Slovenia’s transmission system operator ELES is becoming an operational member of pan-European balancing energy exchange platform MARI. It is the final step in the country’s integration into the EU’s electricity market.
After joining the Platform for the International Coordination of Automated Frequency Restoration and Stable System Operation (PICASSO) at the beginning of this month, Slovenia’s transmission system operator ELES is today also accessing MARI (Manually Activated Reserves Initiative), Naš stik reported. It is the final step in the country’s integration into the European Union’s joint electricity market.
Both platforms are for the cross-border exchange of balancing energy. PICASSO covers automatic frequency restoration reserve, aFRR, the second line of defense against grid imbalance. MARI is for manual frequency restoration reserve – mFRR.
It is the tertiary regulation segment, activated when frequency containment reserve (FCR) and aFRR can’t handle the imbalance.
ELES is responsible for keeping electricity production in Slovenia equal to consumption. It takes on lease 190 MW of mFRR in the positive direction and 92 MW on the negative side.
Cross-exchange platforms facilitate bid ranking
Pan-European systems PICASSO and MARI operate on the same principle, with an algorithm ranking bids to be activated in the determined order. The pricing system is marginal, like in the spot power market, so everyone gets compensated at the highest rate, awarded to the last participant that was activated.
The difference is that in MARI the system operator requests activation, while in PICASSO it goes automatically.
Costs within MARI may annul savings from PICASSO
While PICASSO could bring some savings, expectations from the other system are mixed, the article adds. Within MARI, ELES can’t buy balancing energy on the intraday market anymore, where the prices are generally lower than for aFRR and rFRR, according to the news outlet, which operates under Slovenia’s transmission system operator.
Bulgaria was already an operational member of MARI, but alone in an island mode until one of its neighbors joins
“If we have previously activated the tertiary reserve once a month, we will now have to activate it several times a day,” said the state-owned company’s Deputy Director of System Operations Aleš Donko.
In the region that Balkan Green Energy News covers, Bulgaria was the first one that became an operating member of MARI, in February. But Electricity System Operator (ESO), its TSO, works in an island mode, as none of its neighbors have yet accessed the platform.
