https://www.rapidtables.com/convert/energy/

• solar panel:

• Panel size: 17.6 sq ft

• Power rating: 400W under ideal conditions

• Complete system manufacturing energy: ~6.3 million BTUs (includes inverter, racking, wiring)

• Total coal equivalent: 543 lbs (up from 350 lbs for panel only)

• CO2 formation from manufacturing: about 1,485 lbs CO2 (543 lbs coal → 407 lbs carbon → 1,485 lbs CO2)

• Lifetime energy: 35.6 million BTUs (in New England conditions)

• 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 t- the manufacturing energy cost, but the system is still significantly more efficient than burning coal directly.

COAL AVAILABLE FOR FUTURE MANUFACTURING

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

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

• Total panels needed: 64.8 billion panels o.17.6 billion tons of coal (1.6% of global reserves) o. Could d- 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

• 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.

• 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

• 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 t- recycle without quality loss

• New raw materials must constantly be added t- maintain production

• 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

• Fundamental thermodynamic barrier:

• Need fossil fuels' high temperatures t- manufacture solar panels

• Don't have enough fossil fuels t- maintain closed manufacturing loop

• Electric furnaces can't reach required temperatures with current technology

• N- known alternative for reaching these temperatures at industrial scale

A good - 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 t- produce and transport the panel
• Equivalent t- 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 t- generate the amount of energy that was used t- create it. After that point, it's generating net positive energy. Over its lifetime, it produces about 12 times more energy than was used t- make it.