What happens when the sun goes down? The infernal question is no more.
Engie has been notified by the Power Authority of Guam that it was the lowest bidder and has won a contract to construct two solar power plants totaling 50 MWdc with approximately 300 megawatt-hours of energy storage. Significantly, the system is designed to deliver 100% of the electricity after the sun goes down. Engie noted that it will now begin work on the details of the twenty year power purchase agreement (PPA).
Engie says that the Samsung SDI batteries which it has chosen for the energy storage solution will be able to deliver electricity for up to seven hours. The 300 MWh and 50 MWdc values weren’t coupled with the energy storage inverter capacity or AC solar sizing. If the project were to deliver the full 300 MWh of electricity over the course of seven hours, the minimum size of the energy storage inverter would be just over 42 MW. If the solar inverter (MWac) were similarly sized, it’d be a DC:AC ratio of 1.16.
The projects are expected to come online in July 2022, and will delivery 85 GWh/year of electricity – a 19.4% DC capacity factor.
A 500 page project procurement requirement document (pdf) was made available for review in late 2018. The projects were proposed to be built in the specific locations noted in the above image, and connecting to a new substation being built.
The qualitative scoring system used to judge bids is located here (xls). Higher accuracy images of the sites are located here (pdf).
Phase II of the program (pdf) ended with two 25 year PPAs being signed with Hanwha Energy Corporation for 30 MW solar projects that will deliver roughly 144 GWh/year of electricity in total for 6.245¢/kWh and 6.599¢/kWh.
While there are plenty of solar+storage projects that run sites 24-7-365, this project is significant in that its among the largest energy storage systems announced globally, and the solar power is to be delivered 100% at night. Eventually, Guam Public Utility Commission will post the power purchase agreement (prior signed documents are on the website) and its prices, on their website.
With that, we will be given a new pricing perspective to consider in our models – what does 100% delivered at night solar power cost? The large majority of our solar pricing is daytime priced electricity – delivered 100% at time of generation. Recently, the Eland project in Los Angeles (above image) gave us some insight into our new pricing considerations. In that project, we saw solar electricity pricing of 1.997¢ delivered at time of generation, add 1.3¢/kWh for 200 MW / 800 MWh worth of energy storage, and another 0.667¢/kWh when we expanded to 300 MW / 1,200 MWh to deliver the excess electricity during the evening peak period.
A lot of unknowns still, but we’re inching close to 24-7 solar.
This content is protected by copyright and may not be reused. If you want to cooperate with us and would like to reuse some of our content, please contact: editors@pv-magazine.com.
At the SPI conference in Utah, the announcements for energy storage seems to keep coming. NEC has signed a contract with AMBRI to use the molten metal technology in utility scale energy storage systems. Kyocera just announced a partnership with 24M using their semi-solid lithium ion battery technology for residential energy storage systems in Japan by 2020. 24M is the one who claims with utility scale energy storage systems of 1GW or greater, the cost per watt is around $1/Watt. Right now China is saying new technology like bi-facial panels can be from $0.28 to $0.35 a watt for large scale manufacturing run of solar panels. Would it then be possible to create a 1GW peak solar PV farm, with 1GW of energy storage for $1.5 to $2 billion dollars? Now how can nuclear and natural gas fired plants compete with that? Amortization in a decade or less, rather than the usual amortization in (decades).
John Weaver, thank you for your coverage of the SPI event. It has convinced me that perhaps for some folks, it would be wise to look for product providers in the commercial solar PV and energy storage sector for home use. On larger solar PV systems, it might make sense to go with a commercial energy storage system with three phase and get their own three phase to 240VAC Faraday shielded transformer.
happy to report