The Sun Doesn’t Have to Shine all the Time to Provide Power

February 26, 2019

Solar power after sunset is not only possible, it’s essential to a clean-energy future. The combination of solar + storage increases grid stability, enhances distribution networks and helps bring power to remote places. Batteries charge by day when sunshine is abundant and release energy when people need it most, including peak hours after dark when solar panels are no longer producing power.

Essentially, energy storage aligns renewable production with peak demand. Solar + storage provides flexible capacity by both absorbing over-generation midday and discharging it during the evening hours.  Releasing solar when it has traditionally been unavailable will provide continuous access to a cleaner, more reliable energy mix.

Integrating solar power with battery-based storage also increases solar power’s value. It forms what we call, “firm renewables.” That is, the combination creates predictable blocks of renewable energy that can be bid into the energy market just as traditional methods of generation are.

The need to store energy has never been more critical. This conviction is evident in three recent groundbreaking projects AES has launched with partners in the U.S. and Asia.

Expanding battery-storage in the  U.S.

We’re harnessing the abundant Arizona sunshine to provide critical summer peaking capacity with Arizona Public Service (APS). As Arizona’s largest and longest-serving electric company, APS is charting the course to a clean-energy future in this state. Energy affordability and reliability for its customers are the utilities’ top priorities.

APS started meeting these goals and addressing changing energy needs already through a previous 50-MW battery storage project. APS’s battery storage projects add up to more than what the entire U.S. electricity industry installed in 2018, and it’s continuing to grow its position. Now, AES is partnering with APS to deliver a 100 megawatt (MW) 4-hour duration system battery-based energy storage system.

This will help serve the state’s expanding population of citizens who are increasingly seeking clean energy options. In addition to peaking capacity, the project, owned and operated by AES, will offer operational flexibility, resulting in the most efficient use of renewable energy. As a result, costs and emissions will be lowered and reliability improved. 

The largest solar + storage project in the world

We’re helping Hawaii become 100% renewable. In partnership with Kauaʻi Island Utility Cooperative (KIUC), we launched the Lāwa’i Solar and Energy Storage Project located on Kauaʻi’s south shore. It’s the largest operational solar + storage project in the world.

The Kaua’i project is also the world’s first solar powered peaking plant and supports three critical renewable power distribution scenarios.

  • It allows for solar generation to supply the grid while charging the battery system.
  • It dispatches power stored in the battery system to the grid during peak demand periods.
  • It can dispatch solar and battery power simultaneously to answer spikes in demand in addition to supporting the grid through provision of ancillary services.

The project consists of 28 megawatt (MW) solar photovoltaic (PV) and a 100 MWh five-hour duration energy storage system. It provides peak capacity from the sun and allows the island to power itself with clean, renewable energy more than half of the time at a fraction of the previous cost.

AES is currently constructing an additional 19.3 MW solar + 70 MWh battery energy storage facility for KIUC located on leased land from the U.S. Department of Defense within the Pacific Missile Range Facility – Barking Sands (PMRF) Naval Base. We were also recently selected by the Hawaiian Electric Companies for two of its seven solar-plus-storage projects in Hawai’i, representing the largest addition of renewable energy in the state’s history.

The first grid-scale battery-based energy storage solution in Asia

We see the potential for energy storage to revolutionize the grid in India and help the country fulfill its vision for 225 GW of renewables by 2022. Together with Mitsubishi, we launched the 10 MW / 10 MWh Delhi Battery-based Energy Storage System (BESS) for Tata Power-DDL. It’s the first grid-scale battery-based energy storage solution in India and largest in South Asia. Clean, unbreakable energy will boost efficiency, resiliency and reliability for more than 2 million customers in the Delhi region.

Energy storage can also greatly impact India’s commercial and industrial sectors by powering can’t-fail manufacturing operations and enabling better onsite generation. In remote areas of India that lack access to electricity today, energy storage can be paired with renewable generation to extend safe, affordable power to these communities.

Transmission and distribution network operators can also use energy storage to manage the variability of solar and wind resources and reduce congestion on the region’s transmission system.

Solar + storage costs less all around

We’ve reached a point when energy storage is a more cost-effective alternative to traditional single-use infrastructure, and it is more environmentally friendly. It offers flexible capacity to meet peak demand, firm renewable generation and is a transmission asset. 

The various uses and range of geographic locations mentioned here demonstrate the ability for solar + storage to have a positive global impact. AES will continue to partner with leading companies on technological innovation that can help us deliver on today’s changing energy needs.

Andrés Gluski

AES President and CEO