The development of microalgal biorefineries, utilizing high-value coproducts, offers a strategy to lower production costs, while the use of saline-tolerant microalgal species contributes to reducing freshwater consumption.

Utility-scale energy storage can help improve grid reliability, reduce costs, and promote faster adoption of intermittent sources such as solar and wind. This paper analyzes the technical aspects and economics of standalone microgrids operating on intermittent power combined with hydrogen energy storage. It explores the feasibility of using dibenzyltoluene (DBT) as a liquid organic hydrogen carrier to absorb excess energy during periods of high supply and polymer electrolyte fuel cells to generate electrical energy during periods of low supply. A comparative analysis is conducted on three power demand scenarios (industrial, residential, and office), in conjunction with three alternative energy sources: solar, wind and wind–solar mix. A mixed system of solar and wind energy can maintain an annual average efficiency above 70%, except for residential power demand, which lowered the efficiency to 67%. A balanced combination of wind and solar power was the most cost-effective option. The current levelized cost of electricity (LCOE) for industrial power demand was estimated to 15 ¢/kWh, and it is projected to decrease to 9 ¢/kWh in the future. For residential power demand, the LCOE was 45% higher due to the demand profile. In comparison, battery storage is significantly more expensive than hydrogen storage, even with future cost projections, increasing the LCOE between 60 and 120 ¢/kWh.

Seawater is an abundant source of critical minerals, but low concentrations make mining uneconomical. Coupling seawater mining with other ocean‐based processes could improve economic feasibility. Here, we investigate coupling it to bipolar membrane electrodialysis (BPMED), an emerging technology developed for ocean alkalinity enhancement (OAE)—a marine carbon dioxide removal (mCDR) pathway. BPMED generates acid and base from seawater, which are key inputs for mineral extraction. Using a demonstration‐scale BPMED system, we characterized and identified mineral‐rich streams within the process for Li ⁺ and Mg ²⁺ recovery. Li ⁺ was extracted using an inorganic sorbent (H ₂ TiO ₃ ) regenerated with BPMED acid, while high‐purity Mg(OH) ₂ was selectively precipitated using BPMED base via a laminar coflow method. Our results show that Li ⁺ and Mg ²⁺ extraction from natural seawater using BPMED‐sourced acid/base streams provide performance comparable to that obtained using commercial acid/base solutions. Preliminary cost–benefit assessments show that Mg(OH) ₂ extraction could generate positive net revenue, but Li ⁺ recovery is uneconomical relative to the value of Mg ²⁺ recovery. Importantly, the alkaline effluent post‐Mg(OH) ₂ recovery retains alkalinity relevant to OAE under tested conditions. Our study demonstrates, for the first time, the feasibility and benefits of integrating mCDR with seawater mining to advance sustainable ocean‐based climate solutions.