Addressing Grid Congestion for U.S. Solar Projects

Grid-enhancing technologies (GETs) have long been treated as “pilot projects.” That’s no longer true. Across the U.S., GETs are moving into real-world deployment—quietly adding capacity, lowering costs, and improving reliability without pouring a single yard of new concrete. For example: * In California, Pacific Gas and Electric Company has moved beyond concept and into field deployment of dynamic line rating and advanced monitoring across multiple transmission corridors—aimed explicitly at unlocking capacity and reducing congestion. * Nationally, utilities and grid operators are scaling GETs like dynamic line ratings, topology optimization, and power flow control because they can deliver capacity faster and cheaper than new transmission. * Real-world modeling and deployments show GETs can increase transfer capacity by up to ~40% on existing lines and even pay for themselves in months through reduced congestion and lower system costs. * Even simple weather-informed line ratings can boost capacity significantly—sometimes double-digit percentage gains—by using real operating conditions instead of conservative assumptions. And the big number: 👉 GETs could unlock 80+ GW of incremental capacity in the U.S. grid—without waiting a decade for new wires. So what’s the bottleneck? Not technology. Not cost. Policy. Right now, most regulatory frameworks treat GETs as pilots, not core infrastructure. As we know they favor capital build over operational optimization, and they lack clear cost-recovery pathways. If we’re serious about affordability, PUCs should act now: 1. Require GETs evaluation in every transmission plan 2. Approve OPEX recovery and performance-based incentives 3. Treat GETs as “first resort” before new build 4. Set deployment targets tied to congestion relief and ratepayer savings Bottom line: We don’t have a technology gap—we have a deployment gap. And closing it may be the fastest way to: * lower bills * integrate new generation * and meet surging demand from data centers and electrification GETs aren’t a pilot anymore. They’re a policy choice.

Good news, Thursday! Or at least Interesting News Thursday! As we know, the interconnection queue is killing clean energy projects - but one Illinois solar farm found a way around it, through a gas plant. Having officially achieved commercial operation on June 9, 2026, Earthrise Energy’s Archtop Solar Project, made up of Gibson City Solar 1 and 2 in Ford County, used MISO’s “surplus interconnection service” process rather than applying for a brand-new grid hookup. Under MISO’s surplus interconnection process, a developer can add new generation behind an existing grid connection as long as the total output stays within the original approved limit. Instead of entering the full, backlogged queue, this allows projects to move through a targeted 180-to-270-day review., though it requires a $150,000 deposit and a strict one-year advance application. Earthrise owns both the Archtop solar project and the Gibson City Energy Center gas peaker, and that peaker plant already held interconnection rights for 237 MW of power. Because peaker plants only run during periods of very high demand, that grid connection sits idle most of the time. The solar project uses that idle capacity. On a typical sunny day, the gas plant is off and the solar farm sends power through the shared connection. Because the solar nameplate capacity (270 MWac) is higher than the gas plant’s 237 MW interconnection rights, the project’s control systems can curtail solar output and coordinate with the gas peaker so the combined injection stays within that 237 MW limit. They also work as a team. If clouds suddenly roll in and the solar power drops, the gas plant can instantly turn on to fill the gap and keep power flowing smoothly. By using the surplus interconnection, Earthrise avoided the long studies and network upgrades that often delay new projects for years. Interconnection is now one of the biggest bottlenecks for clean energy in the U.S., with ~8,200 projects waiting years between request and operation and others dropping out entirely. Earthrise is developing approximately 1.5GW comprising 5 solar projects across Illinois using the same surplus interconnection strategy, making Archtop one of the first large utility-scale solar projects to pair directly with an existing gas peaker in this way. With U.S. electricity demand surging, building brand-new transmission lines takes too long to solve our immediate power needs. The Archtop Solar Project proves that the fastest way to build the grid of the future might be to maximize the infrastructure we already have. By treating idle gas plant connections as open real estate, developers can unlock gigawatts of clean energy without waiting a decade for permission to connect to the grid.

I don't think I've fully comprehended that transmission and distribution grids suffer from different types of constraints that can happen at different times of day. For a transmission grid, the issue is that power is needed in a certain area and has to be rerouted to get there (or if you're at the end of the line can't get there at all). For a distribution grid, the issue is that the local power needs cannot be simultaneously served by the equipment deployed to serve it. Both of these issues can be solved by DERs, but sometimes the cure can be worse than the disease. For example, in California the transmission grid underserves the coastal part of the state during the morning and early afternoon, as utility-scale solar needs to get piped in from the east. But the distribution grid starts to suffer in the late afternoon and evening as a/c gets turned on and rooftop solar diminishes. To alleviate transmission congestion, you need to reduce local consumption. The way to do that might seem obvious - rooftop solar - but local substations have limits on how much distributed generation they can send back into the grid. High voltage, fault protection, and thermal limits on equipment mean that after a certain point the substation needs to be upgraded (where things get expensive and rates go up). So the trick is to reduce local consumption as much as possible without going negative. In the evening, there's no longer a transmission constraint, but there is a demand problem. If it's hot and we all want to run our HVAC at the same time, the grid has a hard time handling all the load. But because these two problems happen independently and separately from each other, the DER solution is nuanced. And the situation in California is different than in other places (even in California there are areas where these conditions don't hold). But if you were to solve for the problems of the San Jose area, specifically, where new large loads are going to put stress on the transmission grid, the way that you would mitigate this stress would be to connect storage to existing solar systems (reducing the pressure on local substations during the middle of the day and freeing up power in the evening), or add new combined solar and storage systems where the net export from the house was minimal. We can see this empirically by looking at CAISO LMPs and PG&E GRIP data overlaid on a grid map. Most of the South Bay substations are already at capacity, especially in the northern portion where more affluent communities have invested heavily in residential solar. At the same time there are significant transmission challenges that will only get trickier as more large loads arrive (including EV charging). Siting DERs that are grid-positive is something that utilities are trying to figure out. Once this happens, we can start to move away from standard-offer programs were everyone gets paid the same no matter what, and towards markets that reward strategic investments.

I see solar as a way to solve multiple problems, far beyond energy. Turns out many others think the same way. Here’s the latest example: providing energy, saving water, and keeping farmers on the land. California's Central Valley has a water problem that's reshaping how farmers think about what their land is for. Inadequate and unpredictable water supplies, compounded by the Sustainable Groundwater Management Act's restrictions on groundwater pumping, have forced more than 215,000 acres out of production in the Westlands Water District this year alone. For a growing number of growers there, solar is becoming the answer to a practical question: what do you do with land you can no longer irrigate? In December, the Westlands Water District board approved the Valley Clean Infrastructure Plan, a master-planned project that calls for up to 21 gigawatts of solar and an equivalent amount of battery storage across up to 136,000 acres of fallowed farmland, along with a new high-voltage transmission network to connect the power to California's grid. At full buildout, the project is projected to supply approximately one-sixth of California's electricity needs by 2035. The transmission piece is what makes this unusual. The district will finance and build a 500-kilovolt transmission network, with five new electrical substations and roughly 70 miles of high-voltage lines, designed to speed interconnection to California's congested grid and expand power flows between PG&E and Southern California Edison. One of the project's directors described it plainly: the solar is viable because of the transmission, not the other way around. The plan allows growers to concentrate limited water supplies on their most productive land while generating stable lease revenue from acreage that can no longer support irrigated agriculture. One fifth-generation farmer with 800 acres committed to the plan put it this way: "We're harvesting the sun and producing electricity."  Construction could begin as early as 2028, with initial project energization starting in 2030. The project is expected to generate approximately 10,000 jobs over its life, with roughly 80 percent (around 8,000) filled by local workers. #Agrivoltaics #SolarEnergy #RenewableEnergy

🚨 Faster, Cheaper Grid Connections: Lessons from ERCOT 🚨 In 2023, FERC issued a landmark order to streamline grid interconnection, targeting the massive backlog slowing energy and storage projects. While progress is being made, the ERCOT model—dubbed connect and manage—has sparked attention as a potential game-changer for the rest of the U.S. 🔑 How ERCOT Stands Out: The connect and manage approach focuses on local grid upgrades without requiring expensive network-wide changes. -Uses market redispatch and curtailment to manage grid congestion. -Brings projects online in 3.5 years vs. 6+ years in many regions. For developers, this means less costly interconnection and faster timelines. It’s why ERCOT leads U.S. grid operators, adding 14.2 GW of capacity in 2021-2022, compared to 5.6 GW in PJM, the largest U.S. grid operator. 💡 Why This Matters: As we accelerate the energy transition, ERCOT’s model shows that easing interconnection bottlenecks doesn’t just save time—it also saves money, reduces project risks, and builds resilience into the system. 📚 FERC’s 2023 order laid the groundwork, but adopting ERCOT-inspired innovations like energy-only interconnection options and streamlined study processes could improve grid access nationwide. The path forward isn’t without challenges—operational stability and long-term transmission needs must be addressed. And the connect and manage approach may be less effective in more compressed RTOs/ISOs regions, or smaller non-RTO/ISO regions—but ERCOT’s success proves we can build a faster, more efficient grid⚡ #interconnection #transmission #ERCOT #FERC

The Impact of Large-Scale Solar Power Generation on Network Stability During Fault Conditions The increasing integration of large-scale solar power into electrical networks contributes significantly to reducing carbon emissions. However, it introduces various challenges to grid stability, particularly during fault conditions such as equipment failures or transmission line outages. Key Challenges 1. Intermittency Solar PV systems depend on sunlight, leading to variable power output that complicates grid stability, especially during unexpected faults. 2. Reduced Reactive Power Support Traditional generators provide reactive power, which helps maintain voltage levels. Solar inverters, however, have limited capability to supply reactive power, potentially leading to voltage instability. 3. Transmission Flow Changes Large-scale solar farms are often located far from population centers. This geographical disparity results in new power flow patterns, increased transmission congestion, and reduced efficiency. 4. Lower Inertia Unlike conventional power plants, solar power contributes minimal mechanical inertia to the grid. This makes the system more susceptible to frequency deviations and heightens the risk of widespread blackouts during disturbances. Risks During Fault Conditions • Voltage Instability: Faults may trigger the disconnection of solar inverters, causing abrupt voltage drops. • Frequency Deviations: A lack of inertia means that frequency changes are faster and more severe during faults, increasing the difficulty of maintaining system balance. • Protection System Challenges: The unique behavior of renewable energy systems can disrupt traditional protection mechanisms, leading to delays or errors in fault detection and isolation. Mitigation Strategies 1. Advanced Inverter Technology: Modern inverters equipped with features like synthetic inertia and reactive power support can enhance grid stability during faults. 2. Energy Storage Systems (ESS): Batteries can store excess solar energy and release it during faults, providing the necessary power to maintain frequency and voltage stability. 3. Enhanced Grid Codes: Regulatory measures can mandate fault ride-through capabilities for solar inverters, ensuring their continued operation during disturbances. 4. Dynamic System Planning: Power system models must incorporate the unique characteristics of renewable energy sources to improve fault response and long-term reliability. 5. Distributed Energy Resource Management Systems (DERMS): Real-time control of distributed generation, including solar power, can optimize fault management and system recovery.

New transmission lines to move California’s stranded solar energy could cost more than $1B. Datacenters that productively absorb that energy at the source may be more efficient. In our recent study, we find California curtailed 3.4TWh of renewable energy in 2024, enough to power 500,000 homes for a year. CAISO data shows over 70% of curtailment is caused by local transmission congestion, not system-wide oversupply. The Path 15 corridor through Fresno, which connects Northern and Southern California’s grids, will be congested during 84% of hours by 2039. During the most congested hours, Fresno and Bay Area’s energy prices can differ by as much as $200 per MWh. The conventional fix is up to $1.1B in new high-voltage transmission lines. Our report explores an alternative that moves computation to the energy. A datacenter would be relatively inexpensive to build, productively absorb stranded generation, and ease grid stress. We find that rural datacenters equipped with batteries and sited at congestion points are economically feasible. And such datacenters would reduce pressure on the grid, allowing any new transmission to serve population centers rather than datacenter loads at the destination. Full Report: https://lnkd.in/eW6n3KW5 Thanks to Next 10 for their support and insight into the California context!

Solar electricity every hour of every day sounded impossible five years ago. Today, it's cheaper than coal. Here's what most energy professionals are missing... New data shows we can now achieve 97% constant solar electricity supply throughout the year in sunny regions. Not just during daylight. Every single hour. Including 2am on a cloudy Tuesday in December. The magic number? Just 17 kWh of battery storage paired with 5 kW of solar delivers 1 kW of stable power around the clock. Here's where it gets interesting for different stakeholders: If you're running industrial facilities: Your factories in sunny regions can now operate 24/7 on clean energy at $104/MWh. That's already cheaper than new coal plants at $118/MWh. And costs dropped 22% in just the last year alone. For grid operators wrestling with congestion: This changes your entire playbook. You can now install 5x more solar capacity behind the same grid connection. No expensive infrastructure upgrades needed. Data center developers: Remember those renewable energy commitments? 24/7 clean power PPAs just became real. Not theoretical. Real. Even cloudier regions aren't left behind. Birmingham hits 62% constant supply. Not perfect, but enough to fundamentally shift how we think about baseload power. The game-changer isn't just the technology. It's what happens when solar stops being a "daytime-only" resource. Think about emerging markets. Industrial zones can now pop up in sunny regions far from existing grids. Manufacturing hubs powered entirely by solar. Economic development without waiting decades for transmission lines. Las Vegas gets 97% of the way to true 24/365 solar. Muscat in Oman? 99%. This isn't some distant future scenario. The economics work today. Here's my question for this community: What happens to your business model when solar can deliver the same reliability as traditional baseload power? Because whether you're in traditional energy, manufacturing, or infrastructure development – this shift is coming faster than most boardrooms realize. The companies that see this opportunity first will shape the next decade of energy markets. What's your take? Are we ready for solar that never sleeps? #CleanEnergy #SolarPower #EnergyTransition #Sustainability #RenewableEnergy

Excellent new report from The Brattle Group and Clean Air Task Force, "Optimizing Grid Infrastructure & Proactive Planning to Support Load Growth and Public Policy Goals." The report is a treasure trove of actionable ideas, but two stand out in particular relevant to our research: 𝟭) 𝗠𝗶𝗻𝗶𝗺𝗶𝘇𝗲 𝘁𝗵𝗲 𝗻𝗲𝗲𝗱 𝗳𝗼𝗿 𝘁𝗿𝗮𝗻𝘀𝗺𝗶𝘀𝘀𝗶𝗼𝗻 𝘂𝗽𝗴𝗿𝗮𝗱𝗲𝘀 𝗯𝘆 𝗳𝗮𝗰𝗶𝗹𝗶𝘁𝗮𝘁𝗶𝗻𝗴 𝗰𝗼-𝗹𝗼𝗰𝗮𝘁𝗶𝗼𝗻 𝗼𝗳 𝗻𝗲𝘄 𝗴𝗲𝗻𝗲𝗿𝗮𝘁𝗶𝗼𝗻 𝗮𝗻𝗱 𝗹𝗼𝗮𝗱 𝗶𝗻 “𝗲𝗻𝗲𝗿𝗴𝘆 𝗽𝗮𝗿𝗸𝘀”: Co-locating new load with new on-site generation in controllable “energy parks” (i.e., large microgrids) can minimize or avoid entirely the need for transmission upgrades, increasing speed to market while reducing system and customer costs and potentially providing emissions reduction benefits. 𝟮) 𝗦𝗶𝗺𝗽𝗹𝗶𝗳𝘆 𝗻𝗼𝗻-𝗳𝗶𝗿𝗺, 𝗲𝗻𝗲𝗿𝗴𝘆-𝗼𝗻𝗹𝘆 (𝗘𝗥𝗜𝗦) 𝗶𝗻𝘁𝗲𝗿𝗰𝗼𝗻𝗻𝗲𝗰𝘁𝗶𝗼𝗻𝘀 𝘄𝗶𝘁𝗵 𝘁𝗵𝗲 𝗼𝗽𝘁𝗶𝗼𝗻 𝘁𝗼 𝘂𝗽𝗴𝗿𝗮𝗱𝗲 𝘁𝗼 𝗡𝗲𝘁𝘄𝗼𝗿𝗸 𝗥𝗲𝘀𝗼𝘂𝗿𝗰𝗲 𝗜𝗻𝘁𝗲𝗿𝗰𝗼𝗻𝗻𝗲𝗰𝘁𝗶𝗼𝗻 𝗦𝗲𝗿𝘃𝗶𝗰𝗲 (𝗡𝗥𝗜𝗦, 𝗼𝗿 𝗰𝗮𝗽𝗮𝗰𝗶𝘁𝘆) 𝗹𝗮𝘁𝗲𝗿: Simplifying energy-only interconnection criteria for new POIs to reflect the non-firm (i.e., dispatchable down or curtailable) nature of resources would avoid such time-consuming network upgrades and dramatically speed up interconnection timelines by relying on market-based congestion management to avoid network overloads, as illustrated in a recent Duke University study. Well done Johannes Pfeifenberger Long Lam Kailin Graham Natalie Northrup Ryan Hledik and Nicole Pavia Kasparas Spokas! Summary: https://lnkd.in/eaUmHvgi Full report: https://lnkd.in/eJx-zGzt

𝗔𝗺𝗲𝗿𝗶𝗰𝗮'𝘀 𝗲𝗻𝗲𝗿𝗴𝘆 𝗿𝗲𝘃𝗼𝗹𝘂𝘁𝗶𝗼𝗻 𝗶𝘀 𝗳𝗮𝗰𝗶𝗻𝗴 𝗮 𝗿𝗼𝗮𝗱𝗯𝗹𝗼𝗰𝗸: 𝗮𝗻 𝗼𝘂𝘁𝗱𝗮𝘁𝗲𝗱 𝗽𝗼𝘄𝗲𝗿 𝗴𝗿𝗶𝗱 The US grid is undergoing a significant transformation with the increasing demand for digitalization, renewable energy sources, and sustainability. Solar and battery storage are expected to account for nearly 81% of the new electric-generating capacity in 2024. This hints that our goal of 100% clean energy by 2035 is achievable. However, our energy transmission system needs to be upgraded to make better use of renewable energy. 1200 GW of renewable energy projects are awaiting connection to the grid. The current system is unable to keep pace with the rapid energy transformation. 𝙒𝙚 𝙝𝙖𝙫𝙚 𝙩𝙬𝙤 𝙨𝙤𝙡𝙪𝙩𝙞𝙤𝙣𝙨 𝙤𝙣 𝙩𝙝𝙚 𝙩𝙖𝙗𝙡𝙚 𝙩𝙤 𝙖𝙙𝙙𝙧𝙚𝙨𝙨 𝙩𝙝𝙞𝙨 𝙘𝙝𝙖𝙡𝙡𝙚𝙣𝙜𝙚: "𝗥𝗲𝗰𝗼𝗻𝗱𝘂𝗰𝘁𝗼𝗿𝗶𝗻𝗴 𝗮𝗻𝗱 𝗘𝘅𝗽𝗮𝗻𝗱𝗶𝗻𝗴" Each has its own benefits, but reconductoring is easily achievable and would meet our current needs. 𝗪𝗵𝘆 𝗥𝗲𝗰𝗼𝗻𝗱𝘂𝗰𝘁𝗼𝗿𝗶𝗻𝗴? Replacing existing transmission conductors with advanced core conductors offers; → Higher thermal rates → Reduced sag → Carry more power → Cost saving Besides this, it is a speedy process, unlike new line construction, which can take over a decade due to permitting and land acquisition processes. Reconductoring can meet over 80% of the new interzonal transmission needed to achieve over 90% clean electricity by 2035. Policymakers and grid operators should prioritize reconductoring projects to ensure that the grid can accommodate the rapid expansion of renewable energy and achieve the nation's decarbonization goals efficiently. #innovation #technology #energy #sustainability #electricalengineering ASEC ENGINEERS - Engineering your success, delivering precision and innovation in every project since 1991.