstairs bedroom. This is because whatever devices we use and whatever pathways we choose, we all live in hybrid physical and digital social spaces (Kitchin and Dodge 2011). Digital social spaces can be social media platforms like Twitter or Facebook, but also chat apps like WhatsApp or Signal. Crucially, social spaces are increasingly hybrid, in which conversations take place across digital spaces (WhatsApp chat group) and physical spaces (meeting friends in a cafe) simultaneously. The ground beneath our feet is not made of concrete or stone or wood but of bits and bytes.

Laadgedrag van PlugIn Hybride Elektrische Voertuigen op publieke laadpunten

Er is regelmatig discussie in Nederland rond het laadgedrag van Plug in Hybride Elektrische Voertuigen (PHEV’s) in vergelijking met full electric voertuigen (FEV’s). Veelal gaat het hierbij om de vraag in hoeverre fors-gesubsidieerde PHEV’s veel elektrisch laden en daadwerkelijk veel elektrische kilometers maken. Een veelgehoorde aanklacht is dat PHEV’s relatief weinig zouden laden, veelal op de verbrandingsmotor rijden en als zodanig onterecht in aanmerking komen voor subsidie. De Hogeschool van Amsterdam (HvA) doet onderzoek voor de vier grote gemeenten (G4: Amsterdam, Den Haag, Rotterdam, Utrecht) en de Metropool Regio Amsterdam (MRA) waarbij laadgedrag op het publieke laadnetwerk wordt geëvalueerd. Sinds 2012 zijn hierbij meer dan 2 miljoen laadsessies geregistreerd op meer dan 6000 laadpunten op het publieke laadnetwerk van de G4 en MRA.

FIRST STEP TO FULL DC-POTENTIAL : IMPROVING ENERGY EFFICIENCY IN HOUSEHOLD EQUIPMENT

Electrification of transportation, communication, working and living continues worldwide. Televisions, telephones, servers are an important part of everyday life. These loads and most sustainable sources as well, have one thing in common: Direct Current. The Dutch research and educational programme ‘DC – road to its full potential’ studies the impact of feeding these appliances from a DC grid. An improvement in energy efficiency is expected, other benefits are unknown and practical considerations are needed to come to a proper comparison with an AC grid. This paper starts with a brief introduction of the programme and its first stages. These stages encompass firstly the commissioning, selection and implementation of a safe and user friendly testing facility, to compare performance of domestic appliances when powered with AC and DC. Secondly, the relationship between the DC-testing facility and existing modeling and simulation assignments is explained. Thirdly, first results are discussed in a broad sense. An improved energy efficiency of 3% to 5% is already demonstrated for domestic appliances. That opens up questions for the performance of a domestic DC system as a whole. The paper then ends with proposed minor changes in the programme and guidelines for future projects. These changes encompass further studying of domestic appliances for product-development purposes, leaving less means for new and costly high-power testing facilities. Possible gains are 1) material and component savings 2) simpler and cheaper exteriors 3) stable and safe in-house infrastructure 4) whilst combined with local sustainable generation. That is the road ahead. 10.1109/DUE.2014.6827758

Data als driver

De Hogeschool van Amsterdam doet al meer dan 10 jaar onderzoek naar het opladen van elektrische auto’s en de benodigde laadinfrastructuur. Een dynamische wereld waarin de ontwikkelingen heel snel zijn gegaan. Het onderzoek van de HvA is meegegroeid met deze wereld. Van AC tot DC en van plug-in hybride tot volledig elektrisch. In dit boek geven we een overzicht van de ontwikkelingen en de onderzoeksprojecten gedurende deze periode.

Wireless Power Transfer for battery Charging

Impact of smart charging for consumers in a real world pilot

A smart charging profile was implemented on 39 public charging stations in Amsterdam on which the current level available for electric vehicle (EV) charging was limited during peak hours on the electricity grid (07:00-08:30 and 17:00-20:00) and was increased during the rest of the day. The impact of this profile was measured on three indicators: average charging power, amount of transferred energy and share of positively and negatively affected sessions. The results are distinguished for different categories of electric vehicles with different charging characteristics (number of phases and maximum current). The results depend heavily on this categorisation and are a realistic measurement of the impact of smart charging under real world conditions. The average charging power increased as a result of the new profile and a reduction in the amount of transferred energy was detected during the evening hours, causing outstanding demand which was solved at an accelerated rate after limitations were lifted. For the whole population, 4% of the sessions were positively affected (charged a larger volume of energy) and 5% were negatively affected. These numbers are dominated by the large share of plug-in hybrid electric vehicles (PHEVs) in Amsterdam which are technically not able to profit from the higher current levels. For new generation electric vehicles, 14% of the sessions were positively affected and the percentage of negatively affected sessions was 5%.