Why should we install solar hybrid system in Africa?
The Role of Batteries in Solar Hybrid Systems:
In recent years, electrochemical storage systems have emerged as significant players in the energy transition, alongside renewable sources. Unlike other conventional storage systems such as mechanical, thermal, or chemical, electrochemical storage offers several advantages, including high energy and power density, competitive market prices, and the ability to support continuous charge and discharge applications. Due to their scalability and flexibility, electrochemical batteries have become ubiquitous in our daily lives, powering portable appliances ranging from mobile phones to tablets or laptops. It comes as no surprise that even the automotive sector is transitioning from combustion engines to electric motors, coupled with electrochemical batteries.
In the photovoltaic (PV) sector, batteries have been widely used for the past decade to store excess energy produced by PV panels during sunny hours and utilize it during nighttime. The decision to shift power production to the night can be motivated by various factors, depending on the specific system in place.
In on-grid systems, both at the industrial and residential levels, most installed PV systems do not include batteries. The reason behind this lies in the cost implications. Shifting excess solar energy to the night hours leads to an increase in cost per kilowatt-hour (kWh) and an extended payback period. Providing quantitative examples is challenging as it depends on factors such as electricity bills, scheduled costs, battery prices, and battery capacity. According to our experience in the sector, to double the self-consumption through hybrid system we move from 4-5 years of Pay Back Time, with only the PV, to 9-10 years. For this reason, the majority of the installation is known as “0-injection” or “self-consumption,” where the peak production of the PV system matches the peak load demand.
Addressing Reliability Challenges:
However, if the local grid is unreliable and forces consumers to endure frequent power outages, using batteries becomes a more cost-effective and environmentally friendly solution compared to relying on diesel generators as backups. Industries and hospitals, for instance, benefit from integrating batteries into their systems as it ensures a higher degree of independence from the grid, resulting in a more stable and flexible energy supply. Several situations in Africa have demonstrated the critical need for battery integration, as hospitals were unable to operate in surgical rooms due to grid outages and temporary unavailability of diesel fuel for generators.
Moreover, powering your appliances with your own produced power also has a great advantage in terms of power quality and security. The first is crucial to prevent client appliances, which may be very costly, from being subjected to fluctuating grid power and thus getting spoiled over time. The second improves the resiliency of the industry or hospital in reacting to increases in fossil fuel prices or political instabilities.
Off-Grid Systems:
In the specific case of off-grid systems, batteries assume a pivotal role, offering a practical and indispensable solution. Their integration with photovoltaic (PV) technology becomes paramount to ensure an uninterrupted power supply 24 hours a day. These systems go beyond mere economic optimization and are designed to fulfill specific objectives. Depending on the application, the battery can be appropriately sized to meet the load requirements for two or even three consecutive days. Given the unpredictability of solar resources, these systems are consistently hybridized with small diesel generators as a contingency measure during extended periods of rainfall.
Looking Ahead:
In the next blog, we will enter into detail about the available types of batteries (lead-acid, lithium ion, flow batteries …) discussing which ones are preferred in one case and which in the other. Since the importance of storage in the electrification of the production and consumption sectors is well-known, there are always more and more emerging technologies entering the market. We will go through the most popular ones, describing their pros and cons in commercial and industrial applications.
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