Hydrogen storage in renewable energy systems

In conclusion, the consideration of hydrogen stores should be part of any energy policy aiming to replace environmentally adverse and politically if not resource-wise uncertain reliance on fossil fuels by renewable energy technologies. 

The transportation sector is clearly the sector where a transition to sustainable energy sources is most difficult. For the past several decades, hopes were placed in battery-based electric vehicles, but it has taken long time to reach the technical goals for battery performance, and the economic goals that would make a purely battery-operated vehicle with suitable range become economically acceptable have not yet been reached. As a consequence, automobile manufacturers have lowered the expectations to battery-driven vehicles and instead hope that fuel cell vehicles will be able to meet both technical and cost goals. The analysis in Chapter 4 indicates that this may not be the best approach, because fuel cell-battery hybrids may well turn out to be a better solution, due to the complementary advantages of the two sys- 

If the PEM cell development does not meet the set goals, a possible alternative would be acid polymer cells operating at temperatures aroimd 200°C. However, the development stage of this concept is currently much less advanced, and a shift to this technology will likely have the effect of delaying the deployment of viable vehicle fuel cells in the general automobile manufacturing lines. 

Initial introduction of fuel cell vehicles may be in applications where the range requirements are modest, such as fixed route buses, delivery vehicles and trucks. Also the markets for fuel cell trains and ships seem more interesting that current activities indicate. The auxiliary system components should not be neglected, because as mentioned the cost of filling stations and transport/transmission systems for of delivering hydrogen to these (or producing it on-site) can substantially influence the overall attractiveness of the fuel cell system. 

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