Solar energy combined with genset or net power: maximum sustainability and reliability

Solar energy is playing an increasingly big part in sustainable emission free energy usage. The challenge in this is to arrange for an installation that is 100% reliable and always provides electricity, even at night or on overcast days. This can be achieved with a solar based power plant. Through off-grid islanding, a grid connection or a combination thereof the solar based power plant offers supply reliability.

Smart regulations
The power plant consists of a solar installation connected to a genset and/or the grid. Depending on the installation it’s possible to add batteries for energy storage. At the heart of the power plant is a smart control panel that can select the most fitting energy source for each moment. Primarily, of course, this would be solar energy. However, during peak demand or when batteries are empty the grid or a genset could provide the necessary coverage. “The idea was born from our vision on the energy transition,” Frans Hullegie explains, Business Development Manager at Bredenoord. “We frequently work for factories in isolated locations, such as in Africa. By adding solar panels and a smart control system between these panels, the grid and the gensets, we can significantly reduce fuel usage and CO2 emission. This, of course, without compromising supply reliability.”

Bre 18 1855 Beeld Infographic Solar Plant

Custom installation, both on grid and off grid
In situations where no AC is available a solar based power plant could provide a solution. This can vary between 100 kW and multiple MWs, with various types of solar panels and, if desired, batteries and gensets as reference for the solar installation and backup for energy supply. A modular power plant can be set up to ensure a fitting installation for each situation. While designing a power plant various variables are taken into account, such as location, consumer profile and solar time, to achieve optimal profit (the balance between initial investment and return time). More and more often the solar based power plant is put to use in places that do have access to AC. The AC functions as primary reference. It is also possible to set up the power plant as a triple installation: solar energy functions as the primary energy source, supported by AC, and backed up by a genset. This way there is always sustainable and reliable energy, available at every location.

Efficient solar installation through smart setup
One characteristic of solar installations is that they often provide more power than necessary during peak demand and, of course, generate nothing at night. Through clever setup it’s possible to optimize usage of the energy peaks and troughs, off grid and without the use of batteries. This is possible by enabling extra users during peak hours. For example: an off grid factory has a freezing installation for raw materials or end product. During the day you can use the extra energy to decrease the temperature in your freezer from -20 degrees to -30. At night your installation can function on minimal energy. The 10 degrees with which you lowered the temperature during the day will provide a buffer. Technically you will have converted your solar energy into cold. This kind of smart setup, also known as load management, can be used for many installations and users. When setting up an off grid solar plant Bredenoord always helps the users come up with the most clever usage to ensure optimal result.

Cosinus phi monitoring essential
Some devices absorb relatively more power than they use practically. This happens because in some devices using AC the current and voltage do not line up. The difference between them is called reactive power. This reactive power varies per device (user). The balance between active and reactive power is known as the cosinus phi.

Schema Energie Off Grid Eng

A solar based power plant should, however, deliver the total power. This is the equation of active power and reactive power, which is called apparent power. The smaller the share of reactive power, the more efficient the installation will be, and as such the higher the return.

Managing cosinus phi off grid
In a solar system that exclusively uses gensets in practice up to 40% of the energy has to be generated by gensets (as primary reference) to allow the installation to generate the total apparent power. Smart regulation of cosinus phi allows you to significantly reduce this. With this regulation the cosinus phi is actively divided between the inverters of the solar plant and the gensets. With the proper balance between these the base load of 40% can be reduced to 5%, which is often easily generated through solar energy. This way lots of fuel can be saved. The bigger the share of the sun, the sooner the installation pays itself back. The efficient regulation of the installation increases output and contributes to the longevity and good state of the components.

Preventing on grid fines by enhancing cosinus phi
Even in solar installations that are connected to the grid and return the gained energy it’s essential to monitor and regulate cosinus phi. Energy suppliers often charge large installations for reactive power if the apparent power deviates too much from the real power. The reactive power must still be generated and transported, without it showing on the meter. Sometimes users can already be fined if the cosinus phi is below 0.9 or above 1.1. By adding a regulation module to an on grid solar based power plant the cosinus phi can be kept within the safe values.

For factories, hospitals and government buildings
A solar based power plant is the ultimate way to provide factories, hospitals, schools and offices in isolated areas and/or areas with lots of sunlight with sustainable energy. Because it’s possible to connect to the grid as well as using an off grid variant with gensets each situation can be fitted with the most reliable solution. Bredenoord uses the power demand of the location as the starting point and offers advices on a complete installation based on that, including cosinus phi enhancement and load management when possible. We can set up the entire installation, but we are also open to collaborations in which we only provide the advice and software. Off and on grid solar plants have already been placed in various places, such as a hospital in Somalia and a fruit drying factory in Ghana.

Please contact Zef Jansen for more information.

Zef Jans

Zef Jansen
Area Manager Solutions

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