Comparing Renewable Energy Systems: Which is Best for Sustainable Homes?

As the world pivots toward renewable energy, understanding the best way to supply and store this energy in homes is crucial. A recent study investigates three different energy supply scenarios for a typical residential building in Tangier, Morocco, which has a Mediterranean climate. The focus was on combining renewable energy systems—solar panels and wind turbines—with different storage methods: batteries and hydrogen.

Three scenarios were explored:

1. Direct Energy Supply to the Grid: This scenario sends the electricity generated from solar panels and wind turbines directly to the home and sells any excess to the grid.
2. Battery Storage: Here, any surplus energy is stored in batteries, allowing the home to use this stored power later when the sun isn’t shining, or the wind isn’t blowing.
3. Hydrogen Storage: In this approach, excess electricity is used to produce hydrogen through electrolysis. The hydrogen is then stored and later converted back into electricity using fuel cells.

Key findings:

• Energy Efficiency: Both the battery and hydrogen storage scenarios can theoretically cover 100% of the home’s energy needs, while the direct-to-grid approach only covers 52.56%.
• Environmental Impact: The direct-to-grid scenario was the most environmentally friendly, with a carbon payback period of just one year and an annual reduction of 18.2 tons of CO₂ emissions. The hydrogen and battery storage options reduced emissions by 14.82 and 15.13 tons of CO₂ per year, respectively, but had longer payback periods.
• Economic Viability: Financially, the direct-to-grid scenario also came out on top, offering the shortest payback period (5.8 years) and the lowest cost per unit of electricity (5 cents per kWh). The battery storage scenario followed, while hydrogen storage proved to be less economically feasible, with a payback period of over 16 years and a higher energy cost.

For homeowners and policymakers looking to implement sustainable energy solutions, this study offers clear insights. While battery and hydrogen storage systems can provide full energy coverage, the direct-to-grid approach is currently the most cost-effective and environmentally friendly option. However, as technology advances, especially in hydrogen storage, these dynamics could shift, making such systems more viable for widespread use. This research underscores the importance of carefully evaluating the balance between energy efficiency, environmental impact, and economic feasibility when designing sustainable homes for the future.

Source

Assessing the 3E performance of multiple energy supply scenarios based on photovoltaic, wind turbine, battery and hydrogen systems, Journal of Energy Storage, 2024-10-01