Solar

https://www.rapidtables.com/convert/energy/ Standard solar panel:

o Panel size: 17.6 sq ft o Power rating: 400W under ideal conditions o Complete system manufacturing energy: ~6.3 million BTUs (includes inverter, racking, wiring) o Total coal equivalent: 543 lbs (up from 350 lbs for panel only) o CO2 formation from manufacturing: about 1,485 lbs CO2 (543 lbs coal → 407 lbs carbon → 1,485 lbs CO2) o Lifetime energy: 35.6 million BTUs (in New England conditions) o Updated efficiency comparison: 4.7x more efficient than direct coal burning (down from 8x when considering panel only) The addition of the inverter and other components adds about 2.2 million BTUs to the manufacturing energy cost, but the system is still significantly more efficient than burning coal directly.

COAL AVAILABLE FOR FUTURE MANUFACTURING o Original reserves (circa 1800): 4,000 billion metric tons o Remaining reserves (2024): 1,074 billion metric tons o Already consumed: 2,926 billion metric tons o Percentage of original reserves consumed: 73.2% o Current annual consumption: 8.5 billion tons/year o Years remaining at current rate: 126 years

BUDGET o. American consume 307 million BTUs o. Would need 216 Standard Solar panels

o Total panels needed: 64.8 billion panels o.17.6 billion tons of coal (1.6% of global reserves) o. Could do 61 cycles of replacements, or 1,526 years

o. If we calculate for current global population o. Total panels needed: 1.73 trillion panels o. 43.7% of global coal reserves o. Only 2 cycles, Coal reserves would last just 57 years

RECYCLING o We can extend our time by using recycling. o. But we end up with about 200 years of global solar at US consumption levels because each 25-year cycle losing 5% in the recycling process.

o Temperature barriers:

• Several key manufacturing steps require temperatures higher than electric furnaces can achieve
• Current industrial electric furnaces max out around 1800°F
• Silicon purification needs 2200°F (requires fossil fuels)
• Glass manufacturing needs 3100°F (requires fossil fuels)
• Steel production needs 2500°F (requires fossil fuels)
• Only aluminum smelting (1800°F) can be done with electric technology

o Material degradation through recycling:

• Each recycling cycle loses approximately 5% of material
• After 10 cycles only 60% of original material remains usable
• Further cycles continue degrading remaining materials
• High-purity silicon becomes increasingly difficult to recycle without quality loss
• New raw materials must constantly be added to maintain production

o Resource timeline implications:

• Each 25-year global solar cycle would use 43.7% of remaining coal reserves
• Only 2 full replacement cycles possible at US consumption levels
• This doesn’t account for other essential coal uses (steel, cement, etc.)
• Can’t maintain enough high-temperature capability for continuous panel production

o Fundamental thermodynamic barrier:

• Need fossil fuels’ high temperatures to manufacture solar panels
• Don’t have enough fossil fuels to maintain closed manufacturing loop
• Electric furnaces can’t reach required temperatures with current technology
• No known alternative for reaching these temperatures at industrial scale

A good standard reference point for a modern residential solar panel is:

• Dimensions: 65" x 39" (about 5.4’ x 3.25')
• Area: 17.6 square feet (1.64 square meters)
• Power rating: 400 watts under ideal conditions
• Weight: About 40-50 pounds

2. Manufacturing and Transport Energy Cost:

• About 4.1 million BTUs to produce and transport the panel
• Equivalent to about 350 pounds of coal

3. Energy Production:

• Produces about 2 million BTUs annually
• About 50 million BTUs over its 25-year lifetime

The key finding is that it takes about 2.1 years for the panel to generate the amount of energy that was used to create it. After that point, it’s generating net positive energy. Over its lifetime, it produces about 12 times more energy than was used to make it.