O2 Telefónica Germany said it has built a self-sufficient off-grid radio tower equipped with 5G technology.

The telco claims it's an industry first, with its site in Kirtorf, in the Hesse region of Germany.

According to the operator, the 50-meter-high mast has been erected to close a white spot.

Previously a signal dead zone, customers on the telco's network can now make calls with 2G (GSM), 4G (LTE), and directly with the modern 5G standard.

O2 Telefónica Germany notes that solar cells and a 'highly efficient' fuel cell generate sustainable electricity on-site as the facility does not have a conventional electricity connection.

The location of the tower, in the middle of agricultural and forestry land, means there is no power supply for miles. Laying a new power line would exceed the cost of the site.

To support the site, O2 Telefónica said that photovoltaic modules have been installed next to the radio tower as the primary energy supply for the system.

Excess electricity generated during the day is then stored in lithium batteries to ensure round-the-clock operation.

An intelligent software system automatically switches between the energy sources as required.

O2 Telefónica claims the new concept site can deliver savings of more than 13,000KWh per year compared to a mobile phone tower powered by conventional electricity.

"Our new site in Kirtorf is a prime example of efficient mobile communications coverage in rural areas: a site without electricity, but with plenty of energy and 5G for our customers," said Mallik Rao, chief technology and information officer of O2 Telefónica.

"The new concept shows how we can expand in an economically sensible way while protecting the ecosystem."

He added: "We want to drive forward digitalization and provide everyone with mobile communications. To this end, we are closing the last white spots in the country, even if the development of the mobile infrastructure here is sometimes challenging."

Though Telefónica is claiming an industry first, a number of telcos and OEM suppliers have been working towards on-site power generation at cell tower locations, with multiple trials in Germany.

In 2022, Deutsche Telekom and Ericsson completed a trial in Germany showing cell towers can be powered with renewable energy generated on-site. The German telco and Swedish OEM conducted the trial at a live cell tower site in Germany where it was able to operate entirely from wind and solar energy generated by on-site panels and turbines.

Vodafone, Vantage Towers, Latvian telco LMT, and Telstra have also invested in on-site renewables at tower sites. Ericsson last year set up a 5G site in Texas that is powered by solar energy.

Also this week, O2 Telefónica signed a new Power Purchase Agreement (PPA) to procure wind energy in Germany.