Grid Feed-In Prohibited — Energy Management Desirable

Energy management systems in companies in Nicaragua prevent solar power from finding its way into the utility grid. In this Central American country, no specifications have been defined for the grid feed-in of self-generated electricity. Grid operators fear that the electricity grids could collapse under the strain. For ECAMI S.A., a company that plans and builds renewable energy systems, SMA Data Manager M powered by ennexOS was just what it needed. 

Nicaragua’s largest — and only — brewery, Compañía Cervercera de Nicaragua (CCN) in the country’s capital, Managua, has been using solar power since 2017. ECAMI S.A. installed solar modules on its premises and covered parking lots. Coupled with 36 Sunny Tripower 30000TL string inverters, they produce roughly 1,152.00 kWp of clean solar power for brewing beer. CCN obtains the rest of its electricity from the medium-voltage grid. Over the course of a week, this amounts to an extra 2.5 MW or so each day. At weekends, consumption is just below the maximum generation output of 700 to 900 kW.

Self-consumption cuts energy costs

Katharina Grosse, José Luis Mendieta Galo and Jairo Velasquez are project engineers at ECAMI, and they know all about the requirements of Nicaraguan companies when it comes to energy management. They build typical self-consumption systems for manufacturing companies and grocery stores. After all, there is no shortage of sunshine in Nicaragua. Free, self-generated electricity is a great way for companies to avoid paying the country’s relatively high electricity prices and to achieve significant reductions in their energy costs.

No grid feed-in for even a millisecond

The brewery, which has been producing a wide variety of beers for Nicaragua since 1926, is another company that has achieved considerable savings on energy costs thanks to its PV system. It could improve its financial gain yet further if it could export its surplus electricity to the grid in return for a feed-in tariff. But that is not allowed. According to the strict regulations, no electricity is allowed to be fed into the grid – not even for a millisecond.

Data Manager M enables devices to work together

Commissioning of the system

To ensure zero feed-in, the ECAMI project engineers had initially envisaged a solution that proved unreliable in practice owing to the lack of compatibility between the separate devices. This problem is now solved thanks to SMA Data Manager M, which features interfaces that enable it to work with the medium-voltage meter used as well as the lower-voltage energy meter installed (Janitza 604). It ensures dynamic curtailment of the PV system and zero export. Not only that, but with the monitoring functions of the new Sunny Portal powered by ennexOS, it also provides evidence of zero feed-in for the grid operator and takes care of monitoring at partial system level, verifying performance for the customer.

Thinking about future functions

It is not only the current functions of SMA Data Manager that are of interest to project engineers at ECAMI as well as the operators of the brewery, but also those that will be available in the future. That is because the new ennexOS energy management platform from SMA, which also provides the basis on which Data Manager works, is a modular system, enabling it to be expanded alongside the functions of the devices based on it. In addition to zero export, the ECAMI project engineers are thinking about peak load shaving at manufacturing companies because electricity prices in Nicaragua are very high and billed monthly. Furthermore, integrating SMA storage solutions provides companies with an attractive opportunity to save on energy costs, while Katharina, José and Jairo see a lot of potential in the integration of charging stations for electric vehicles in a company’s energy system.

For other customers like grocery stores, integrating refrigeration systems such as those from Danfoss is also very important. That is why the trio is already looking ahead to additional projects that could benefit from the functions of SMA Data Manager M.

Find all articles about the SMA energy-management platform ennexOS here.

Left to right: Norman Solorzano, Jose L. Mendieta, Katharina Grosse, Jairo Velasquez