Greece faces solar energy surplus

"You shouldn't let them grow too high to avoid harming the performance of the panels," the fifty-year-old explained to AFP, while wiping his sweaty forehead.

As in other agricultural regions of Greece, the fields around Kastron Viotias, 110 km northwest of Athens, have been transformed into solar farms over the past fifteen years.

An approach deployed in other agricultural regions of Greece as part of a policy of developing renewable energies supported by the European Union.

In 2023, Greek Prime Minister Kyriakos Mitsotakis predicted that Greece would "soon produce 80% of its electricity needs from renewable energy."

But the reality turns out to be more complex.

A Mediterranean country with high annual sunshine, Greece currently has 16 gigawatts of renewable energy, including nearly 10 GW from solar power.

In 2024, €1,6 billion was invested in new photovoltaic projects across the country, increasing the total capacity by 2,5 GW, according to the Hellenic Association of Photovoltaic Companies (HELAPCO).

Solar's growth is similar to that in other European countries where it has supplanted coal, according to climate think tank Ember, which estimates that renewables now account for nearly half of European electricity generation.

Greece is doing even slightly better, with 55% of its annual electricity consumption coming from renewable sources last year, and solar power accounting for around 23%, according to the Greek solar energy producers' association SPEF.

However, the sector is reaching saturation point due to the country's small size, limited infrastructure and the delay in developing energy storage capacity, explains chemical engineer and president of SPEF, Stelios Loumakis.

Saturation

Greece has approved too many photovoltaic projects over the past five years and the market is saturated, often leading to "serious overproduction" on sunny days, the scientist explains.

In May, the electricity operator DEI had to repeatedly order thousands of medium-sized producers to turn off their units during the sunniest hours of the day to avoid a power outage.

"The challenge is to find a balance between supply and demand. If we don't do it right, it could cause a power outage," warns Nikos Mantzaris, a partner at the Green Tank organization.

In April, a massive blackout of unknown origin paralyzed Spain and Portugal. Madrid reported that two major power fluctuations had been recorded in the half-hour before the grid collapsed, but did not attribute the outage to renewable energy sources.

To manage the surplus, Greece is developing a battery storage system.

But catching up with its solar electricity production will take years.

"The next three years will be crucial," says Stelios Psomas, advisor to HELAPCO.

"Managing a significant percentage of renewable energy—especially solar—requires significant flexibility and storage solutions," notes Francesca Andreolli, a researcher at the think tank ECCO, in Italy, a country facing the same challenge.

"Battery capacity has proven to be a structural necessity to absorb excess renewable energy and release it when demand increases," she explains.

Lucrative solar

Mimis Tsakanikas, a 51-year-old farmer in Kastro, acknowledges that solar has been beneficial for his family.

Installed in 2012 for 210.000 euros, his photovoltaic farm generates an annual income of at least 55.000 euros, much more than growing vegetables and watermelons, he assures.

However, he is concerned about a change in the local microclimate since the proliferation of solar installations.

Residents have already noticed temperature increases of up to 4°C.

"The microclimate has definitely changed; we haven't seen frost for two years," he laments.

"In five years, we will be growing bananas here, like in Crete," the southern island hit by high temperatures, he says ironically.