Introduction

Our creative minds started working, elaborating different ideas that we will discuss and combine together.

We challenged ourselves to meet, as accurately as we could, the design criteria and basing our knowledge according to our past research, creating some insightful and sustainable ideas !

Take a look at them!

Design Concept - ZIHANG

Residential Area Energy Supply Scheme

Building solar EV charging station in Singapore faces both challenges and benefits.

For one thing, because Singapore’s close-to-equator location, the sunlight intensity spread evenly throughout the year, which is hugely beneficial for solar power generating electricity. On the other hand, because Singapore’s high population density, available land also suitable for building solar power station is very limited, especially in central Singapore.

My idea is to put PV cell panels in public parking space in non-central area, people charge their car in where they live, or possibly, where they work.

As I mentioned earlier, the limited space in central area makes it very hard for charging station requires large spaces to implement. Singapore’s constant high solar elevation angle during the day throughout entire year, meaning the sun is always above our head during the day, provides a good ground for providing above-car PV cells in open air parking lot.

From Singapore insolation statistics provided by NREL, it can be calculated that 1m2 of PV cell can provide an average of 0.814 to 1.044 kWh of electricity1 (regardless of loss when saving electricity into battery). One of electric car with highest market share, Nissan Leaf, for example, requires 24kWh for a full charge of its battery, which is about the electricity generated by a 30m2 large PV cell. Assuming for a residential area where 300 families reside, 20% family owns a electric car, which requires charging every week. It can be calculated a minimum of 255m2 of PV cell, which is approximately a square panel with side length of 16m. The size is about suitable for 8 cars to park.

download.php?file=489203&embedded=1&text

1. Based on average insolation range from 4.02 kWh/day/m2 to 5.22 kWh/day/m2, energy conversion efficiency of 20%. 

Design Concept - GIDON

Part of our challenge is to find a way of using renewable energy to fuel charging stations for the e-vehicles. I felt that the most sensible option had to be solar energy for a couple of reasons. Firstly, the large scale upon which we are looking to use this renewable energy in Singapore means that we would like to shy away from anything too ambitious or risky. Solar panels are already a widespread method of energy generation; most countries in the world are actually using them in some way or another. Secondly, and more specifically to our country, Singapore is fairly close to the equator, and the sun is shining all year round, so the availability of solar energy is higher in Singapore than in most places in the world.
The idea would be to have charging stations located all around Singapore, fitted with solar panels, so that the solar energy can be channeled and used to charge the cars' batteries.One challenge facing the widespread use of electric cars is the inconvenience of having to wait for the batteries charge; a process that can take several hours. An idea I had was to fit the car with removable battery, so that instead of docking at a charging station for hours on end, users can simply remove their battery, hand it in to the charging station and receive a second, fully charged battery in return.Instead of: download.php?file=488017&view=103777&embwe have: download.php?file=488019&view=103777&emb One of the disadvantages of using removable batteries is that it makes the car design more complex, and is likely to push the price up. It is more straightforward to build an electric car with a battery that stays in the car, than to design one than can be taken in and out.Also, if one is swapping his car battery, it goes without saying that the new battery has to be compatible with his car. You imagine that, just as almost every model of mobile phone has a differently shaped battery, the same is likely to be true about cars, and so charging stations would need to stock a broad range of batteries, which may be expensive and complicated. Perhaps this could be resolved by selling each model with two batteries, one to be in the car and one to hand in to the charging station, in a way that in fact every person charges their own battery in the charging station and never has to worry about finding a battery that is compatible with his car.A third challenge is the liability of constantly removing and reinserting batteries into the car. Apart from the physical exertion that this task demands, it also engenders a certain amount of risk. The constant manhandling of the battery means there is high chance it will get either damaged or misplaced.In summary, the benefit of using a removable battery is that it helps to circumvent the inconvenience of having the car out of use during the charging time. Having said that, we are met with challenges in a variety of areas when applying this system, including car design, the liability created, and the need for a broad range of batteries to be made available.

Design Concept - ZICHUAN

The basic structure of the parking and charging system is shown below. The area of the parking lot may vary between different location because of the land price and the demand of customers. Generally, one charging column is able to serve two cars at a time and drivers can select the charging method (7 hours or 1 hour) by pressing the button on the column. Cables are used to connect charging column with generators.

download.php?file=474921&embedded=1&text

Figure 1. The structure of parking+charging system.

download.php?file=482029&embedded=1&text

Figure 2. The layout of solar PV cell (King and Wettergren. 2011).

In terms of power, I plan to combine solar power and fuel cell. The solar collection board might be placed on the roof of parking lot (if it is not in the open air), or next to it. The average solar radiance in Singapore is stable and the temperature is high, so solar cell is more suitable for Singapore compared to European countries (King and Wettergren. 2011). Since there is no sun light in the evening, fuel cell is an alternative approach to generate electricity for charging. Although the efficiency of fuel cell (45-50%) is much higher than solar cell(maximum 30.3%) (King and Wettergren. 2011), the cost of storing and forming hydrogen is relatively high which might be a heavy burden for Singapore government (Jervis .2015). Besides, hydrogen is not stable, burning impure hydrogen will cause explosion. In order to reduce the risk and cost of using fuel cell, it should be considered as an alternative instead of the first choice.

download.php?file=481993&embedded=1&text

Figure 2. The weekly average solar irradiance in Singapore (King and Wettergren. 2011).

Finally, the location should also be taken into account. The map below shows the planned location of parking and charging system. The area with black circle symbolizes that charging stations have already been built there and the area with red circle means the planned position. As is shown in the map, most charging stations are concentrated in the south part of Singapore. Although the south part of Singapore is more modern compared to other part, it might be better to increase the coverage of electric car charging station in Singapore so that drivers do not have to worry about the low-battery problem. Therefore, a network of parking and charging system is needed to meet the demand of people living in the other part Singapore.

download.php?file=475159&embedded=1&text

Figure 3. The designed charging station network in Singapore.

 

Reference list:

King, S. and Wettergren, P. (2011) ‘Feasibility study of renewable energy in Singapore’, KTH industrial engineering and management.

Jervis, R. (2015) Fuel Cell (lecture to BEng Year 1), UCell. University College London. 20 October.

 

Design Concept - CHIARA

ENERGY SUPPLY SYSTEM

Basically I tried to layout the whole system of the use of EV. 

  1. Starting from the main and abundant resource of Singapore: SUN
  2. Transforming the heat into electric energy through solar panels placed on the roofs of buildings (as Singapore does not have a lot of free surface available)
  3. Connect the charging stations to the solar panels. These charging stations should have the option of super fast charging (in 20 min half the battery charged but the lithium degenerates faster i.e. shorter lifetime) or slow charging facilities.
  4. Recharge the EV and drive for 480km, enough to cross the island (719km² surface) from one end to the other. Without ANY CO2 EMISSIONS !

Design Concept - CHIARA

SINGAPORE ISLAND LOGISTICS

As we discussed in the workshop, one of the main failures of the implementation of EV is the reduced accessibility and frequency of charging facilities. Thus I decided to look at the map of Singapore and allocate different types of charging station:

Especially in Northern and more 'rural' areas:

  • Every 50km on highways → Super Fast charging points
  • Within residential areas (to allow charging while home) → Slow charge facilities (better for EV battery)

In Southern, concentrated area:

  • Introduce EV CAR SHARING facilities to reduce the overall amount of car circulating (taking into account also the problem of traffic and the connected security issues.

Updated on October 21, 2016 at 6:31 PM; 641 page visits from October 15, 2015 at 12:30 PM to September 16, 2024 at 11:51 PM