‹ BackHN Continuity

Thread

Sustainable energy without the hot air (2008)

150 points · 92 comments · 0sake_rs

  1. _aavaa_ · · focus · HN ↗
    The books is good(ish) for it's time, but some of its analysis and forecasts are fundamentally flawed since it falls for the primary energy fallacy by comparing the chemical potential energy (in J) directly to electrical energy (also in J). The two are fundamentally different things and called be compared 1:1. E.g. To heat up your home with natural gas you need ~1J of chemical energy to get 1J of heat into the home, but with a electric heat pump you only need 1/6 J to get 1J of heat.

    It is also a product of its time in terms of wind/solar vs nuclear. His forecasts of the impact of solar and wind is based on prices and performance from 2008. Prices have come down an order of magnitude since then, and performance and lifespan have increased drastically.

    1. nikilr · · focus · HN ↗
      wait how does that work? because you're borrowing the heat from somewhere else?
      1. dragonwriter · · focus · HN ↗
        Yes, that’s why it is called a “heat pump”. It leverages the temperature change from compression expansion of a refrigerant that cycles in a loop to gather heat from one environment and deliver it to another, so that (within limits of temperature on both ends) it can heat or cool a targeted space, doing the opposite elsewhere—outside (or in the ground, for a geothermal system), when we are talking about the first space as a building, generally.
Open on Hacker News to reply ↗

Unofficial Hacker News client; not affiliated with Y Combinator.