Energy Storage functions and benefits
When choosing a hybrid or off grid photovoltaic system, it is important to know the energy storage functions and benefits, while also checking certain criteria depending on the use the system will have.
The act of integrating an energy storage solution into a photovoltaic system, or acquiring a hybrid solution since day one, allows consumers to apply some of the following functions in their system:
- Self-consumption maximization: allows the user to not only have an energy backup, but also use it when its more convenient to save money, for example during cloudy days.
- Micro-network: in the event of a failure of quality or continuity of the electric service, a hybrid system allows to partially or totally supply the electric operation, avoiding operational costs from emergency plants, production stoppages, or maintain the quality of the energy while the fault is restored.
- Displacement of charges: when operating under an hourly rate, an energy storage system allows to save money by using the rate in favor of the user, using the batteries capacity in “peak” hours and charging the batteries in “night” hours. This is known as Arbitration.
- Consumption peak leveling: it is the most known function of the energy storage systems, in which the consumer takes advantage of the ability of the hybrid system to deliver firm power (kW) and thus do not buy the power from the public network, but only the difference.
Criteria to evaluate before choosing an energy storage solution
Chemistry
In greenenergy we are committed to the latest technology. There are new technologies that have been designed to be combined with photovoltaic systems. The chemicals that are commercially available are those made out of LFP (lithium ferrosphosphate) and NMC (nickel, mangnesium and cobalt). In Costa Rica, the most used is Lead-Acid because of its low cost, however it is inefficient regarding maintenance and life cycle
Depth of Discharge(DoD)
New technology batteries allow to extract about 80-90% of the designed capacity (kWh), this means that they can be fully discharged without damaging the equipment.
Cycles
It refers to the typical process of discharge an recharge of the solution. A good solution should have the capacity of delivering at least 4000 cycles to a 90% DoD before it must be substituted. If a cycle is used per day, the battery should be changed after 11 years, being this the maximum usage of the asset.
Warranty
All experienced brands should offer at least 10 years of warranty on battery capacity. This shows how the energy storage will function, considering usage over time. A responsible supplier should deliver operational curves, technical sheets, quality certifications, amongst others.
Written by: Ignacio Salazar, Commercial Director, greenenergy®.
