Why geothermal heat power plants need to be modular, scalable and standardized
Recordning from Geothermal Resources Council Annual meeting October 2018
Traditional geothermal heat power plants, both binary and steam-turbine-based, have followed a familiar strategy of implementation for many years. A step-by-step roadmap from identifying and assessing the resource, testing and drilling, building and finally operating the power plant.
This strategy has created many successful projects, but also nearly as many failed or abandoned projects where previously robust financial models have collapsed because of long and expensive drilling campaigns.
Even successful projects can take anywhere from three to eight years, lengthy periods where capital remains at risk, before any revenues can be seen.
Large capital expenditures combined with lengthy projects are two big reasons why geothermal heat power has played a limited role in the renewable revolution.
Change the technology
At Climeon, we believe that by changing the technology behind the geothermal power plant, it is possible to reduce the risks and timelines of projects, thereby creating revenues earlier. With lower risks the geothermal market will become more acceptable and bankable – and that will increase its market penetration.
We have already seen positive results in Iceland with this model. In a saturated market, the potential offered by our technology has re-awakened the opportunity for new geothermal developments within the country.
By utilizing standardized 150 kW units that works efficiently in the approx. 80 – 130°C temperature range, Climeon is able to cover a large portion of the addressable geothermal market with a standard product. The units can be delivered as and when they are needed. This means that a well can be tested, and then, based on the results, the relevant number of units can be deployed within a couple of months.
Unlike traditional geothermal projects this means that revenues can be realized from the first wells. Also, by generating power early, and proving the viability of the resource, the plant can be refinanced at an earlier stage, at a lower rate, freeing up more capital for further development.
Thanks to our standardized units, we can ensure reliability, cost competitiveness, availability of spare parts and spare units. Additionally, the units can easily be moved for use at another site, or even resold.
Flexibility ensures maximal output
Many traditional geothermal projects have suffered due to changing resource conditions. When the plant and its equipment is made to order it’s difficult to adjust it to new conditions.
Using a large number of small and standardized units means that it’s possible to scale the power plant up and down as required. This not only makes the best economical use of the equipment, it also ensures that the equipment is usually operating at peak efficiency.
For example, take a 10 MW power plant operating with a single turbine 10 MW binary solution. If the flow to the power plant were reduced to approximately 50% of the design flow, we would expect power output to reduce to approximately 25 – 30 % of the power production, based on the exact design specifications. This loss of efficiency is typical when plants are operating away from their design window.
With the Climeon units, since the number of units in operation can be reduced, or even relocated, the units that remain in operation can still operate with 100% of their design load and therefore the expected power output of the plant would be 50%, corresponding to the design flow in operation.
Like all mass-produced products, any bugs in the equipment can be ironed out during the test phase, ensuring that the units that reach the field have been through iterations of testing. This ensures long-term reliability, along with standardization of spares packages, and maintenance regimes.
And if a single unit fails there are always other units to spread the increased flow and temperature input among, minimizing any loss in efficiency.
Bigger does not equal better
The traditional argument against small standard plants has focused on the higher efficiency of the big, made-to-order plants. That argument does not hold up since Climeon’s modules achieve higher efficiency than have been possible with small units in the past.
And when you take into consideration the other points I have addressed in this article – quick deployment, scalability and the standardized design – it is easy to see that big is no longer better.