Journal No.3 – Four dimensions of Power

Tesla vs Edison 

 

Figure 1 – Nikola Tesla, the man behind Alternating Current (AC) (Dattopadhye, 2023)

 

Nikola Tesla and Thomas Edison played a major role in shaping the electricity we use today. Both were pioneers in electrical engineering but their rivalry over Alternating Current (AC) and Direct Current (DC) became one of the most significant technological battles in history.[i]

This conflict, known as the War of Currents, determined the future of power distribution. 

Edison was a strong advocate of DC power, which flows in a single direction and was the foundation of early electrical grids.[ii] DC was reliable for short distances and could efficiently power small electrical networks. However, it had a major limitation; it couldn’t be easily converted to different voltages, making long-distance transmission inefficient. Because of this, DC power stations had to be placed every few miles, making it expensive and impractical for large-scale systems. (Cole & Chandler, 2019)gr

Tesla, on the other hand, introduced AC power, which periodically reverses direction and allows voltage to be increased or decreased using a transformer. This made AC far more efficient for long-distance transmission and allowed electricity to be sent across entire cities and regions with minimal energy loss. (NIDEC Motor Corporation , 2024)

Tesla’s vision of a nationwide electrical grid eventually became a reality. Tesla initially worked under Edison but left after a financial dispute. He later partnered with George Westinghouse, who recognize AC’s potential. Together, they developed AC generators and transformers, making electricity more practical and cost-effective for widespread use. (D'Alto, 2002)

Edison fought hard to discredit Tesla’s AC System. He launched a smear campaign to convince the public that AC was dangerous, even electrocuting animals in public demonstrations to instil fear. He was also involved in the creation of the electric chair, hoping to associate AC with deadly consequences. Despite these efforts, Tesla and Westinghouse proved AC’s superiority. (Cole & Chandler, 2019)

Tesla and Westinghouse won the contract to power the 1893 Chicago World Fair, a huge milestone for AC technology. Then, in 1895, they built the first major hydroelectric power plant at Niagara Falls, successfully providing electricity to Buffalo, New York. This event marked the ultimate victory of AC over DC. (Richard F.Mould, 2017)

Tesla’s AC System became the foundation of modern electricity distribution, powering homes, industries, and cities worldwide. While AC won the war of the currents, DC still has its uses today, especially in batteries, electronics, and renewable energy system. 

Tesla’s achievements represent the power of knowledge and innovation. While Edison focused on protecting his business interests, Tesla relied on scientific advancements to push technology forward. Tesla didn’t just challenge the existing system; he completely transformed how electricity is generated and distributed. At the end of the day, their rivalry wasn’t just about personal conflict, it shaped the modern world. It also proved that true progress comes from knowledge and vision, not just money or business strategies. 

 

 

References

 

Cole, B. M., & Chandler, D. (2019). A Model of Competitive Impression Management: Edison versus Westinghouse in the War of the Currents. (JSTOR, Ed.) Administrative science quarterly, 64(4), 1020-1063.

D'Alto, N. (2002, February ). Edison, Tesla, and the battle of the currents: should electricity be AC or DC? (Odyssey, Ed.) 11(2), 20. doi:https://go.gale.com/ps/i.do?p=ITOF&u=murdoch&id=GALE%7CA83241721&v=2.1&it=r&aty=shibboleth

Dattopadhye, S. (2023). Samirsinh Dattopadhye Official Blog. Retrieved from sadguruaniruddhabapu.com: https://sadguruaniruddhabapu.com/post/wireless-electricity-part-1

NIDEC Motor Corporation . (2024). Retrieved from nidec.com : https://acim.nidec.com/en/drives/control-techniques/News-And-Media/Blog/Drive-Basics/Articles/2016/07/27/A-Brief-History-Of-AC-DC-Electricity

Richard F.Mould, M. P. (2017). Nikola Tesla (1856–1943). Scientist & inventor. Nowotwory. Journal of Oncology, 67(3), 223. doi:10.5603/NJO.2017.0036

 

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[i] AC is Alternating Current while DC is Direct Current 

 

[ii] Electrical Grid is the electricity network that delivers electricity from producers to consumers.

Journal No.2 - Sustainability

Journal No.2 – Sustainability 

Battery Energy Storage System (BESS)  

To mitigate the global calls for the reduction of CO2 emissions gives rise to renewable energy sources. This gives rise to the use of Battery as a one of the solutions to minimise, albeit eliminate CO2 emissions. 

But the question is, does battery energy solution sustainable? 

 

Figure 1 – Synergy’s Kwinana Big Battery Energy Storage System

The phase closure of coal power plant has significantly brought about the influx of renewable energy to be developed for net-zero emission, thus bringing battery energy storage into the fold. 

Currently, Kwinana Battery Energy Storage 1 and 2 are underway and truly helps to the stability of electricity supply to homeowners of Western Australia; for a specific given time, at least 4-6 hours of the day, and needs to be recharge again for peak hours use. (Synergy, KBESS1, 2022) (Synergy, KBESS2, 2024)

Battery Energy Storage system life cycle is around 10 to 15 years and dependent on how it is being utilised. One single cycle per day describes the repeated discharging and recharging process. Cycle life is a measure of how many cycles a battery can deliver over its useful life. (Chapter II-2-B - Batteries in PV Systems, 2018)

The Collie Battery Energy Storage is currently under construction and expected for operational use sometime November 2025, and shall deliver about 64% of energy to WA homeowner. (Synergy, CBESS, 2024)

Both Kwinana Battery Energy Storage Solution 1 / 2 and Collie Battery Energy Storage Solution costs at least around $ 2.8 Billion AUD. 

Currently, there are no immediate plan or strategies on how to properly dispose of spent Big Battery. 

Lithium-ion batteries are classed as dangerous goods and are toxic if incorrectly disposed of. (Commission, 2023) Improper disposal of Lithium-ion batteries in household waste or recycling bins poses risks to people, property, and the environment, including fire hazards during waste procession. Mitigating these risks requires adequate disposal and recycling options, supported by viable facilities, sufficient infrastructure, and access to insurance to handle the growing volume of batteries. (Commission, 2023)

The lack of standardization at the pack and cell level, along with the complexity of storing, transporting, and handling of end-of-life (EoL) batteries, increases costs and reduces recycling incentives. (Thompson, 2020)

Battery Energy Storage Solution is a great innovation to mitigate CO2 emission and towards a net-zero CO2 but aside from developing these Technology, a proper waste disposal and eco-friendly end-of-life disposal are needed to have a more sustainable system. Without proper disposal, one would think that if battery is a sustainable development we need moving forward. Or should we look into Nuclear Energy? 

References

Chapter II-2-B - Batteries in PV Systems. (2018). In D. Spiers, & S. A. Kalogirou (Ed.), McEvoy's Handbook of Photovoltaics (Third Edition) (pp. 798-843). Academic Press. doi:https://doi.org/10.1016/B978-0-12-809921-6.00021-5

Commission, A. C. (2023). Lithium-ion batteries and consumer product safety. Lithium-ion batteries and consumer product safety, 2.

Synergy. (2022). KBESS1. Retrieved from KBESS1: https://www.synergy.net.au/Our-energy/SynergyRED/Large-Scale-Battery-Energy-Storage-Systems/Kwinana-Battery-Energy-Storage-System-1

Synergy. (2024). CBESS. doi:https://www.synergy.net.au/Our-energy/SynergyRED/Large-Scale-Battery-Energy-Storage-Systems/Collie-Battery-Energy-Storage-System

Synergy. (2024). KBESS2. Retrieved from KBESS2: https://www.synergy.net.au/Our-energy/SynergyRED/Large-Scale-Battery-Energy-Storage-Systems/Kwinana-Battery-Energy-Storage-System-2

Thompson, D. L. (2020, October 20). The importance of design in lithium ion battery recycling - a critical review. Green Chemistry : An International Journal and Green Chemistry Resource, 22. doi:https://doi.org/10.1039/D0GC02745F

Energy Crisis - The future is here

Figure 1 – Duck Curve (Synergy, n.d.)

The global energy crisis has underscored the urgent need for sustainable energy solutions. Renewable technologies, including solar, wind, hydro, and battery storage, are being deployed worldwide to mitigate CO2 emissions. While these innovations are promising, they are not yet capable of delivering a full reliable, round-the-clock energy supply. (Uhlmann, 2024)

Currently, renewable energy systems depend on favourable environmental conditions, such as sunlight and wind, which can fluctuate. This intermittency necessitates the continued reliance on conventional power plants to meet energy demands during periods of low renewable output and to charge the battery storage systems. Although advancements in battery technology are progressing, they remain reliant on conventional energy sources for backup and optimal functionality. (Uhlmann, 2024)

The phased closure of coal-fired power plants marks a significant step toward reducing greenhouse gas emissions. However, this transition has contributed to rising electricity costs for households. While initiatives like increased government subsidies provide some relief, they do not fully address the financial burden on consumers. (Energy.gov.au, 2024)

Renewable energy technologies are rapidly evolving but remain incomplete in their ability to meet the full spectrum of energy needs. A hybrid approach, integrating renewables with traditional power plants, is currently essential to ensure a stable and consistent electrical supply.  

Gas generators are crucial for maintaining reliability in a net-zero power system. They provide essential flexibility in wind and solar output, especially during morning and evening peak demand periods. With the closure of coal power plant, Gas generators plays a crucial role in maintaining electricity supply, especially when solar and wind energy are unavailable, particularly during winter. They are also essential for charging battery storage systems. Unfortunately, other than coal power plants, Gas Generators are the only available conventional plants there is, that can carry the weight of shutting down coal power plants. While Gas Generators are not a long-term solution in net-zero emissions, it can be used as transitional technology while we build more renewable energy infrastructure.

There were studies to blend hydrogen to natural gas to minimize CO2 emission of Gas Generators, but the infrastructure is still not available and further feasibility studies are required. The shift to Hydrogen powered Generators is a welcome treat to achieve net-zero but the technology is still under development and on trials. The market for hydrogen powered generator is not yet popular due to high risk of hydrogen storage and producing “green” hydrogen (from renewable source) is energy-intensive and expensive. (Briault, 2021 ) 

Nuclear Power Plant is viable due to its low carbon emissions and energy reliability, however, the challenges of upfront costs, waste management, and public acceptance must be addressed. Also, development of Nuclear Power Plant would take at least 10 to 15 years, and shutting down coal power plant will make Gas Generators more viable in the meantime. 

It is perplexing that Australia, despite being one of the top five natural gas producers globally, is now seeing its eastern states preparing to import gas to meet domestic demand. (Mercer, 2024)

In conclusion, while the shift toward renewable energy is an exciting and necessary development, substantial work remains to fully unlock its potential. The goal is to achieve a sustainable, cost-effective, and reliable energy system that meets the demands of households and industries alike, thus saving our environment for our children’s future. 

With the fast-phased transition to renewable energy, I wonder if we really aim to achieve net-zero or is it all just for business profit. 

References

Briault, T. (2021 , November ). Arup . Retrieved from www.arup.com : https://www.arup.com/insights/when-will-hydrogen-become-a-cost-competitive-industry/#:~:text=Current%20estimates%20show%20blue%20hydrogen,decade%20for%20this%20to%20occur.

Energy.gov.au. (2024). Energy BIll Relief Fund 2024-2025. Retrieved from Energy.gov.au: https://www.energy.gov.au/energy-bill-relief-fund

Mercer, J. N. (2024, September 5). Once unthinkable, gas giant Australia is set to import supplies for the first time. Retrieved from abc.net.au: https://www.abc.net.au/news/2024-09-05/gas-giant-australia-prepares-to-import-gas-as-shortage-looms/104303824

Synergy. (n.d.). Synergy . Retrieved from Synergy Website : https://www.synergy.net.au/Blog/2021/10/Everything-you-need-to-know-about-the-Duck-Curve

Uhlmann, C. (2024, November). SkyNews Australia. Retrieved from youtube: https://www.youtube.com/watch?v=YbxpieEQ7bc&t=1055s

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[1] ChatGPT used for English Structure improvement. 

 

Heat Rate

Measuring the heat rate of a power plant is essential for evaluating its efficiency, performance, and overall economic viability. 

1.) Assessing Efficiency 

• Heat Rate measure the amount of fuel (kJ or BTU) required to generate one kilowatt-hour(kWh) of electricity.

• A lower heat rate indicates higher fuel efficiency – meaning the plant is using less fuel to produce electricity. This is a critical factor in determining how well a power plant converts fuel energy into electrical energy. 

2.) Optimizing Fuel Consumption 

• Fuel is one of the largest operational costs in power plants, especially those running on fossil fuels like coal, natural gas, or oil. 

• By monitoring the heat rate, plant operators can identify opportunities to optimize fuel consumption and reduce operating costs. 

3.) Performance Monitoring 

• Regularly tracking the heat rate allows operators to detect performance degradation over time. 

• A rising heat rate might indicate issues like equipment wear, fouling, or inefficiencies (a failing turbine or cooling system) 

• A stable or decreasing heat rate suggests that the plant is running optimally. 

• This helps to schedule maintenance and avoid unplanned downtimes.

4.) Environmental Impact

• Lower heat rates lead to reduced fuel consumption, which translates into lower emissions (such as CO2). 

• Measuring the heat rate is vital for ensuring the plant meets environmental regulations and for improving its carbon footprint. 

5.) Profitability and Cost Management 

• In a competitive energy market, the ability to generate power efficiently at a lower cost can determine a plant’s profitability. 

• A more efficient plant (with a low heat rate) can generate electricity at a lower cost and sell it at a competitive rate, improving its market position. 

6.) Benchmarking and Comparison 

• Heat rate allows for comparison between different power plants or even between different technologies within the same plant. 

• Combined-cycle plants generally have lower heat rates compared to simple-cycle plants because they are more efficient. 

• Comparing heat rates can help in determining which plants or technologies are operating more efficiently, or if upgrades are needed. 

7.) Plant Design and Efficiency Targets

• Heat rate is an essential metric in setting and achieving design targets for new power plants. 

• It is used in plant feasibility studies to project energy production and costs over the plant’s lifespan. 

8.) Regulatory Compliance

• Heat rate is often part of performance guarantees in contracts or regulatory framework. Power plants are typically required to meet certain heat rate thresholds. 

• Monitoring it ensures the plant remains in compliance with these agreements. 

9.) Long-Term Planning 

• Over time, measuring heat rate helps power plant operators make data-driven decisions about equipment upgrades, plant expansions, or fuel-switching options, contributing to long-term planning and sustainability.

Effects of Generator excitation

Effects of Generator under excitation 

If a generator is operating in an under-excited condition, it could result in increased fuel consumption for the following reasons.

Understanding under excitation: 

• Excitation refers to the supply of DC voltage to the rotor windings of a synchronous generator establish its magnetic field. 

• Under-excitation means the generator is producing less reactive power than its rated capacity, causing the generator to operate at a lower excitation voltage. 

• This leads to a decrease in the generator’s ability to produce reactive power (leading to a power factor of less than 1), affecting overall system efficiency. 

How under excitation affects fuel consumption: 

1.) Efficiency losses:

o In under-excitation, the generator becomes less efficient, as it may require additional mechanical power to maintain the same real power output. The system may need more fuel to compensate for these inefficiencies. 

2.) Increased Reactive power demand:

o Under-excitation may require the generator to absorb more reactive power from the grid, or it could be unable to supply reactive power efficiently to the load. This often requires the turbine to work harder to compensate, leading to higher fuel consumption. 

3.) Lower Power Factor: 

o Operating under-excitation can lead to a lower power factor (more reactive power consumption), causing the generator to use more fuel to maintain its real power output. A lower power factor typically means that the generator is less efficient in converting fuel into useful electrical power. 

4.) Load imbalance: 

o Under-excitation might also cause an imbalance between real and reactive power output, making the system less stable and potentially requiring more fuel to correct or stabilize the system. 

In an under-excited condition, the generator tends to consume more fuel because it operates less efficiently, requires more mechanical power to produce the same electrical power output, and could need additional fuel to compensate for lower power factor and increased losses. 

Effects of Generator Over-excitation 

Over-excitation refers to the condition where the generator is supplied with more DC voltage to its rotor windings than required for normal operation. This increases the magnetic field strength and causes the generator to produce more reactive power than needed. Here are the key effects of over-excitation on a synchronous generator: 

1.) Increased reactive power output: 

o Over-excitation leads to the generation of more reactive power (VARs), which can be useful in systems that require voltage support. In grid applications, this can help maintain voltage levels at distant loads or stabilize the system. 

o While this can be beneficial for voltage control in certain scenarios, excessive over-excitation can lead to problems, especially if reactive power exceeds the system’s needs. 

2.) Reduced efficiency:

o Increased fuel consumption: over-excitation can reduce the overall efficiency of the generator because producing excessive reactive power often requires the turbine to work harder, thus consuming more fuel to maintain the same level of active (real) power. 

o Losses in the system: Excessive excitation may cause higher losses due to the increased current in the rotor, stator, and other components of the generator. These losses reduce the generator’s overall efficiency and increase fuel consumption. 

3.) Potential for overheating: 

o Over-excitation increases the magnetic field strength, which can result in increased eddy current losses and core losses in the generator. 

o These losses can cause the generator’s core and windings to overheat, potentially damaging the equipment if sustained over time. 

4.) Voltage instability: 

o If over-excitation is too high, it can cause the generator to produce more reactive power. This could lead to voltage instability, where the system voltage becomes too high, potentially causing damage to sensitive electrical equipment or causing voltage regulation problems. 

o Over-voltage can lead to flash-over (insulation breakdown) and can damage both the generator and connected equipment. 

5.) Reduced power factor: 

o over-excitation can lead to a situation where the generator’s power factor is too high (the generator is producing too much reactive power), which may result in inefficient operation of the generator and overall system. 

o A high reactive power output can increase the load on the generator and reduce its overall real power output efficiency, leading to higher fuel consumption for the same real power. 

6.) Excitation control system stress:

o Operating in over-excitation for extended periods can stress the excitation control system. The system may work harder to regulate the voltage, and if not properly manage, this could result in control system failures or other operational problems. 

7.) Impact on system stability: 

o While over-excitation can help with voltage regulation in some cases, excessive reactive power can create instability in the grid or system. If too many generators are over-excited, it could cause excessive voltage to rise and result in voltage collapse or tripping of generators. 

Over-excitation can have both positive and negative effects: 

• Positive: it can help boost voltage support in certain applications and maintain system stability.

• Negative: it leads to inefficiency, higher fuel consumption, overheating, damage to equipment, and voltage instability if not properly controlled. 

Ideally, the excitation of a generator should be carefully controlled to ensure it operates within optimal parameters. Balancing the need for reactive power support without causing negative effects on efficiency, system stability, and fuel consumption.

Useful Power Generation Formula

1.) Electrical Power (DC Circuits) 

P = V x I 

Where: 

P = Power (in watts) 

V = Voltage (in volts) 

I = Current (in amperes) 

2.) Electrical Power (AC Circuit, Single Phase) 

P = V x I x cos Ɵ

Where: 

Ɵ = is the phase angle between voltage and current (power factor)

3.) Electrical Power (AC circuit, Three Phase) 

P = √3 x V x I x cos Ɵ

Where: 

V = line voltage (in volts) 

I = line current (in amperes) 

cos Ɵ = power factor 

4.) Efficiency of Power Generation System 

Eff. = (P out / P in) X 100 

Where: 

Eff. = efficiency (Percentage) 

P out = output power (in watts)

P in = input power (in watts) 

5.) Mechanical Power Output of a Turbine 

P = T x ῶ

Where: 

ῶ = angular velocity (in radians per second) 

6.) Thermal Efficiency of Heat Engines (Carnot Efficiency) 

ἡ carnot = 1 – (T cold / T hot) 

Where: 

T cold = temperature of the cold reservoir (in kelvins) 

T hot = temperature of hot reservoir (in kelvins) 

7.) Heat Rate (Energy Efficiency of a Power Plant) 

Heat Rate = Fuel Energy Input (Btu per hour) / Electricity Output ((kWh) 

• Lower heat rate means higher efficiency. 

8.) Energy Generated by a Wind Turbine 

P = ½ ῤ A v^3 C p 

Where: 

ῤ = air density (in kg/m^3) 

A = swept area of the turbine blades (in m^2) 

V = wind speed (in m/s) 

C p = power coefficient (depends on the turbine) 

9.) Hydroelectric Power Generation

P = ἡ ῤ g h Q 

Where: 

ἡ = turbine efficiency 

ῤ = water density (in kg/m^3) 

g = acceleration due to gravity (9.81 m/s^2) 

h = height of the waterfall (in meters) 

Q = water flow rate (in cubic meters per second) 

10.) Steam Power Generation (Rankine Cycle Efficiency) 

ἡ rankine = W turbine – W pump / Q in 

Where: 

W turbine = work done by the turbine (in joules) 

W pump = work required to pump the fluid (in joules) 

Q in = heat energy added (in joules) 

11.) Photovoltaic Power Output (Solar Panels) 

P = A x E x ἡ

Where: 

P = power output (in watts) 

A = area of the panel (in square meters) 

E = solar irradiance (in watts per square meter) 

ἡ = panel efficiency

Effects on electricity grid if all power comes from renewables: Battery storage, Wind, and Solar.

It would significantly transform the grid and present both opportunities and challenges. 

1.) Intermittency and Variability 

• Solar and Wind energy and inherently intermittent sources of power; solar only generates electricity during daylight and wind turbines depend on wind conditions. This intermittency can always create challenges in balancing supply and demand on the grid. 

• Battery storage helps mitigate this issue by storing excess energy during times of high generation and releasing it during periods of low generation. However, the current capacity of battery storage systems is limited and large scale deployments would be needed to ensure reliability. 

2.) Grid stability and Frequency Control 

• Traditional power plants, especially thermal plants like coal and natural gas, helps maintain grid frequency and stability by providing inertia, the physical resistance to changes in the power grid’s frequency. Renewable sources like solar and wind do not naturally provide this inertia, which can make it harder to stabilize the grid. 

3.) Overgeneration

• On days of high solar and wind output, renewable generation might exceed demand, leading to overgeneration. Without enough storage or demand-side flexibility, the excess energy could be waster and power generation might need to be reduced. 

4.) Transmission and Distribution upgrades 

• Shifting to 100% renewables would require significant upgrades to transmission and distribution infrastructure. Renewable energy sources are often located far from population centres, requiring investments in high-voltage transmission lines to move energy to where it is needed. 

• Local distribution networks would also need to adapt to the “Two-way flow of electricity”, especially with decentralized solar power generation from residential rooftops. 

5.) Energy Storage 

• Energy storage becomes critical in a renewable-dominated grid. 

6.) Decarbonization and Environmental impact 

• A 100% renewable grid would significantly reduce greenhouse gas emissions, making a major contribution to efforts to climate change. Solar, wind and batteries produce minimal emissions compared to fossil fuel-based power plants. 

• However, renewable energy infrastructure requires mining and manufacturing for materials like lithium, cobalt, and rare earth metals, which come with their own environmental impacts that must be managed responsibly. 

7.) Cost implications 

• In the long term, renewable energy sources have the potential to be cheaper than fossil fuels, especially as the costs of solar panels, wind turbines, and batteries continue to fall. 

• In the short term, the transition would involve significant capital investment in new generation capacity, storage, grid upgrades and R&D in advanced grid management technologies. However, the reduction in operational costs would offset these over time. 

8.) Job creation and Economic shifts 

• Transitioning to a renewable-powered grid would create jobs in sectors like solar installation, wind turbine maintenance, and energy storage. However, it could also lead to a decline in jobs in fossil fuel-based industries, which would require retraining and reskilling programs from workers.