Is So-Called Free Energy Any Cheaper? 

Approximate completion time: 15 min

Lesson Objectives

By the end of this lesson, you will:

1. Explain why “free” wind and sunlight still cost money when converted into energy. 
2. Compare the value chain costs of intermittent vs. reliable energy sources. 
3. Understand hydrocarbons (natural gas, oil) as “stored sunlight” and why storage costs matter. 
4. Evaluate how global economics (e.g., China’s solar dominance) affect affordability. 

Question

“If sunlight and wind are free, why would electricity from them still cost money?” See if you can brainstorm 3 to 5 answers why. 

Keep in mind that even though sunlight and wind are free, at least in theory, to be converted to electricity, they need very expensive technology (solar cells, turbines), costly manufacturing, transport, installation, maintenance, and storage systems (mostly batteries) for when the sun isn’t shining or the wind isn’t blowing.  The costs add up making these unreliable, intermittent energy sources less affordable (and not so clean). 

Think and Write

In your notebook, take 3-5 minutes to think about and answer the following questions: 

• If sunlight and wind are free, why isn’t solar or wind power “dirt cheap”? 
• What extra steps, technologies, or costs do you think are needed before “free” sunlight becomes electricity in your house? 
• If energy could be stored for free in the past and saved for us today, would that be more valuable than catching sunlight in real time? 

Pair

Discuss with a partner, family member, or parent/teacher to complete the next section:  

(Hint: Try to challenge each other respectfully and build on ideas) 

1. Compare answers: Did you and your partner both say “infrastructure” (like solar panels, batteries, transmission lines)? 
2. Debate this:   Which is easier to store — today’s electricity or ancient hydrocarbons? Why? 
3. What do you think happens to energy prices when one country (like China) controls most of the solar panel market? 

Share

Discussion Points to Draw Out: 

1. Solar & Wind Tech Costs:
   • Wind & sunlight are free, but panels/turbines = technology = cost. 
   • Manufacturing, land use, maintenance, and storage add hidden costs. 
   • China undercut prices by subsidizing solar panels → now controls the market → can raise prices later. 
2. Storage Costs vs. Free Storage:
   • Electricity storage today (batteries) is expensive and limited. 
   • Oil & gas = “legacy sunlight” stored naturally for free by Earth (ancient photosynthesis + pressure + heat). 
   • Hydrocarbons are like giant “nature-made batteries” we didn’t have to build. 
3. Efficiency Limits:
   • Solar panel efficiency rose from ~3% in the 1950s → ~25–28% today. 
   • But efficiency follows a bell curve → can’t increase forever → cost savings hit a wall. 
4. Nuclear’s Advantage:
   • Nuclear isn’t sunlight, but it delivers massive reliable power density with less land use than wind/solar farms. 

Analogies to Consider 

• Solar/Wind = Streaming Service 🎶 → Cool, new, but you pay monthly, need internet, servers, devices, constant updates. 

• Oil/Gas = Vinyl Records You Already Own 🎵 → Paid for long ago, still works, stored for free, easy to use anytime. 
  
• Nuclear = Spotify Premium Family Plan → Higher entry cost, but once set up, you get unlimited, reliable access. 

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