Switzerland and Chile have authorised a second battery energy storage system (Bess) project under Article 6.2 of the Paris Agreement in the South American country, which will enable the reduction of around 1.4mn t of CO2 equivalent (CO2e) until 2030, the countries said this week.
The project consists of the 220MW Arena Bess and 300MW Patache Bess standalone grid-connected units installed in the north of the country, both developed by Danish fund manager Copenhagen Infrastructure Partners.
Construction of Arena Bess is nearing completion and Patache Bess is at a "late development stage", according to Swiss government-mandated carbon project developer the Klik Foundation.
The Bess sites will help integrate more photovoltaic power to the grid, storing it during daytime and discharging it at night, thereby displacing fossil fuel-fired generation and reducing greenhouse gas (GHG) emissions.
Over 70pc of Chile's power generation comes from renewables and the country aims to increase the share beyond 90pc by 2030, with the phasing out of coal-fired power generation a central part of its nationally determined contribution (NDC) climate plan under the Paris agreement.
Chile has in recent years seen a strong rise in photovoltaic power curtailment, according to the project documentation, and the country included Bess in its list of prioritised activities under Article 6, expecting the GHG emissions mitigation potential of Bess to go beyond its NDC.
Switzerland is also financing an earlier 228MW Bess project in Chile connected to a photovoltaic plant under Article 6.2.
Bess technology still faces implementation barriers such as high capital expenditure and technological risks, despite the large fall in costs for lithium-ion Bess in recent years, Klik said.
Article 6.2 allows countries to generate and trade internationally transferred mitigation outcomes (Itmos), in the case of this latest project enabling GHG savings in Chile to count towards Switzerland's NDC — approximately 1.4mn Itmos.
These projects are viewed as additional — economically unviable without the Itmos — and the emissions reductions sold towards the buyer countries' NDCs would be reflected in Chile's GHG accounting — key features of Article 6 carbon markets.
Both sites come with grid-forming components. Under Chile's rules for carbon market finance, a grid-forming Bess is entitled to 100pc finance through Itmos, regardless of its storage capacity.
A total of 66,000 Itmos are listed in Switzerland's registry so far, most of which have come from an electric bus programme in Bangkok, Thailand.
Klik early this week underlined the need for a 1bn Swiss franc ($1.2bn) "risk buffer" to hedge against potential delivery failures from its international carbon offsetting activities.
Switzerland's government has said that for the period after 2030, it will consider buying offsetting credits generated under the more formalised Paris Agreement crediting mechanism (Pacm) under Article 6.4 of the Paris deal, once the system is operational and provided Switzerland's CO2 law has been amended to provide the legal basis. A draft law is expected to be put to consultation this autumn, the ministry said this week.
The ministry stressed that Switzerland will not buy Pacm credits that have transitioned from the market's predecessor, the clean development mechanism.
And there will be no "automatism" in recognising Pacm credits, the ministry said, although the government does not plan to "subject every application to the same time-consuming verification process as that applied to projects under [Article 6.2]".

