Off-grid electricity generation … or the future role of geothermal power

Site of Well MON-01, Montserrat, Caribbean (source: Montserrat government)
Alexander Richter 30 Aug 2016

In this opinion piece, I argue that small scale geothermal plants could become an off-grid electricity generation option. What do you think - particularly in the context of island states?

Over the past few years, off the grid electricity generation has been discussed mostly in the context of solar or wind power. Geothermal power never really seem to hit the spot to be even mentioned.

So when I stumbled across some articles recently that were discussing off-grid electricity solutions for Africa, that got me thinking. When we talk about geothermal projects and feasibility of development we often talk about resource risk, economic viability, feed-in-tariffs, and yes mostly also about how close a project is to the grid, or power transmission.

In the greater context of the geothermal energy industry, we mostly look at large scale development, e.g. in East Africa or Indonesia. But with all the risks involved, there are some increasing discussions about the size of development, which also opens the door to scenarios, e.g. for off-grid geothermal power generation.

With a smaller scale power plant, e.g. in the form of wellhead plants, one essentially not only speeds up development and allows for a staged development, but also creates additional markets that normally would be overlooked.

So while the opening for me here was Africa and discussions about bringing electricity to people there, there is a wider context for island states, e.g. in the Caribbean and the Pacific. All have in common to currently depend mostly on fossil fuel based power generation, with large price fluctuations. Many of those islands actually have geothermal energy potential. And while the demand might be small, in the greater scheme, geothermal power plants could have a huge impact, not only providing green electricity but also affordable electricity to these island states.

But, these smaller projects are mostly overlooked, both by developers, but also development banks. Yes, there is still the risk element, but given the size and the impact that these plants could have, one clearly should look at ways of incentivising and supporting development on these islands.

If one looks at the announcement from U.S.-based ElectraTherm yesterday, where it is reported that their small scale ORC unit of 100 kW installed capacity in Beppu, Japan runs of hot “waste” water from a district heating plant without impacting a nearby Onsen, geothermal bath, then one can see that the size of these units actually can be rather small.

So this brings me back to “off-the-grid” solutions. If one considers these offered small-scale geothermal plants, in the case of a binary system described above, could utilise temperatures down to around 80 degrees Celsius, then these plants could also provide a power plant solution to communities that are not connected to a larger (national) grid.

But the situation on these islands with regards to geothermal development is not good, while there are several Caribbean projects, projects in the Pacific have nearly all shut down. The latest announcement by Australian Geodynamics, essentially killed projects in Vanuatu and the Solomon Islands. But there is hope. The Global Geothermal Alliance by IRENA has talked about the small Island Developing States and their sustainable energy initiative. One can only hope that this will support development.

In the greater scale of things, these small projects are likely not pushing geothermal to be the next big thing, but could have a tremendous impact on these small island states.

So I am quite keen to hear from you what you think about smaller scale geothermal development and small-scale geothermal plants. How realistic do you think it is to see “off-grid” geothermal development?