Team 2 Speaking and Writing Assignment: “Prospects for Geothermal Energy”

Friday, March 2

(A) Write a full abstract on your talk (single paragraph 250 word limit)

(B) Talk assignment. The overall purpose is to describe where geothermal energy comes from, what methods are used to extract it, and what role geothermal energy is likely to play in the future. The first chapter of a technical report by MIT (2006) gives a decent overview of the above in context of the U.S.

Please address the following questions.

(1) Where does geothermal energy ultimately come from and what is the average heat flow (mW/m²) in the continents? (Please show the heat flow map of the U.S.)

(2) What are the different ways of extracting geothermal energy and their likely capacity in terms of total energy?

(3) What is the geothermal energy production goal stated in the MIT report and how significant is this likely to be to the total U.S. energy consumption? Would R. Heinberg consider geothermal a “primary” energy source?

(4) How much energy has the U.S. recently used from geothermal? A nice image is given on p. 29 of a DOE report (2008). Please relate this (e.g., as %) to the total U.S. consumption.

(5) What is the EROEI of geothermal energy? And what role is geothermal energy likely to play in terms of our future energy use? Is it likely to be sustainable in the sense that it will continue to be viable after fossil fuels are impractical to use? To answer these questions see the manuscript by Mansure (2011) (please stop by and talk to me about Fig. 2)

Other potentially helpful images and information

http://en.wikipedia.org/wiki/Geothermal_energy (The full MIT report is linked in ref. #21)

Some Conversion factors

1 barrel of oil equivalent (boe)=1.7MWh (i.e., 1.7 MWh/boe)

1 boe = 5.8 x 10⁶ Btu (i.e., 5.3 x 10⁶ Btu/boe)

1 MWh = 3.41 x 10⁶ Btu (i.e., 3.41 x 10⁶ Btu/MWh)

1 kWh = 1 day of hard labor by a very large, fit person

US Energy Consumption

According to Heinberg’s article, the U.S. consumes energy at a total rate of 99 x 10¹⁵ Btu/yr.

This is about (99 x 10¹⁵ Btu/yr)/(5.5 x 10⁶ Btu/boe)/(365 days/yr) = 49 Mboe/day

If 19 Mboe is oil consumption, then about 40% of all U.S. energy comes from oil

In terms of MWh, the total U.S. consumption is (99 x 10¹⁵ Btu/yr) /(3.41 x 10⁶ Btu/MWh)/365=7.95 x 10⁷ MWh/day

Or 3.3 x 10⁶ MW = 3.3 TW.

The U.S. consumption that is not from oil is about 2 TW (60% of 3.3TW ).

The MIT report estimates a total electricity use of 1TW.