TBH, this calculation doesn’t take into account solar cells’ energy conversion efficiency (15%-20%), energy transfer inefficiencies and weather issues, so 1% of land should be multiplied by at least 20.
1 kilowatt of panels in Alice Spring, Australia producing an average of 5 kilowatt hours a day or about 1800 kWh a year
So roughly 5 square metres per 1800 kWh annually, or 360 kwh per square metre
One square kilometre is a million square metres, so we get 360 gwh per square km
Global energy use of 180,000 twh or 180,000,000 gwh, that’s 500,000 square kilometres
Total land area of 150,000,000 square kilometres, so a third of a percent of land area.
Overbuild by 10 times because we haven’t built a global electricity grid, still only 3.3 percent of land area or 2.5 million square kilometres. For context, meat and dairy agriculture uses approximately 40 million square kilometres and urban use is ~1.5 million to 2 million square kilometres.
Alice Springs is in the middle of the desert though, very sunny all the time. It’s not a good place use as the average amount of energy generated for solar panels.
That’s why I added an order of magnitude to the total land area requirement
From a few seconds of googling (so the figure may be wrong), in the UK the average solar panel output per m² is 186kWh per year, about half of the NT figure.
So if everywhere was the UK, we’d need 0.6 percent of total land area.
Because we don’t have a grid that stretches from the northern to southern hemisphere, you’d need ~5 times the amount in winter (already included in the annual average figure used, but we’re looking for a very conservative estimate), so 3 percent of total land area if everywhere was the UK.
You still didn’t take into account day and night, weather and losses due to energy transfer over long distances. And solar cells degrade over time, lowering their efficiency. Calculating only by nominal power is wrong even for coal (capacity factor ~ 60%) and nuclear power (capacity factor ~ 90%), and for solar it varies wildly depending on where it is located. In Arizona deserts it reaches almost 30%, in Bavaria only 12%, and the farther to the North you go, the worse it is.
Addressed in the first paragraph - 1 kw is 24 kWh a day. 5 kWh suggests a 20 percent capacity factor. Degradation is minimal (less than a percent a year).
Why would you be going further north than Bavaria? Bavaria is already very north. 90 percent of the world’s population lives south of Germany, roughly.
Anyway you’ll see the last 3.3 percent of total land area is what would be required if solar only had a capacity factor of two percent.
TBH, this calculation doesn’t take into account solar cells’ energy conversion efficiency (15%-20%), energy transfer inefficiencies and weather issues, so 1% of land should be multiplied by at least 20.
1 kilowatt of panels in Alice Spring, Australia producing an average of 5 kilowatt hours a day or about 1800 kWh a year
So roughly 5 square metres per 1800 kWh annually, or 360 kwh per square metre
One square kilometre is a million square metres, so we get 360 gwh per square km
Global energy use of 180,000 twh or 180,000,000 gwh, that’s 500,000 square kilometres
Total land area of 150,000,000 square kilometres, so a third of a percent of land area.
Overbuild by 10 times because we haven’t built a global electricity grid, still only 3.3 percent of land area or 2.5 million square kilometres. For context, meat and dairy agriculture uses approximately 40 million square kilometres and urban use is ~1.5 million to 2 million square kilometres.
Alice Springs is in the middle of the desert though, very sunny all the time. It’s not a good place use as the average amount of energy generated for solar panels.
That’s why I added an order of magnitude to the total land area requirement
From a few seconds of googling (so the figure may be wrong), in the UK the average solar panel output per m² is 186kWh per year, about half of the NT figure.
So if everywhere was the UK, we’d need 0.6 percent of total land area.
Because we don’t have a grid that stretches from the northern to southern hemisphere, you’d need ~5 times the amount in winter (already included in the annual average figure used, but we’re looking for a very conservative estimate), so 3 percent of total land area if everywhere was the UK.
You still didn’t take into account day and night, weather and losses due to energy transfer over long distances. And solar cells degrade over time, lowering their efficiency. Calculating only by nominal power is wrong even for coal (capacity factor ~ 60%) and nuclear power (capacity factor ~ 90%), and for solar it varies wildly depending on where it is located. In Arizona deserts it reaches almost 30%, in Bavaria only 12%, and the farther to the North you go, the worse it is.
Addressed in the first paragraph - 1 kw is 24 kWh a day. 5 kWh suggests a 20 percent capacity factor. Degradation is minimal (less than a percent a year).
Why would you be going further north than Bavaria? Bavaria is already very north. 90 percent of the world’s population lives south of Germany, roughly.
Anyway you’ll see the last 3.3 percent of total land area is what would be required if solar only had a capacity factor of two percent.