Important Elements
Storage solutions have a number of key factors that may influence a decision when choosing the correct battery or storage option for a home, power plant or country.
Our comparison focussed on the 3 storage options we chose and the parameters that were comparable were differentiated to determine which storage solution was best. However, for this comparison the limitations were set at 1 module battery for Lithium Ion and Redox and a small Ammonia plant for the ammonia storage.
Below is a table of some of the parameters investigated.
Our comparison focussed on the 3 storage options we chose and the parameters that were comparable were differentiated to determine which storage solution was best. However, for this comparison the limitations were set at 1 module battery for Lithium Ion and Redox and a small Ammonia plant for the ammonia storage.
Below is a table of some of the parameters investigated.
Spider Comparison
After researching each storage option in depth we were able to determine the most important aspects of each option. These aspects are compared below in a spider diagram showing the key differences. Five different aspects were compared for the three storage options; energy density, total cost, environmental implication, round trip efficiency and lifetime.
In the spider diagram the outer points are the most desirable condition. E.g. Towards the value of 1 for cost is the cheapest per unit solution, and for lifetime the longest life.
In the spider diagram the outer points are the most desirable condition. E.g. Towards the value of 1 for cost is the cheapest per unit solution, and for lifetime the longest life.
Results
Energy density: In terms of energy density the lithium-ion battery was the highest with 210 kWh per m^2, the redox flow battery requires much more surface area per kWh and although the capacity of an ammonia plant is much larger it would require a large land mass.
Total cost: The total cost is a unit cost/kWh for each solution and is divided over the expected lifetime of the storage option. Here the redox flow is the cheapest. It was expected that this cost would change during installation depending on inverter costs, costs of materials and maintenance.
Environmental implication: We were unable to conduct a full environmental impact assessment due to time constraints of the project and limited information about ammonia. Therefore, we haven't looked at all the different environmental possibilities and potential damaging factors and instead made an informed judgement of what we feel were the most important factors in terms of environmental implications. What resulted was that the ammonia storage is the one that has the least impact on the environment due to the current lack of recyclability of lithium ion and the extraction methods for the elements in both the lithium and redox batteries.
Round trip efficiency: Here the lithium-ion is the best with around 90% round trip efficiency, the redox battery is at 75% and ammonia around 41%. These round trip efficiencies are taken from manufacturers data sheets and/or journal papers, therefore the information is not from laboratory tests.
Lifetime: The lifetimes differ a lot for each option, the predicted lifetime of an ammonia storage plant is 40 years while lithium ion batteries have only 10 years lifetime.
Total cost: The total cost is a unit cost/kWh for each solution and is divided over the expected lifetime of the storage option. Here the redox flow is the cheapest. It was expected that this cost would change during installation depending on inverter costs, costs of materials and maintenance.
Environmental implication: We were unable to conduct a full environmental impact assessment due to time constraints of the project and limited information about ammonia. Therefore, we haven't looked at all the different environmental possibilities and potential damaging factors and instead made an informed judgement of what we feel were the most important factors in terms of environmental implications. What resulted was that the ammonia storage is the one that has the least impact on the environment due to the current lack of recyclability of lithium ion and the extraction methods for the elements in both the lithium and redox batteries.
Round trip efficiency: Here the lithium-ion is the best with around 90% round trip efficiency, the redox battery is at 75% and ammonia around 41%. These round trip efficiencies are taken from manufacturers data sheets and/or journal papers, therefore the information is not from laboratory tests.
Lifetime: The lifetimes differ a lot for each option, the predicted lifetime of an ammonia storage plant is 40 years while lithium ion batteries have only 10 years lifetime.