Incentivising the deployment of energy storage infrastructure and curtailing wind farms at times when high levels of generation coincide with low electricity demand are amongst options being considered by Poland's electricity network operator, PSE Operator, as it prepares for the challenge of grid connecting offshore wind projects.
Just two of a longer list of offshore wind projects granted preliminary rights to proceed by the Polish government have been awarded grid connection commitments.
In August, Kulczyk Holding's 1.2GW Baltyk Srodkowy III project won a connection promise from PSE Operator, while at the end of last month PGE Energia Odnawialna (PGE EO) was given a 1GW connection commitment.
This compares to about 31GW of planned onshore capacity for which PSE Operator has either signed a grid connection contract or issued a grid connection promise.
Connecting Baltyk Srodkowy III will not be difficult, according to Henryk Majchrzak, president of PSE Operator. It will cost approximately PLN200m (€48.7m) to increase cable temperature and capacity. But the cost of connecting PGE EO's project will be much higher, up to PLN1.5bn “because we will have to build lines not foreseen in our investment plan to 2025,” said Majchrzak.
With a substantial offshore wind sector apparently on the horizon, PSE Operator is exploring how it can integrate offshore-generated electricity. Some offshore capacity is expected to be grid connected in place of planned onshore wind capacity that will not – for a variety of reasons - end up being built. Indeed, some argue that at least half of the more than 30GW of planned onshore capacity will not be built.
Between now and 2025, PSE Operator is planning a grid expansion and strengthening programme to include 4,600km of new 400KV lines, 17 new elecricity substations and the modernisation of 2,500km of existing 200KV and 400KV lines.
“But it is not enough to build new lines,” acknowledged Majchrzak. National electricity demand and conventional power plant output mean the Poland's electricity network will only be able to absorb about 6.2GW of wind-generated electricity at night.
How can such a low level of integration be overcome? The TSO believes a policy of wind farm curtailment and incentivising energy storage are two partial solutions.
“We could connect more wind farms to the system if we had the possibility to cut them out without penalties once they reach 70% of nominal output during lower demand periods,” said Majchrzak. He added: “This move would bring almost no negative financial impact on wind farms, but would dramatically increase their presence in the system from 6.2 GW to 8.9GW until 2020.”
Energy storage is also in PSE Operator's sights. It is propsing a new provision to Poland's energy law, one that would prioritise grid connections for wind farm projects that include an energy storage element.