PNNL

Abstract

Utility-scale energy storage can help improve grid reliability, reduce costs, and promote 11 faster adoption of intermittent renewable sources such as solar and wind. This paper analyzes the 12 technical aspects and economics of stand-alone microgrids operating on renewable power com-13 bined with hydrogen energy storage. It explores the feasibility of using dibenzyl toluene (DBT) as a 14 liquid organic hydrogen carrier to absorb excess energy during periods of high supply and polymer 15 electrolyte fuel cells to generate electrical energy during periods of low supply. A comparative anal-16 ysis is conducted of three power demand scenarios, industrial, residential and office, in conjunction 17 with three renewable energy sources, solar, wind and wind-solar mix. A mixed system of solar and 18 wind energy can maintain a yearly efficiency above 70%, except for residential power demand, 19 which lowered the efficiency to 67%. A balanced combination of wind and solar power was the most 20 cost-effective option. The current levelized cost of electricity (LCOE) for industrial power demand 21 was estimated to 15 ¢/kWh, and it is projected to decrease to 9 ¢/kWh in the future. For residential 22 power demand, the LCOE was 45% higher due to the demand profile. In comparison, battery stor-23 age is significantly more expensive than hydrogen storage, even with future cost projections, in-24 creasing the LCOE between 60-120 ¢/kWh.