Geo-energy test sites

Our paper published this week shows how important pilot and demonstration projects (PDPs) are to the success of subsurface energy technologies, for example CCS, BECCS, direct air capture and storage (DACCS), aquifer thermal energy storage (ATES), compressed air energy storage, (CAES), and decarbonising heat through district heat networks (geothermal heat, thermal storage). Although these and other technologies have been studied by geologists at laboratory scale and in models and simulations, they require testing at pilot and demonstration scale and in representative conditions not reproducible in labs and models.

PDPs represent bridges between generating basic knowledge and technological breakthroughs on the one hand, and industrial applications and commercial adoption on the other (Hellsmark et al. 2016). PDPs act in the space between (1) public sector investment and private sector investment, and (2) fundamental and applied research and technology development and demonstration (Fig. 1).

Fig. 1. Pilot and demonstration in the context of technology development. TRL = NASA’s Technology Readiness Levels

Our paper identifies gaps in two areas: (1) test facilities to aid the design of low cost, high resolution, unobtrusive seismic and other monitoring for a seismically noisy urban environment with a sensitive human population, for example for ATES in urban areas; and (2) a dedicated through-fault zone test site to understand fault transmissivity and reactivation.

In relation to (1), it is clear that for some subsurface technologies to be viable, for example low temperature aquifer geothermal and heat/coolth storage, they will have to be operated in densely populated urban areas because low grade heat will not be retained if transported far. Low cost, high resolution, inconspicuous and unobtrusive seismic and other monitoring for a seismically noisy urban environment with a sensitive human population needs to be designed. Subsurface monitoring has to-date mainly been concerned with oil and gas installations but in many low carbon geo-energy technologies monitoring is more difficult than in oil and gas; for example in geothermal, cold/warm water interfaces are harder to detect than oil/gas or gas/water contacts. PDPs for ATES and coal mine energy are in development, for example the Rijswijk Centre for Sustainable Geo-energy (RCSG) which considers testing of new multilateral drilling techniques known from the oil and gas sector to reduce the footprint of drilling at the surface. The Technical University Delft is developing various low cost, inobtrusive monitoring methods. The UKGEOS Glasgow Observatory also aims at novel monitoring techniques such as electrical resistivity tomography. However a range of PDPs researching monitoring techniques for different geologies probably need to be developed.

For (2) there is a need for test facilities to analyse the reactivation and transmissivity of faults. The occurrence of faults places extra risks on subsurface technology and development because faults are the locus for seismic events and because faults can both transmit and prevent fluid flow. This has implications for hydrocarbon production and seismicity, geothermal energy production, wastewater disposal in depleted reservoirs, CCS, and well as natural gas and hydrogen storage.

Reference

Hellsmark, H., Frishammar, J., Söderholm, P., and Ylinenpää, H. (2016). The Role of Pilot and Demonstration Plants in Technology Development and Innovation Policy. Res. Pol. 45, 1743–1761. ISSN 0048-7333. doi:10.1016/j.respol.2016.05.005

Prof Mike Stephenson is available for consultancy

Mike lead the BGS £31 million UKGEOS proposal to develop two geoenergy test sites, securing the grant for BGS from the UK Government. He is a leading authority on infrastructure for geo-energy in the UK and is available for consultancy.

Web: https://www.stephensongeoscienceconsultancyltd.com/

Email: mikepalyno@me.com

Read the paper here.