Types and characteristics of photovoltaic storage systems. Let’s see how to design a storage system in a photovoltaic installation (part 2)
Production or post production systems
Storage systems can be of two types:
- on production side, installed between the photovoltaic system and the inverter
- post-production, installed after the inverter
The production-side systems consist of a single inverter that simultaneously controls the system and the batteries. The transformation of electricity allows to have smaller losses.
Post-production systems have the same function, but they are installed before the inverter. They present a greater energy dispersion, yet it is a convenient solution for those who already have a photovoltaic system, as it can be integrated without having to replace the present inverter.
Types of storage systems in a Grid Connected system
We can distinguish two types of storage systems in a grid connected installation, in particular:
- Storage system with integrated inverter
- Advantages: they are compact, minimal in size and easy to install on new plants.
- Independent storage systems
- Advantages: configurable in a more precise way according to the customer’s load profiles; in fact, the technician can choose between different technologies and storage capacities
There are different types of batteries made of different materials that vary in efficiency and costs. Below we list the batteries used in photovoltaic systems:
- lead acid batteries (gel)
- lithium ion batteries
- lead acid batteries (sealed)
- Nickel batteries
- ead acid batteries (AGM sealed)
- sodium salt batteries
It is important to consider 3 fundamental aspects when choosing a type of battery:
- capacity – how much electricity the battery is able to accumulate and deliver [kWh];
- power – speed which the battery uses to store or release energy;
- number of cycles – the number of minimum cycles for which the battery remains in the conditions specified by the manufacturer.
Designing a photovoltaic system with an integrated storage system using a software
Solarius-PV allows you to design a photovoltaic installation with integrated storage system in a few simple steps
We can start by choosing the type of storage system (AC or DC side connected).
We then can proceed to the sizing of the storage system, where we automatically obtain the number of batteries needed to meet our demand for useful storage capacity.
Subsequently, the software program will represent the storage system positioned in the wiring diagram either on the DC side or on the AC side.
The analysis of the sizing of the storage system can be obtained from the financial point of view, as well as from the energy and design point of view.
Specifically, we obtain histograms or tabular forms indicating the presence of the accumulation system and how it affects the daily, weekly, monthly and annual energy demand of the examined user.
After an analysis of the energy benefit of the storage system (which we find in the technical and financial reports) we can also view the annual budget table with regard to the storage system.
Following the financial analysis with the presence of the storage system, it is also possible to obtain analytical results dedicated to the accumulation, and then to see how this latter one affects the entire installation. We obtain the analysis both in tabular and graphic form.
Below a video about how to activate an accumulation system with Solarius-PV.