Can St. Vincent overcome the main problem with its Geothermal project?

By Demion McTair. Updated 5:27 p.m., Saturday, June 13, 2020, Atlantic Standard Time (GMT-4).

Discussion – St. Vincent and the Grenadines’ government took a bold and ambitious step to conduct geothermal energy exploration in the country.

The government engaged experts and leading industry players to help guide its exploratory and drilling phases of the project.

These include Reykjavik Geothermal and Emera, large players in the global geothermal energy production sector.

Cost, heat, technical equipment and resources are not issues affecting the project.

Some US$32.49 million dollars had been estimated to cover costs of the project, including US$21.5 million, or 66.17 percent of estimated costs going towards drilling.

Also included in the US$32.49 million are technical assistance drilling of US$792,000 from the government of New Zealand; Project development cost — from 2013 to 2019 — of US$5.98 million from the equity partners, Reykjavik Geothermal and Emera, and project management from April 2019 from the government of St. Vincent and the Grenadines, of US$650,000, for a total of US$32.49 million.

The one major issue for the project, however, was confirmed in late 2019 by technical experts. That issue is permeability of the rocks/soil where drilling has been done for three (3) wells.

The National Academy of Sciences, Engineering and Medicine (NASEM) states that Geothermal energy is produced by the heat of Earth’s molten interior. 

“This energy is harnessed to generate electricity when water is injected deep underground and returns as steam (or hot water, which is later converted to steam) to drive a turbine on an electric power generator”, – NASEM says. 

Even though there is enough heat discovered in St. Vincent’s three (3) drilled wells (155 degrees Celsius, 220 degrees Celsius, and 230 degrees Celsius, respectively), the ability for water to pass through these wells is a problem.

This is what officials mean when they say there is a permeability problem.

When permeability is considered, what is looked at is how quickly and easily water flows through rock or soil.

If the water flows through the rock/soil fast, then the rock/soil has a high permeability.

But, if water flows through the rock/soil slowly, then the rock/soil has a low permeability.

So far, where the drilling has taken place in St. Vincent, at an area on the outskirts of the La Soufriere volcano called – Bamboo Range, the permeability is shown to be low.

The location was chosen by experts after years of studies, including extensive surface exploration by Raykjavic Geothermal as a mitigation measure.

Drilling, however, uncovered that there were tight fractures in the rock/soil.

Prime Minister Dr. Ralph Gonsalves said in Parliament in January 2020 that information provided by the technical persons involved with the project is that the results “in relation to the permeability have not gone favourably due to the very tight fractures that have limited the permeability”.

Though permeability is an issue, temperatures are not. Dr. Gonsalves said “the tested temperatures on the wells were adequate for geothermal power”.

Is there any hope for a way forward?

It will be good to look at the situation at the three wells to get a clear picture of prospects for going forward.

The final analysis

July 2020 was supposed to be the time period for an updated economic report on the project after corrective measures and continued stimulation of wells.

But, due to the COVID-19 pandemic, it is possible for this timeline to be revised and pushed back.

The analysis is to come after all testing and advanced efforts as well as stimulation at the wells for permeability improvement.

In early June 2020, Prime Minister Dr. Ralph Gonsalves said equipment is to arrive to test the power which exists at the Bamboo Range area.

When those tests are done and completed, a decision would be made as to the continuity of the project.