Tremendous Capacitors for Atmanirbhar and Swachh Bharat

Photo voltaic Photovoltaic power is obtainable all through the day whereas the Solar shines. Nevertheless, this power is extremely fluctuating in nature. Additionally, lighting is especially required throughout evening when photo voltaic power shouldn’t be accessible. Due to this fact, there’s a want for power storage units. The plain selection is Lithium-ion battery. Regardless that Li-ion battery is the best choice, there are some limitations:

1. Value of Li-ion Battery is growing yr after yr. Therefore, these batteries will likely be primarily used for automobiles and mobiles. For stationary functions we have now to search out alternate options.

2. Li-ion Batteries can deal with few thousand cost/discharge cycles. This means the battery must be changed after about 5 years

3. Re-cycling of Li-ion batteries is difficult and costly.

4. India doesn’t have Lithium mines. We’re fully depending on imports. Therefore it turns into essential to discover different units for power storage.

5. Li-ion Batteries additionally use different metals equivalent to Nickle and Cobalt and so forth. Due to this fact, these batteries are usually not atmosphere pleasant. Lot of mining is required to get these metals.

Proposed Different

Right here we are going to discover use of Supercapacitors for power storage for low energy however widespread functions. Supercapacitors (or Extremely Capacitors) are additionally known as as Electrical Double-Layer Capacitors. They use porous carbon electrodes and retailer power within the type of electrical area. Not like batteries which retailer power in electrochemical type. These supply very massive values of capacitance, measured in Farads. Typical working voltage of those capacitors is low (2.7 V). Following are their benefits:

1. Will be charged and discharged 100,000 occasions with out dropping storage capability. Therefore, they’ve lengthy lifetime of > 15 years.

2. Quick charging and discharging

3. Safer than batteries

4. Use simply accessible uncooked supplies (eg carbon), therefore atmosphere pleasant. No dependency on imports for costly uncooked supplies.

5. Straightforward to recycle

Limitations:

1. Low particular power and decrease working voltage

2. Linear discharge voltage

3. Barely greater self-discharge

4. Larger price. A 500 F capacitor presently prices about Rs 400 and 100 F capacitor prices about 175 rupees.

As of immediately, the price of supercapacitors is considerably greater. Only for storing few Watt-Hours of power we have now to make use of a number of capacitors. Therefore the price of even small low energy techniques is pretty excessive. Some recommendations are given beneath for lowering the fee:

• Mass Manufacturing: As mentioned earlier, supercapacitors don’t want costly uncooked materials. So, the excessive price may be primarily attributed to low volumes of manufacturing. Due to this fact, there’s a must determine many functions which might generate large demand. Because the manufacturing scales up, robotically the manufacturing price will come down.

• Redesign for sluggish cost/ discharge functions: Most supercapacitors accessible out there are designed for dealing with excessive (in amps) cost/ discharge currents. Due to this fact, these Supercapacitors have thick terminals and huge electrodes. Nevertheless, in small photo voltaic functions the capacitor cost/ discharge currents are low (in milliamps). Therefore, for such functions capacitor design may be optimized to cut back price and measurement.

• Larger worth of capacitance for a given measurement and value: By optimizing capacitor design for decrease present functions, it could be attainable to get greater capacitance in the identical measurement and value. It will enhance the power storage capability for given measurement and value.

• A lot of the Supercapacitors accessible out there are imported. Stimulating the demand will appeal to Indian corporations for native manufacture. The price of domestically produced capacitors will likely be a lot decrease.

• Authorities Subsidy to the producers: Corporations who wish to manufacture supercapacitors, our authorities ought to present some monetary help for establishing manufacturing strains and for getting the most recent design know the way from established producers.

Supercapacitor based mostly Clock:

This is among the finest suited functions. Wall clocks want very low energy. Wall clocks use one AA major battery per yr. Each home has few such clocks. So, we’re consuming enormous variety of batteries yearly containing hazardous chemical substances. Additional, these batteries are usually not correctly disposed, therefore pose large risk to the atmosphere and well being. Right here, clock energy provide design is proposed which makes use of photo voltaic power and Supercapacitors. The goal right here is to run the clock nonstop for at the very least 15 years beneath all climate circumstances. It will eradicate using 15 AA cells and scale back hazardous chemical waste.

Design particulars:

Determine 1 reveals the circuit diagram of proposed energy provide. It consists of two small photo voltaic panels PV1 and PV2. Following are the specs of those panels:

• Voltage at most energy = Vmp = 5 V (Relies upon upon daylight depth)
• Present at most energy = Imp = 100 mA
• Open circuit voltage = Voc = 6 V
• Measurement = 70 mm X 70 mm

These panels are related in parallel utilizing two diodes D1 and D2 (1N5819). These Schottky diodes block present from one panel getting into the opposite panel. The panel output voltage Vpv is fed to the Supercapacitor C1 (100F 2.7V) by way of present limiting resistor R1 (330Ω 1W). Voltage regulator IC1 (TL431) is related throughout C1. It regulates the capacitor voltage to 2.5 V. IC1 ensures that the capacitor voltage by no means exceeds rated voltage of two.7 V. Observe that, diodes D1 and D2 additionally cease C1 from discharging into the panels, when there isn’t any daylight.

The output of capacitor C1 is related to the clock terminals by way of present limiting resistor R2 (220Ω). Throughout these terminals three diodes D2, D3 and D4 (1N4007) are related in sequence.

Complete Ahead voltage of D2, D3, D4 = 0.65 X 3 = 1.95 V

The clock motion operates within the vary from 2 V all the way down to 1V. Thus, the three diodes restrict the voltage Vclock to lower than 2V. C2 is used to cut back voltage dip at any time when the motion attracts pulse present. Fig 2 reveals the assembled PCB.

The working of the above circuit will likely be clearer after varied waveforms proven in Figs 3, 4 and 5.

Determine 3 reveals capacitor voltage (C1) and +Vclock voltage. These waveforms had been captured with out mounting the filter capacitor C2. Additionally, worth of resistor R2 was modified to 100Ω. As seen within the determine, the capacitor voltage is steady at 1.99 V. We see dip in +Vclock voltage each second when the clock motion attracts pulse present. Utilizing math operate of the oscilloscope, hint M (purple) has been plotted which provides distinction between Ch1 and Ch2. This waveform is the voltage throughout R2. Determine 4 reveals the identical waveform expanded.

From the purple hint of Fig 4 we will calculate present by way of R2.

• Regular present by way of R2 and D3, D4, D5 = 0.2 V/ 100Ω = 2 mA
• Common pulse present = 0.6V / 100Ω = 6 mA
• Precise pulse present drawn by the clock motion = 6 – 2 = 4 mA
• Pulse length = 30 msec
• Common present drawn by clock motion = 4 mA * 30 msec / 1000 msec = 0.12 mA.
• Common Energy drawn by the clock motion = 0.12 * 1.71 = 0.2 mW
• Power Consumed throughout 24 hours = 0.2 mW * 24 = 4.8 mWh
• Power saved within the capacitor = 0.5 * C1 * V * V = 0.5 * 100 * 1.99 * 1.99 = 198 joules
• Power saved = (198 / 3600) * 1000 = 55 mWh

From above calculations it’s seen that, we have now nearly 11 occasions power accessible within the capacitors on per day foundation (beneath very best circumstances). Nevertheless, there are self-discharge loss within the capacitor and losses in R2 and Diodes and residual voltage within the capacitor. Contemplating all of the losses we will safely assume that the saved energy within the capacitor will likely be ample for about 2 or 3 days. This issue helps in continuous working of clock on wet days when the daylight may be very much less.

Determine 5 reveals the filtered voltage waveform +Vclock. With C2 (4700 µF) related on the output, the heart beat peak voltage drops to lower than 200 mV. Additionally, the worth of resistance has been elevated to 220Ω to cut back present by way of the diodes. These waveforms had been captured when the C1 voltage was 1.08 V. Thus, it’s clear that the clock works all the way down to 1 V.

Interface:

Determine 6 reveals proposed AA measurement dummy cell made out of plastic materials. It has metallic +ve and -ve terminals. Two wires are related to those terminals and introduced out by way of the holes offered. These wires are related to +Vclock and -Vclock. Consumer can merely insert this dummy cell within the clock second.

Utilization of the system:

Wall clocks are mounted contained in the buildings therefore they don’t obtain direct daylight. Due to this fact, two PV panels have been used in order that the circuit works on the subtle ambient gentle accessible contained in the rooms. There isn’t any must mount the panels within the direct daylight. The panels could possibly be mounted on the identical wall on which the clock is current. We have now to make sure that all through the day, the panels get good ambient gentle. If this gentle shouldn’t be ample then we will mount the panels close to the home windows the place gentle depth is greater. Two PV panels additionally make sure that throughout wet season the circuit works correctly. {Photograph} of built-in system is proven in Fig. 7.

Fig.7 {Photograph} of system displaying PV panels and clock interconnections.

Costing:

Assuming one cell is required per yr, in 15 years of lifespan, we spend about 150 rupees on these cells.

The price of proposed system is given beneath:

• Supercapacitor 100 F 2.7 V Rs 175
• Two 6V PV panels Rs 110
• PCB and small parts Rs 35
• Complete Rs 320

Observe: These costs are for MOQ of fifty items. For one or two portions costs could also be a lot greater.

Thus, we see that the price of proposed circuit is nearly double as in contrast with the cash we spend on batteries. We have now to think about few extra factors relating to price comparability that are as follows:

1. The lifetime of PV panels is 30 years. Therefore, we have now to think about solely half of it’s price. As it may be reused for an additional 15 years together with one other clock.

2. As of immediately, the manufacturing quantity of supercapacitors is low, therefore its price is greater. If the manufacturing quantity will increase by many folds the fee will come down considerably.

3. Through the use of the proposed circuit, we’re eliminating the battery hazardous waste which in any other case goes into landfill. This poses risk to atmosphere and well being. We have now to issue this atmosphere price in favor of the proposed design.

4. Supercapacitors don’t require imported materials. It largely makes use of carbon; therefore it can present power independence for our nation.

5. Use of proposed circuit additionally eliminates the trouble of changing the batteries. This can be a major benefit for corporates, as they will scale back the manpower and wish for conserving inventory of batteries.

Optimization:

If there may be some place contained in the room, the place direct daylight is obtainable for few hours then it could be attainable to take away one PV panel. With direct daylight, single panel can totally cost the capacitor shortly. It will assist in lowering the fee to some extent. It will want long run testing in all seasons to make sure nonstop operation.

Energy provide design for a number of clocks

In lots of corporations there are a number of clocks mounted on the identical wall. These clocks are used to indicate native time from totally different international locations. Additionally, in wall clock showrooms, retailers and restore retailers there are a number of clocks working on particular person batteries. Due to this fact, massive variety of cells are consumed in these retailers. For such functions a single energy provide is designed which might cater to many clocks. On this case, the price of the circuit will get divided amongst all of the clocks and the general price of the circuit comes down.

Circuit design for 5 clocks:

Determine 8 reveals the circuit diagram of energy provide which caters to 5 clocks.

This design consists of two varieties of models. One storage unit and 5 filter models for 5 clocks. A 6V 3W photo voltaic PV panel is related to the storage unit. Storage unit consists of a 500 F capacitor which is charged by way of diode D10 (1N5819) and resistor R10 (68 Ω 2W). Regulator IC10 (TL431) clamps the capacitor voltage to 2.5V. This regulator is rated for 100 mA present. Therefore, further Zener diodes DZ1 and DZ2 (2.5V 1W) are related in parallel with the IC10. These Zener diodes can deal with extra present.

Filter Models 1 to five must be mounted very close to to their respective clocks. The filter unit consists of filter capacitor of 4700 µF (C11 to C15, one for every filter unit). Additionally, every filter unit has three 1N4007 diodes related in sequence (D11 to D25). The outputs of 5 filter models are related to 5 totally different clocks.

The PV panel is mounted on a roof prime or in a spot the place there may be good sunshine. The storage unit is positioned in a location contained in the constructing, the place the cable from PV panel comes contained in the constructing. From storage unit, by way of present limiting resistors R11 to R15 skinny cables are related to the respective filter models. These wire lengths could possibly be few tens of ft lengthy. The capacitor within the filter unit will compensate for the cable inductance. In Fig 8, purple wires join R11 to filter unit 1. Equally, blue wires join R15 to filter unit 5.

Costing:

Costing for this design is given beneath:

• Supercapacitor 500 F 2.7 V Rs 400
• 6V 3W PV panel Rs 400
• PCB and small parts Rs 200
• Complete Rs 1000

The fee per clock is 1000 / 5 = 200 rupees. Thus, we will say that a number of clock design will present higher price benefit. Thus, it may be carried out by all store keepers in order that demand for supercapacitors will get a lift.

Conclusion

Above design demonstrates use of supercapacitors for storing small quantity of power. As crores of clocks are getting used, it presents large potential for lowering using chemical batteries. It will assist in lowering hazardous waste. Additionally, it can generate demand for crores of supercapacitors. Many fold enhance in manufacturing quantity of those capacitors will carry down the fee. It would open up many different areas the place these capacitors could possibly be used for power storage. Cut back dependence on imported Lithium and different expensive metals. Every home will generate small quantity of solar energy and it’s cumulative impact will likely be vital. Want of the hour is to determine many extra such functions.

Supercapacitors can contribute in direction of making Atmanirbhar and Swachh Bharat.