Elon Musk gave a talk at at the Université de Paris Panthéon Sorbonne (Elon Musk, 2015) during the Paris Climate Change conference in December. During the Q and A, Elon suggests that entire US could be powered by installing solar renewable technology in a ‘little corner of Nevada or Utah’.
Elon Musk just made a very important point about solar energy (Harrington 2015) takes Elon Musk’s comment and expands it by adding the math to work out how much land would be covered in solar panels to generate the world’s current energy consumption. The article uses solar energy conversion at 20%, and only solar power in the equation to determine that an area of 496,805 km2, approximately the size of Spain, would be required to fuel the entire world’s energy needs – that’s all power not just our electricity consumption.
According to the Energy Information Administration (US EIA 2016), “In 2012, world total primary energy consumption was about 529 quadrillion British thermal units (Btu). Primary energy consumption in the United States was about 95 quadrillion Btu, equal to 18% of world total primary energy consumption.”
This would mean that the the U.S would need around 89,425 km2 to generate its energy requirements. The area required for this proposal would consume a fair chunk of Nevada, given that the U.S. state is 286,367 km2 (Wikipedia 2016). But, Musk may be considering solar thermal plants rather than the conventional solar panels. Solar thermal is around 33% efficient when considering the conversion of thermal solar heat (steam) to electricity. This is similar to coal-fired plants which convert the thermal energy of coal into steam and then onto electricity (Monsour, 2003, Unit 2, p.16; Wright, M 2010, p.11). This makes solar thermal 13% more efficient than solar PV farms, thus reducing the land area required for generating the US power requirements.
Note: This argument does not consider the added advantage of solar thermal systems, which can store heat in molten salt to permit electricity generation over a 24 hour period (Wright M, 2010, p. 45).
And what about Australia?
In the Australian context, if we assume that our energy consumption is 10% of US consumption, then we’d need around 9,000 km2 to achieve energy self reliance from solar energy based on the 20% efficiency model. Beyond Zero Emissions (BZE) a renewable energy group based in Melbourne developed a plan for using renewable energy to transition away from fossil fuels.
Their Stationary Energy Plan (BZE 2010, pp. 57-58), is based on a mix of renewables, such as wind, rooftop solar, and biomass renewable. BZE estimates that if the solar component were based on solar thermal technology, we would need an area the size of Kangaroo Island, or an area of 2,760 km2 (or roughly a block 53 km x 53 km).
The BZE proposal is a network of 12 sites across Australia located in areas of high energy irradiation and low population densities. These sites are not situated in strategically important agricultural areas (BZE 2016b).
Beyond Zero Emissions (2016a, 3 January). BZE History. Retrieved: http://bze.org.au/about/history
Beyond Zero Emissions (2016b, 3 January). 100% Renewable Energy in 10 Years. Retrieved: http://media.bze.org.au/zca2020_statenergy_poster.pdf
Musk, E. (2015, 2 December) Elon Musk talks climate change & carbon tax at the Sorbone (2015.12.2). Retrieved from Youtube: https://youtu.be/iavquu6PP9g
Harrington, R. (2015, 15 December), Elon Musk just made a very important point about solar energy, Tech Insider. Retrieved from: http://www.techinsider.io/elon-musk-solar-panels-to-power-the-earth-2015-12
Monsour, P. (2003) Unit 2, Energy Basics, Energy Services, and Demand, Introduction to Renewable Energy Technologies, TAFE Queensland.
US Environment Information Administration (US EIA). (2015, 10 February). What is the United States’ share of world energy consumption, Retrieved from: http://www.eia.gov/tools/faqs/faq.cfm?id=87&t=1
Wikipedia (2016, 2 January), Nevada. Retrieved from: https://en.wikipedia.org/wiki/Nevada
Wright, M, Hearps, P (2010), Zero carbon Australia stationary energy Plan, The University of Melbourne: Melbourne (Retrievable electronically at: http://bze.org.au/zero-carbon-australia/stationary-energy-plan