ARIZONA PUBLIC SERVICE ANNOUNCES ONE OF THE LARGEST SOLAR BATTERY PROJECTS IN THE US
Arizona Public Service, the largest electric utility in Arizona, announced Thursday morning that it will add 850 MW of battery storage and 100 MW of solar generation by 2025, making it one of the largest battery projects in the country. The initiative includes both future projects as well as facilities already in development.
First, APS will add 200 MW of batteries to pre-existing APS-owned solar farms throughout the state. APS has partnered with developer Invenergy on the eight facilities, six of which will be online in 2020, with the remaining two by 2021.
APS also plans to add 500 MW of new energy storage, as both stand-alone facilities and paired with solar farms, by 2025. The first project will be a 100 MW solar and storage facility. APS plans to send out request for proposals this summer.
APS will use 150 MW of batteries to meet peak demand
APS will use 150 MW of the solar storage to meet late-afternoon peak demand, a growing challenge for utilities as more and more homeowners and businesses install solar on their roofs.
Before solar panels were so ubiquitous, utilities had the whole ‘peak demand’ thing pretty worked out. As people got home from work and started using their appliances, TVs, and air conditioning, utilities quickly ramped up energy production of their short-term-use ‘peaker plants’, typically fueled by natural gas.
As more homeowners and businesses install solar though, this demand spike is becoming more pronounced, as solar produces the most electricity mid-day. As more solar energy is produced, electricity demand subsequently decreases at that same time, since homeowners aren’t having to buy electricity to cover their needs.
Take a look at the graph below of electricity demand in solar-heavy California. You’ll see that demand is lowest around mid-day, as solar installations are pumping out free electricity, powering people’s homes. However, as night comes and the workday comes to an end, all the solar panels suddenly stop producing electricity at the same time everyone gets home, causing a massive increase in electricity demand that utilities must quickly meet. (The utility world calls this issue the ‘Duck Curve’.)