heating since 1969, today supplying geothermal heat to 250 000 households via 50 heating networks.8
Risk sharing While it can provide a consistent renewable energy source, there are certain risks associated with geothermal energy relative to other complementary low-carbon energy solutions, such as wind or solar. Accessing a new geothermal resource involves not only upfront drilling expense but also geological and operational risks, which could make investment more challenging to attract. Yet the large, long-lived, low land-footprint, baseload and flexible energy supply that can be delivered in a success case is very attractive, both from a cost and environmental perspective. While solar and wind energy models are well understood, geothermal projects are highly specific to their local context. This requires a special kind of expertise. Detailed upfront planning, geological evaluations, and overall technical and commercial strategies to reduce risk are critical to the success of these projects.
Figure 1. Example of subsurface input parameters to help identify geothermal sweet spots in South America.
Figure 2. Machine learning derived geothermal heat predictions compared to existing and planned geothermal developments.
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Heat is not easily transported, unless the temperature is high enough to turn it into electricity. Therefore, even a large geothermal resource is not necessarily viable – it also may need to be in reasonable proximity to where the heat is needed. This makes geothermal prospecting very different to mineral or hydrocarbon exploration where a resource, once discovered and developed, can be potentially shipped anywhere in the world. Most deep geothermal exploration aims to identify areas with higher temperatures (high geothermal gradients) where drilling is shallower and thus less expensive. Geothermal developments have sensitive profit margins and, if used for heating rather than electricity generation, they need a local market so early integration with the right information is critical to make projects viable.
Identifying the best areas for geothermal Getech brings together its geoscience data, geospatial software products, and skills in geothermal energy to enable rapid identification of sites highly prospective for this type of energy – lowering risk, increasing profit-margins, and ultimately reducing payback times and returns in geothermal projects. The company’s approach is to apply these unique data, products, and skills to upscale the geothermal opportunity through its Heat Seeker solution, mapping geothermal favourability by combining geoscience and market factors with geospatial machine learning analytics. Heat Seeker incorporates proprietary data as well as public domain sources, using data sets to frame the modelling of temperature, crustal structure, heat flow, and geothermal system boundary conditions (Figure 1). Some of these are derived from gravity or magnetic data using established methodologies, such as the multi-geophysical inversion method for estimation of radiogenic heat production in the crust presented by Hokstad et al., (2017).9 In a recent project, Heat Seeker was used to pinpoint favourable locations for geothermal energy developments in South America. In order to create a surface heat flow prediction map, a variety of machine learning algorithms were tested. This was based on a number of input data sets, such as deep earth structure and temperature constraints, volcanism, and geothermal sites. The model was trained on data sets from the US, a country that has tectonic similarities with the area of interest and already has comprehensive heat flow data useful for crustal scale modelling. Once the accuracy of the algorithm was proven, it was then applied to an area of interest in South America bordering Chile, Bolivia, Paraguay, and Argentina. The resulting machine learning output highly correlates with known volcanic geothermal projects in the area (black dots on the map in Figure 2), modified from Pesce et al., (2014) 10 and Bona and Coviello (2016).11 There are some interesting results worthy of further investigation, including high heat flows in the shared
