Fossil-based power generation causes 28 % of all CO2 emissions. The scenario to cut CO2 drastically includes a significant amount of intermittent renewable energy generation such as wind and solar power which causes unbalances in the electrical system. Demand side solutions for instance, can solve the problem to some extent, but to enable a substantial increase in weather dependent power generation the true enabler is fast response and large-scale storage.
The Only Mature Technology
Today, there is only one mature technology filling the criteria of response times and scale, and that is pumped hydropower. This technology has been deployed the first time in 1929, and accounts for over 94 % of all stored power generation today. However, only 3 % of all produced electricity is stored, and the need is immense and rapidly increasing. It is estimated that 620 billion USD will be invested in energy storage by 2040. Pumped hydro technology is a true enabler for the energy transition for 2 reasons:
- Modern pumped hydro technology can store large amounts of energy and is suitable for bulk storage both at a system level by for instance large energy producers, and behind the meter for large industries such as mines or steel works with a high baseload.
- Modern pumped hydro technology is contrary to many beliefs, responding fast in only seconds. It is a very efficient solution for grid balancing services such as frequency control. The frequency variability is steadily increasing with the amount of intermittent power generation, and with fast responding pumped hydropower substantial amounts of power can be reserved for this already today.
The drawback for traditional pumped hydropower is that it has been involving the construction of open dams above the ground, often in open systems with running water. This increases the risk of environmental impact, lengthy permitting processes, and high construction costs.
The Recipe: Mine Storage
Mine Storage International AB is a company who has a recipe for this, where modern pumped hydropower is deployed in underground mines. These cavities offer a closed-loop environment with little environmental impact, high elevation of the heads and existing infrastructure such as grid connection, security systems and roads and elevators.
This lowers the CAPEX as construction is carried out in existing premises and costs are accordingly reduced. With a closed loop system where the same water is circulated, the environmental impact is limited, and project lead times shortened. Mine Storage has a high round efficiency of 70-80 % and a lifecycle of 60 years, and with an increasing demand of balancing services and electricity price volatility, it makes the solution attractive from both a financial and sustainability point of view.