Published by Patrick Mutisya · 14 days ago
Understanding the advantages and disadvantages of different energy sources helps us evaluate their suitability for meeting the world’s energy needs. The assessment criteria are:
Coal is a solid carbon‑rich rock formed from ancient plant material. It has been a major source of electricity for many decades.
| Factor | Assessment |
|---|---|
| Renewability | Non‑renewable – takes millions of years to form. |
| Availability | Abundant reserves worldwide, but unevenly distributed. |
| Reliability | High – can be stored and burned on demand. |
| Scale | Very large – capable of generating gigawatts of power. |
| Environmental Impact | High CO₂ emissions, air pollutants (SO₂, NOₓ), ash disposal problems. |
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Oil is a liquid hydrocarbon mixture extracted from underground reservoirs and refined into fuels such as gasoline and diesel.
| Factor | Assessment |
|---|---|
| Renewability | Non‑renewable. |
| Availability | Large global reserves, but geopolitically concentrated. |
| Reliability | High – can be stored and transported. |
| Scale | Large – powers transport, industry and electricity generation. |
| Environmental Impact | CO₂ emissions, oil spills, air pollutants. |
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Natural gas is primarily methane (CH₄) and is used for heating, electricity generation and as a feedstock for chemicals.
| Factor | Assessment |
|---|---|
| Renewability | Non‑renewable. |
| Availability | Abundant in many regions; can be transported via pipelines or LNG. |
| Reliability | High – can be stored as compressed gas or liquefied. |
| Scale | Large – major contributor to electricity grids. |
| Environmental Impact | Lower CO₂ per MJ than coal, but methane leakage is a potent greenhouse gas. |
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Energy is released by fission of heavy nuclei (e.g., \$^{235}\$U). Reactors convert heat to electricity.
| Factor | Assessment |
|---|---|
| Renewability | Non‑renewable (uranium finite), but fuel use is very low per unit energy. |
| Availability | Uranium resources are globally distributed; breeder reactors could extend supply. |
| Reliability | Very high – provides baseload power 24/7. |
| Scale | Large – single plant can produce >1 GW. |
| Environmental Impact | Low CO₂ during operation; issues include radioactive waste, accident risk, and mining impact. |
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P \cdot cells convert sunlight directly into electricity using the photovoltaic effect.
| Factor | Assessment |
|---|---|
| Renewability | Renewable – sunlight is virtually inexhaustible on human timescales. |
| Availability | Widely available, but intensity varies with latitude, season and weather. |
| Reliability | Intermittent – generation only when sun shines; requires storage or backup. |
| Scale | Modular – from small rooftop systems to large solar farms (hundreds of MW). |
| Environmental Impact | Low operational emissions; manufacturing involves hazardous chemicals and energy use. |
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Wind turbines convert kinetic energy of moving air into mechanical rotation, then electricity.
| Factor | Assessment |
|---|---|
| Renewability | Renewable – wind is a natural, ongoing phenomenon. |
| Availability | Best in coastal, offshore and high‑altitude sites; variable. |
| Reliability | Intermittent – depends on wind speed; needs grid integration or storage. |
| Scale | From single turbines (≈2 MW) to offshore wind farms (>1 GW). |
| Environmental Impact | Low emissions; concerns include visual impact, noise, and bird/bat collisions. |
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Water flowing through turbines generates electricity; can be from large dams or run‑of‑the‑river schemes.
| Factor | Assessment |
|---|---|
| Renewability | Renewable – water cycle is continuous. |
| Availability | Depends on geography; abundant where rivers have sufficient flow and head. |
| Reliability | High – can provide baseload and rapid load‑following. |
| Scale | From small micro‑hydro (<100 kW) to massive dams (>10 GW). |
| Environmental Impact | Low emissions; however, dams can disrupt ecosystems, displace communities, and affect sediment transport. |
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Heat from the Earth’s interior is used directly for heating or to drive turbines.
| Factor | Assessment |
|---|---|
| Renewability | Renewable on human timescales – heat flow is continuous. |
| Availability | Limited to tectonically active regions (e.g., Iceland, parts of USA, Philippines). |
| Reliability | High – provides steady base‑load power. |
| Scale | Typically tens to hundreds of MW per plant. |
| Environmental Impact | Low emissions; possible release of dissolved gases and mineral scaling. |
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Organic material (wood, agricultural waste, dedicated energy crops) is burned or converted to bio‑fuels.
| Factor | Assessment |
|---|---|
| Renewability | Renewable if biomass is replanted or waste is used sustainably. |
| Availability | Widely available, especially in agricultural regions. |
| Reliability | Relatively reliable – can be stored and dispatched. |
| Scale | Can be scaled from small domestic boilers to large power stations. |
| Environmental Impact | CO₂ released on combustion, but considered part of short‑term carbon cycle; land‑use change can be an issue. |
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These marine technologies harness the kinetic energy of ocean tides and surface waves.
| Factor | Assessment |
|---|---|
| Renewability | Renewable – driven by gravitational interaction with the Moon. |
| Availability | Limited to coastal areas with strong tidal ranges or wave climates. |
| Reliability | Predictable (tides) but still variable; wave energy is less predictable. |
| Scale | Currently small‑scale (few MW), but potential for larger farms. |
| Environmental Impact | Low emissions; possible effects on marine habitats and navigation. |
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