How to shift from primitive heat to modern work. Our energy system is stuck in the past. Fire has been our primary source of energy for over a million years, providing the essential heat needed to survive.
Originally published September 10, 2024 by Rocky Mountain Institute. Authored By Daan Walter, Sam Butler-Sloss, Kingsmill Bond View full article HERE.
Introduction
Our reliance on fire made sense when our principal energy needs were purely for heat. However, today’s energy demands have evolved far beyond this primal necessity. Unlike in past millennia, we now require more work than heat: we desire mobility, motors, electrical appliances, and data processing in greater quantities than we do warmth. Despite this transformation over the past century from heat demand to work demand, our fundamental energy supply methods have not changed much, and are still mostly heat generation. This has led to incredible inefficiency, which we describe in a prior article.
We need energy sources fit for an era of work demand, not heat demand. Fortunately, thanks to the rapid growth and cost decline of solar, wind, and electrification, “firepower” faces inexorable decline.
Summary
- New energy for a new era. As we transition from fossil fuels to renewables and electric cleantech, our energy system is set to nearly double in primary-to-useful energy efficiency. This is driven by the fundamental physics of heat and work.
- A simple way to look at the complex energy system. Energy supply comes as either heat (from burning fuels like coal and gas) or work (from moving electrons with hydro, solar, and wind). The energy services we require mirror this: some require heat (e.g., industry and building heat), others work (e.g., transport and engines). Heat sources are good at providing heat (50%–70+% efficient), and work sources excel at delivering work (70+% efficient).
- The heat and work mismatch. Today, over 95% of our energy comes from heat supply, yet most of what we need is work. But converting heat to work is only about 33% efficient on average, and given the laws of thermodynamics, it cannot get much higher. This leads to massive energy losses of over 200 EJ per year, making up nearly 60% of all global energy waste.
- A century of growing supply-demand divergence. A hundred years ago, our energy needs were mostly for heat, so sourcing mostly heat supply made sense. While our needs shifted to mostly work services today, our energy supply remained mostly heat, leaving us with a century’s worth of compounded inefficiency.
- We found a solution: renewables get straight to work. Renewables generate electricity directly, bypassing the inefficient conversion from heat to work. This allows them to outperform traditional energy sources while boosting overall efficiency.
- A leap in energy productivity is coming. As renewables replace fossil fuels, we’ll see a massive, once-in-a-century leap in energy productivity — similar to the post-World War II boom when oil and gas took over from coal and biomass.
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