What is OAE?

Also known as Ocean-Based Carbon Dioxide Removal (oCDR) or Marine Carbon Dioxide Removal (mCDR).

Under natural conditions, rocks weather over millions of years, increasing the alkalinity of seawater and allowing the oceans to absorb more CO₂ from the atmosphere. 

This is an approach to carbon removal that involves adding alkaline substances to seawater to accelerate the ocean's natural carbon sink. Adding alkalinity to the ocean converts dissolved inorganic CO₂ in seawater into bicarbonates and carbonates, which are stable forms of carbon with a lifetime of approximately 10,000 years. 

The resulting CO₂ deficit in surface waters is quickly rebalanced via a net movement of atmospheric CO₂ into the ocean to re-establish equilibrium.

What does OAE look like at Tufts Cove, Nova Scotia?

During energy generation, the plant utilises steam turbines and requires large volumes of water for cooling its systems. The outfall is used to discharge this cooling water. This outfall acts as a conduit to add a high-solids content alkaline slurry into the receiving marine waters of the Halifax Harbour and Bedford Basin. 

The alkaline substance is a byproduct of magnesium calcination and consists primarily of magnesium oxide. This is imported from Spain in approx. 1.2 metric tonne bulk bags. 

Both upstream and downstream of the addition point,  chemical and environmental properties of the water are continuously monitored to ensure regulatory compliance.