Overview
Renewable energy has become the new feature for electricity. Wind turbines and solar panels are at the forefront of such technology, both depending on natural sources to generate power.
Each person could serve as a small source of electricity by simply walking. The sum of a large number of people contributes to electricity by giving it back into a system creating a sort of symbiotic relationship. Green powered shoes will literally provide an energy footprint to produce electricity when in motion with the help of piezoelectric plates placed in special points in and around the insole and sole of the shoes were the pressure is enough to generate power. Subsequently we envisage that the power will be used to transfer electricity accumulated in the battery supply to a given locality by means of a mobile station. An app will also be developed to track the energy source and direct it where it is needed. We believe that this technology will prompt people to walk more in the hopes of getting up to further contribute to their green footprint.
Operations
Firstly, all the required piezoelectric plates are properly fitted in a special solid material in each shoe. According to electrical rules, when anything is connected in series, the voltage decreases and the current remains constant. In the case of a parallel connection, the voltage remains the same, and the current decreases. However, the aforementioned application of piezoelectric plates utilizes a principle that works a little differently from the latter. When all the piezoelectric plates are connected in parallel a variation in voltage and current occurs. This long-time variation for the battery charging directly is not good for battery life; thus in this instance, a bridge rectifier is placed so when the input comes from piezoelectric,c it goes to the rectifier and it converts in proper positive cycle waveform and equivalent power supplied to the battery for the charging. The battery is slowly charged when the stepped output comes from the rectifier. For experimental purposes, we used a 1000mAh, 3.5V battery. Commonly, mobile charging is on 5V. If the battery is not 5V a step-up circuit is used in order to boost the voltage from 3.5V to 5V. Thus, a little voltage drop occurs when the system works from 3.5V to 5V.
Electrical Components:
1. Piezoelectric plates
2. Bridge rectifier
3. 5V or 3.5V rechargeable battery
4. > 5V (any voltage) to 5 V charging USB – 2 way chipset
5. USB charging cable
6. Wireless plate
Shoe applications:
1. Generate electricity for smart clothing technology
2. Sports & fitness (In gym – on treadmills)
3. In places of entertainment
4. Routine walks
5. Long recreational walks and hiking
Other uses:
1. Inside wooden flooring (banks, shopping malls, supermarket)
2. Speed bump/Speed reducers
Charging small devices
There are two ways to charge a mobile phone, either directly from the battery or via 5V chipset circuits. If charging is done directly from the battery, the phone may charge a little slower due to low voltage. If the mobile phone is charged through the 5V chipset circuit the voltage remains stable and charges at a constant speed of 5V. The chip is specially designed for two way power supply. In some circumstances if a user does not want to carry the charger and power bank one can opt to charge the battery in the shoes by normal charger. This is useful for outdoors were one can carry a USB cable and charge the mobile phone, tablet or any USB chargeable device which is operated at 5V. It may also be crucial for hikers who may find themselves in perilous situations. If a GPS is implemented in the shoes the likelihood of retrieval would be greater. The energy may also power clothing with embedded technology.
Energy utility contribution
Utilization on a higher rating by giving power to the energy utility can be achieved through the participation of a large number of people. The following is information from a test explaining how to charge a higher power rated battery and how to transfer stored energy to the utility in exchange for credits, points etc.
For this purpose, a 3000 mah, 5V battery was used in each shoe. Each pair contained two batteries totalling a 6000 mah rating at 5V. The design of the shoes ensures that they are fully surrounded with piezoelectric plates and on in addition, the front portion of the shoes can contain five small solar sheets. Therefore, when the power is generating from the piezoelectric plates and solar cell they both charge together to the battery which can be used for any USB devices, including a USB power outlet to communicate a Wi-Fi dongle and provide a hotspot on various locations, which can be suitable for travel purposes.
The next step is to give back energy to the utility. In this scenario, when the battery is almost fully charged or more than 50% then it is possible to transfer the power. There are two types of designs, which are a removable battery or with cable. So when the user is at the mobile station, which is installed by any local council, government department or private entity on the street, the battery can be removed and placed in the mobile station. There is a special port connection for that special battery, so there is no problem for positive and negative. On the other side there is an option to transfer via cable, which is already installed in the station so the user can take that cable from another side and connect with the battery charging port which is installed in the shoes.
Regarding power purchasing, there are two ways to come about this: One is DC to DC and other is DC to AC. For DC to DC the credit amount is much greater than DC to AC due to some losses in the conversion. For DC to DC the user can go to the mobile station and connect via cable or removable battery to the machine and press a button to start transferring the power. There is a special ID allocated to each pair of shoes which the user has to enter before starting the process. So when a given ID is entered the credit amount will be added to the recipients’ account. With regards to DC to AC, there is a special low consumption power inverter installed at mobile station, which converts from 5V DC to 230V AC via removable battery or cable. The starting process is same in both types. Just a different is the credit which is good in DC to DC. On the other side DC to AC a little bit credit is less because of the conversion of power from DC to AC.
The duration of the process depends on the battery and how much it should be charged. When the power transfer process reaches 90%, the machine will send a signal and automatically halt the process –all batteries have own DOD capacity. The credit received in the account can be used to charge other mobile stations with the use of an ID at no cost or if not used within certain number of days the utility energy company can offer a rebate in the user’s invoice bill.
Wireless
In this scenario we will focus on wireless transfer technology.
This chargeable battery can be used in the above mentioned scenarios. However in this instance we are envisioning a setting to implement this technology to supply energy back to the energy utility company/organisation wirelessly.
On the front part of the shoe will be a round circle while a charging station will also have a round plate to receive the energy generated from walking.
On main streets in major cities one can encounter various wireless charging stations, also known as Wi-Fi energy receivers. Upon charging the shoe batteries the user can go up to that station and place the front part of the shoe with a particular round plate. When the shoes come in contact with the round plate the charged energy is automatically transferred from the shoe energy storage to that station. Generally this energy level is not in AC voltage due to the small amount of storage, thus the transfer will be from DC to DC and the station receives the energy in return transferring credit/s to the users’ account.
The energy transferred can be used in the charging stations similar to kiosks station for the public use. It can also be used as that station provides public Wi-Fi domain, depending on the amount of energy given. In the initial phase when the user gives his/her account number as login and commences the energy transfer the system will automatically calculate, with references, and informs how much Wi-Fi time is available for the user. A time limit can be shown on the given station. Upon pressing start, the Wi-Fi system sends an OTP code to enter in the login page and the user can access free Wi-Fi on mobile or any other devices up to a certain time.
This can be used for signal lights or crossing light operating from battery and solar panel in cases of cloudy weather conditions.
Composition of the shoe
The battery will be placed between the heel and a specially made TPR heel structure. There will also be sufficient air circulation. We are looking at new generation types of batteries which are waterproof, bendable or another option is using a 3D battery. The TPR heel structure will also serve as a foot stabilizer, therefore the foot will always come into exact contact with the piezoelectric plates.
Leave a comment