Stanford Energy Seminar | Enhanced Geothermal Systems: Are We There Yet?

Abstract: Geothermal energy has undergone a renaissance over the past 15 years, as many new technologies and new countries have joined the industry. Climate change concerns have focused attention on renewable energy, supported by a global ambition to address greenhouse gas reduction. Geothermal developments have accelerated in many parts of the world, both in countries (such as Turkey, Indonesia, Kenya, New Zealand, and the US) that have a traditional interest in "conventional" geothermal resources, as well as countries without a historical community in geothermal energy (such as France and Germany). Some new developments have followed well-worn paths using conventional hydrothermal resources in volcanic regions, while others have struck out in new directions in Enhanced Geothermal System (EGS) projects in nonvolcanic regions. Technology has allowed for developments of conventional resources with lower temperature, restricted water access, and constrained surface utilization. EGS projects have launched in a variety of different directions and places. The use of innovative hybrid plants, lower resource temperatures and enhanced reservoir stimulation has made geothermal energy accessible in a much wider variety of places.
Speaker Bio: Roland N. Horne is the Thomas Davis Barrow Professor of Earth Sciences and Professor of Energy Science and Engineering at Stanford University, and Director of the Stanford Geothermal Program. He was the Chairman of the Department of Petroleum Engineering at Stanford from 1995 to 2006. He served on the International Geothermal Association (IGA) Board and was the 2010-2013 President of IGA. He was Technical Program Chairman of the World Geothermal Congress 2005 in Turkey, 2010 in Bali, Melbourne in 2015, and in Iceland in 2020-2021. Roland is a member of the US National Academy of Engineering and an Honorary Member of the Society of Petroleum Engineers. He is also a Fellow of the School of Engineering, University of Tokyo and an Honorary Professor of China University of Petroleum - East China.

[@zettaiengineer4202]

Do the temperature contours follow uplifted/intrusions of granite as implied by the "Geologic structure" slide? If so, are there advantages to drilling at the base of steep gradients of granite such as in the Eastern Sierras & Central Oregon?

[@alandpost]

With regard to running counter to solar timing -- could you soak daytime power into injecting hot water to store the thermal energy?

[@kevinleecaster2698]

Good lecture as usual Dr. Horne. I can't recall what city, but one recently allowed their public gas utility to switch to a district heating business model. Interested to see how that turns out.

[@Nill757]

Oil and gas fracked wells traditionally use sand and the like to hold open fractures against pressure, w relatively low flow, a 1-2 kg per sec. How are a fractures held open w 60-80kg/sec working to remove sand?

[@Nill757]

The MIT feasibility target was 80kg/s, and 7000N deep, yes? Blue Mountain was 300M deep per this demonstration, yes?

[@rolandhorne8923]

Blue Mountain is about 3000 m deep.

[@Nill757]

How much water loss?

[@Nill757]

Pumping power? PE alone, m*g*h of 80kg/sec, depth 7km is 6MW, w say 60% eff pump, 10MW. Can that ever pay? Once again, much nearer surface, hotter rock seems to be required, ie rare geothermal conditions using traditional, not enhanced methods.

[@mohammadaljubran2456]

Think of thermosiphon effect

[@Nill757]

@@mohammadaljubran2456 I’m aware; I don’t think it significantly applies. You know better? The injection wells and recovery wells and generation system with steam expansion in between would have to somehow be a single phase system w little compressibility over 10km. I don’t see it. I do know some earlier egt pilot projects a few years ago were net loss power.