Understanding the energy we use can be as complex as navigating the maze of climate change discussions. The term “primary energy” often surfaces in these conversations, representing the raw energy from natural sources like oil, gas, and sunlight before it powers our homes and industries.
Primary energy serves as a benchmark for global energy consumption, reaching into the billions of tonnes of coal, oil, and gas. This measure makes zero-emission energy sources like renewables and nuclear appear insignificant against the vast consumption of fossil fuels. In Australia, for example, fossil fuels still account for over 90% of primary energy consumption.
This portrayal, however, doesn’t tell the full story. Much of the energy in fossil fuels is wasted, and as we transition to electricity, the demand for primary energy will decrease significantly.
Transforming Energy: From Source to Utility
Imagine making orange juice from a whole orange. The entire fruit represents primary energy, while the juice extracted represents useful energy. It’s the useful energy that powers our appliances and vehicles.
Converting primary energy into useful energy involves significant losses, particularly with fossil fuels. For instance, coal power stations are inefficient, converting only 35–41% of coal’s energy into electricity, due to losses at every conversion step.
Using fossil fuels is akin to using a leaky bucket to carry water; much of the energy is lost before it becomes usable.
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Counting Challenges in Primary Energy
Global energy reports often underrepresent the role of renewables due to how primary energy is calculated. Different energy sources delivering the same electricity output are counted differently; for example, coal and nuclear are assigned more units of primary energy than solar, despite producing the same electricity output.
This discrepancy occurs because the energy lost as heat from coal and nuclear is recorded, while free energy from sources like sunlight and wind is not.
The Efficiency Factor
When evaluating energy sources, it’s crucial to consider efficiency beyond raw statistics. Although coal boasts high energy density and conversion rates, significant losses occur during extraction, transportation, and energy conversion.
In contrast, solar panels and wind turbines convert energy directly into electricity without the need for fuel, minimizing energy losses.
Australia is already witnessing this shift, with solar and wind becoming the most cost-effective options for new electricity generation, even surpassing coal and gas.
Electrification: The Key to Efficiency
Transitioning to electric solutions in heating, transport, and industry greatly enhances energy efficiency, reducing the overall energy required for the same output.
Petrol vehicles convert a mere 16–25% of fuel energy into motion, whereas electric vehicles use 87–91% of battery energy effectively.
Moreover, electric heat pumps and induction cooktops significantly outperform their gas counterparts in efficiency, offering a sustainable path forward.
Adopting electric solutions is akin to using an intact bucket instead of a leaky one, ensuring more energy is utilized effectively.
Rethinking Energy Priorities
The daunting task of reducing fossil fuel dependence seems more feasible when focusing on useful energy rather than primary energy. Instead of replacing all primary energy, the focus should be on meeting useful energy needs through clean electricity.
The transition to renewables, storage, and electrification can deliver energy more efficiently, achieving the same goals with less waste and fewer emissions.
Original Story at theconversation.com