The options for using self-generated PV energy have multiplied in recent years. Producing PV power and feeding it into the grid is just one of the many options. Now there is a corresponding solution for almost every application requirement for PV power.
To implement these diverse requirements, a control system needs to monitor the power production as well as to manage the consumption. The Solar-Log Base energy management system was developed from the Solar-Log™ PV monitoring system to handle the ever-increasing requirements. This open-system energy manager serves as a control interface for power production, consumption and grid connection feed-ins.

The basis – PV monitoring

When one has a PV plant on their roof, they naturally want to know how much power it is producing and if it is actually producing the forecasted yields. Using a PV monitoring system is the surest way to collect all of the information and to be immediately notified about malfunctions.

A PV monitoring system records and immediately reports power production fluctuations and failures. There are many causes for plant failures and outages.
It could be something small like a single module malfunctioning – for example, from a lightning strike, hail damage, cable damage or broken glass. On the other end it could be something bigger with a complete breakdown. There are many different degrees of failure. Gradual declines in power production performance are especially critical. When there is no monitoring, such problems are usually only noticed late once the decline reaches an advanced stage. This occurs, for example, when the modules are dirty or the shading continues to increase (e.g. a tree growing near the modules). Additionally, the modules themselves can also cause gradual reductions in the plant’s performance. This includes, for example, microscopic cracks on the cell level and potential-induced degradation (PID).

PV energy Diagram Failure Moduls

Report on technical risks in PV project development and PV plant operation, 2016, EURAC & TUV-RH)

However, PV modules are not the only source of plant malfunctions and yield losses. The inverters and DC-DC optimized inverter systems can also be a source of plant malfunctions.
Based on accredited field studies, it was determined that more than 50% of the causes for PV plant malfunctions and the potentially resulting yield loses can be traced to PV modules and inverters.

PV energy Diagram Failure Inverteres

Report on technical risks in PV project development and PV plant operation, 2016, EURAC & TUV-RH)

 

PV energy Relation Tickets

Report on technical risks in PV project development and PV plant operation, 2016, EURAC & TUV-RH)

 

PV energy Comparison Ticktes Components

Report on technical risks in PV project development and PV plant operation, 2016, EURAC & TUV-RH)

Smarter PV energy – mobility, heating and storage

The next step is power consumption when the PV performance is recorded and monitored. There are many different options depending on the requirements and the plant. When it involves the use of PV power, “Smart Home” applications have undoubtedly made great strides. For example, battery systems, heat pumps and electric cars – all of which can consume self-generated PV electricity – have become increasingly popular in private households and industry in recent years.

Electromobility – greener with PV energy

As a result of this development, the Solar-Log™ has been transformed from being just a PV monitoring system to a comprehensive power management system. In addition to monitoring, the system can also manage electrical appliances and record their power consumption. The integration of charging stations for electric cars plays an important role in this transformation. For example, the energy management system in combination with a Keba charging station provides optimized charging for electric cars. Charge requirement settings ensure that the car always reaches its minimum charge level even when no PV energy is available. When there is a PV energy surplus, the energy manager informs the charging station that there is additional power available to charge the car. Furthermore, data such charging can be recorded and visualized.

PV energy charging

Effect charging of e-cars with the Solar-Log™ energy management system. (Source: Solare Datensysteme GmbH)

Save energy with precise heating controls

Combining photovoltaic with heat pumps offers another potential way to optimize the direct consumption of PV power. The basic idea is to have the power demanding heat pump use the PV power. Depending on how the heat pump is connected to the energy manager, a release signal or a surplus is sent to the heat pump. Heat pumps from IDM CTA, Hoval and Stiebel-Eltron can even be connected to the Solar-Log™ system via their own protocol.

Proactive Operation with Weather Data

Additionally, the Solar-Log™ energy manager along with a heat pump from the manufacturer IDM can integrate the local weather forecast. The weather data is calculated hourly and for two days in advance. This forecast can be used for the advanced planning of the heat pump control. In practice, for example, the heat pump can be set to start at 10:00 am when there is high amount of solar irradiation in the forecast. This prevents the heat pump from unnecessarily getting its operating electricity from the power grid.

PV energy heating

The connection to the heat pump via a grid company blocking signal or protocol depends on the manufacturer of the particular heat pump. (Source: Solare Datensysteme GmbH)

Effectively storing PV energy

Using a heat pump allows PV energy to be saved in the form of heat, but it is also possible to save power directly with a Battery Storage System. Such storage systems provide the most effective solution to have flexible use of PV power. The advantages are clear: The electricity can be “saved” and then used later regardless of the time of day or amount of sun. Integrating battery storage with the Solar-Log™ system allows measured values such as the battery voltage, current charge level and unloading capacity to be directly recorded and displayed. As a helpful analysis option, the energy manage displays the charge history for the last seven days. The plant operator receives additional important information such as the power savings from using the battery and the efficiency of the battery solution. The user sees energy usage from the battery and the savings gained by using this stored power.

PV energy storage

The Solar-Log™ records and displays the battery’s current charging capacity and status. (Source: Solare Datensysteme GmbH)

The perfect solution for every PV plant and every requirement!

The diverse solutions indicate how the use of PV energy can be flexible and customized. However, one also quickly loses the overview and questions inevitably arise: What is the best solution for my requirements and PV plant? How can I use the PV power most effectively? How can I implement this? It is best to call an installer to get answers to these questions (here is a list of installers near you). They will prepare and can also implement a solution based on the technical plant data and the desired use of your PV power. You have all of the options on your side with the Solar-Log™ monitoring and energy management solution.