Negative prices push Europe's solar fleet into storage: the financing wave in Spain, Italy and beyond

Spain recorded 397 hours of negative day-ahead prices in the first quarter of 2026, against just 48 in the same period a year earlier. Solar capture rates have fallen from roughly 83% in spring 2023 to around 54% in spring 2026. That arithmetic — not policy — is now the main driver of Europe's storage build-out, and it has produced a run of landmark financings across the continent.

Spain: from hybrid PPAs to the first standalone BESS financing

Two milestones frame the Spanish market. In May 2026, investor Bruc secured a €370 million green loan from Banco Santander and Banco Sabadell for 659 MW of solar with 1.6 GWh of integrated storage in Aragon, all operating under PPAs with leading offtakers, with commercial operation expected in 2027. In July 2026, Santander and SMBC provided a €100 million senior non-recourse financing to Grenergy Renovables for its 155 MW / 620 MWh battery cluster in Oviedo, Asturias — the first standalone BESS project financing in Spain, structured as an eight-year mini-perm and backed by a 10-year structured PPA with a leading European utility from January 2028.

Earlier, IPP Zelestra signed what it calls the first PPA enabling hybridisation of an operating solar plant with storage in Spain — adding a 160 MWh BESS to its 50 MW Pizarroso plant, with EDP remaining offtaker. IPP BNZ, owned by Nuveen Infrastructure, plans 850 MW of BESS across Spain, Italy and Portugal, starting with 530 MW through 2026–27.

Italy and the multi-country portfolio model

Italy ranked third in Europe by BESS deal count in 2025 with 12 transactions, helped by the conclusion of the MACSE capacity auction, which allocated 10 GWh of long-term storage revenue contracts and unlocked a wave of final investment decisions. The European Investment Bank's €507 million Project Sophocles — signed with Natixis CIB and Sunprime in March 2026, with up to €271 million from the EIB itself — will fund roughly 290 MWp of solar and 350 MW of BESS through 2028.

The maturity signal is Sonnedix's €730 million refinancing and construction facility, closed in August 2026 with nine lenders including Santander CIB, ING and UniCredit, covering approximately 540 MW of solar and two BESS projects across France, Italy, Portugal and Spain — with Italy the heaviest weighted at over 350 MW. Lenders are now underwriting multi-country hybrid portfolios in a single package.

Where else the money is going

• Poland: the capacity market has contracted roughly 5.1 GW of deliverable BESS (about 11 GW of physical capacity); R.Power closed a €64 million package with Siemens Financial Services and Erste Group for its Jedwabno project — reportedly the largest utility-scale BESS project financing in Poland to date;
• Romania: Alfi Green Energy Fund and Kraftfeld Energy closed €90 million with Raiffeisen Bank International for a 126 MW solar, 200 MWh BESS joint venture targeting operations from early 2027;
• Belgium: Engie and NHOA's 320 MWh Drogenbos BESS secured a 15-year capacity remuneration contract from November 2027.

Europe's lesson for emerging markets is the mirror image of their own: mature markets monetise scarcity of flexibility; emerging markets monetise scarcity of firm capacity. Both routes end in the same place — storage as a financeable asset class with its own contracted revenue logic.