For non-technical people the idea of running an own mobile network may feel like swimming in cold water. Not nice. If that is the case, an own mobile network with an own off-grid solar plant may feel like swimming in cold water with a heavy backpack.
It does not have to be that way.
Frequent power cuts are a norm in large parts of the world, especially in Africa. Combined with soaring energy prices and green transition, diesel gulping generators also turn unattractive. In large parts of the world, off-grid solar is rapidly becoming the preferred solution for powering private mobile networks.
At Poutanet we have many ongoing engagements in the emerging markets. Regularly, customers flag issues with energy access. Sites are off-grid or connected to an intermittent poor grid. For being able to help, we decided to take the bold step and power our test network with appliances used at the site using off-grid solar. This required close cooperation with a smart off-grid specialist Karugrid.
The smart energy controller provided by Karugrid offers unique capabilities for prioritising the various energy uses. In our project, we developed the solution to support a model where the customer (in this case we) can themselves manage and control different loads. For example, we might decide that, for a given time, the AC powered water heater has higher priority than the communications equipment.
“Opportunities to adjust the use of electricity in a site-specific manner is important”, says CEO Antti Pinomaa of Karugrid. “As sunshine is not fully predictable, the dimensioning of off-grid solar electricity systems is done with slight overhead. Therefore, during ordinary days, there is some overhead, which enables additional uses for electricity. The API-enabled access to Karugrid smart energy controller makes it possible for the base station owner to flexibly adjust priorities for external electricity usage. Overhead electricity can be used for various purposes in a dynamic way maximising the benefits from the investment. With the Karugrid smart monitoring and control solution, there is no need to worry about the lack of electricity for the prioritised main purpose.”
Such modularity of the solution delivers additional benefits. The off-grid power system can serve a single base station or it can be extended to provide energy to the hosting house (solar home system). With some stretching of limits, it can even be extended to provide energy to half-a-dozen nearby houses acting as a small local micro-grid creating smart energy communities - with reliable priority for the connectivity service offered by the base station. All these variations come up regularly in our discussions with African partners.
For these reasons we selected the Karugrid solution and built a reference system in Rajamäki. For us it also serves as a “living lab” for learning about real-life energy solutions, gaining know-how and integrating the power system with our own network management practices. This experience helps us to safely guide our customers on stable connectivity with sustainable energy provisioning. On top of all this, as an important side effect, our Rajamäki mobile network is now a truly green site - except for the winter months when there is not enough sunlight in Finland that would motivate brushing off snow from the solar panels.
