An almost 100 percent turnkey solution that provides benefits beyond renewable production and Peaker capability. Wayne Gerdes – CleanMPG – Jan. 15, 2021 As one of the National Renewable Energy Labs (NREL) top stories from 2020, Solar storage is quickly becoming economically viable and in some regions of the U.S. and world, it provides superior grid load balancing and blackout restart capability than any current AC generation solution. When the sun doesn’t shine, and the wind doesn’t blow, large scale renewable energy production is essentially stuck in park. New methods for energy storage allowing power when it’s needed are now not just imaginable but are being deployed at a record pace. Declining costs in the price of lithium-ion batteries, down 80% over the past five years, is now enabling the integration of storage into solar power systems. Tesla’s Powerwall micro grid solar and Li-Ion storage technology for the individual homeowner comes to mind. On a regional or city utility scale, there are numerous renewable power production projects currently being designed, built or going online that will move the entire country, let alone world, to a whole new level of clean energy. All our meant to reduce or eliminate the need for fossil fuel consumption and GHG emissions to meet our almost unsatiable need for energy. Today, nearly 18% of all electricity produced in the United States comes from renewable energy sources including hydropower and wind. As homeowners, communities, and entire states push toward higher percentages of renewable energy production, there’s no doubt massive and inexpensive power storage will play an important role. Compared with 2019, the US experienced an approximately 90% increase in the amount of storage deployed in 2020. By 2024, that number is expected to top 5.4 gigawatts. The market value is forecast to increase from $720 million today to $5.1 billion in 2024. Driving such growth is an increased focus on adding renewable energy sources and now renewable energy storage to the nation’s grid. The National Renewable Energy Laboratory (NREL) was plotting a path to 20 percent of the nation’s energy supply to come from renewable sources. Now, they’re aiming much higher. NREL’s Renewable Electricity Futures Study estimated that 120 GW of storage would be needed across the continental United States by 2050 to reach a future where 80 percent of electricity consumed will come from renewable resources. The country currently has 22 GWs of storage from pumped hydropower, and another GW in batteries which is increasing logarithmically. AES Lawa’i Solar 28 MW DC PV + 100 MWh, 5-hour Battery Energy Storage System Case Study In December 2018, AES made history when it inaugurated a 28 MW PV + 100 MWh five-hour duration BESS Lāwaʻi Solar and Energy Storage project, the world’s largest operational solar-plus-storage system, in Kaua’i, Hawaii. AES designed the unique DC-coupled solution to fully integrate PV and storage as a single power plant. While many other systems, especially AC-coupled systems, coexist but are not tied together, this PV Peaker Plant fully combines and integrates the components into a singular harmonious system at a never-before-seen scale. The new PV Peaker will deliver roughly 11 percent of Kaua’i’s power from a smallish 150-acre footprint site, making the island more than 50 percent powered by renewables, and will help Hawaii reach its goal of reaching 100 percent renewable energy by 2045. AES’ PV Peaker Plant promises to replace traditional generation – diesel fueled electrical generation in the case of Kauai, in a more flexible solution designed for a modernizing grid. Because fossil fuels must be shipped onto the island, Kaua’i has some of the nation’s highest electricity prices in the U.S. Leveraging the solar resource for the evening demand peak on Kaua’i allows the utility to cut back on fossil fuel costs; the PV Peaker Plant batteries can keep delivering firm power for 5 hours after the sun goes down. Not only are the energy costs from the PV Peaker Plant below the cost of fossil fuel to power the island, they often beat the cost of the fuel alone! At 44% solar in 2018, the island needed enough storage to provide consistent, reliable peak power. But batteries alone aren’t the answer since they can’t dispatch energy fully during the day when they need to be charging. KIUC needed a renewable energy system that would provide power when solar panels are dormant, and demand is peaking. To solve each of these challenges, AES designed the PV Peaker Plant to fully integrate solar and storage as a power plant. The new system allows solar to occupy the role that thermal generation has played in varying output to meet peak demand. It’s expected to deliver energy principally during early morning (6AM-9AM) and evening (4PM-10PM) hours. The PV Peaker Plant supports three vital scenarios in power distribution: It allows for solar generation to supply the grid while charging the battery system and dynamically altering the allocation as demand changes It dispatches power stored in the Battery Energy Storage System (BESS) to the grid during evening and morning peak demand periods It can dispatch solar and battery power simultaneously to answer spikes in demand or black start the grid altogether after a system-wide outage To lower the cost of operation and transmit more energy reliably, each power block is on a DC-DC backplane, sharing inverters and transformers. AES owns and operates the plant on behalf of KIUC with power provided to the utility at $0.11/kWh. By comparison, the EIA calculates that in 2019, U.S. Nuclear costs $0.237/kWh, Coal costs$0.367/kWh, Hydro costs $0.108/kWh and Gas turbine costs $0.283/kWh. The PV Peaker Plant also converts energy dramatically faster than the traditional SCADA systems used for plant management. Whereas traditional SCADA systems have a one-second response time, the PV Peaker Plant controls coordinate hundreds of devices for a system-level response within 50 milliseconds! Within normal operations, the batteries can charge without pulling any energy from the grid. In addition, the unique design allows PV to flow onto the grid through the inverter, or directly to the BESS for storage. It also enables a combination of PV and stored energy to flow simultaneously through the inverter and onto the grid. This DC-coupled solution makes solar a dispatchable and controllable resource and does this more efficiently than a traditional AC-coupled system. What’s more, the DC-coupled architecture saves on redundant equipment such as inverters and transformers while increasing overall roundtrip efficiency compared to an AC-coupled system. Because it requires half as many inverters and transformers, the PV Peaker Plant is faster to respond to demand peaks, more efficient and more flexible than a standard AC-coupled system. As such, the model sets a new standard for solar-saturated markets that need to time-shift most of the solar generation. The PV Peaker Plant is now a blueprint on how to provide flexible, renewable generation in markets struggling with increasing cost-effective renewables penetration that not only tie into the existing grid but modernize it. This pioneering project has already inspired a wave of followers, including AES’ 19.3 MW solar + 70 MWh battery energy storage facility currently under construction on leased land from the U.S. Department of Defense within the Pacific Missile Range Facility – Barking Sands (PMRF) Naval Base. Hawaiian Electric which delivers power to over 95 percent of Hawaii residents on all other islands aside from Kaua’i, recently completed the procurement process for the largest infusion of renewable energy in state history. Hawaiian Electric selected a total of seven projects that will add a combined 262 MWs of solar energy and more than 1 GWh of energy storage on the islands of Oahu, Maui and the Big Island. The projects will nearly double the entire country’s current energy storage capacity, which stands at 1.4 GW. By combining solar power with battery-based energy storage, intermittent renewable generation can be converted into reliable power. The fully integrated Lāwaʿi project will eliminate the use of 3.7 million gallons of diesel annually while supporting three vital scenarios in power. Declining costs of solar, and use cases such as this project, will make similar systems the smartest choice to leverage abundant energy from renewables in many other parts of the world. The AES PV Peaker Plant project increases grid reliability while being the most cost-effective solution. It has paved the way for subsequent projects and indicates that solar-plus-storage is not only the environmentally-choice but is a necessary and reliable, cost-competitive solution to attaining a 100% renewable energy future.