PLUS: Albuquerque's 6 MW municipal solar deal, China's battery manufacturing dominance, and coastal corrosion costs

Subscribe on Substack | Visit solarcurrents.co

Good morning. Ten US states just dismantled one of the biggest barriers to residential solar. Renters can now install plug-in balcony panels without landlord permission, opening clean energy access to 44 million households previously locked out by utility restrictions and building codes.

Utah moved first in May 2025, with nine states following to override the gatekeeping that kept this technology (already standard in Germany) out of US markets for years.

In today's Solarpunk Currents:

• Balcony solar goes legal for renters in ten states
• Albuquerque's 6 MW municipal solar built through private ownership
• China's battery manufacturing dominance reshapes global supply chains
• Coastal corrosion costs hit solar projects built with cheap hardware

Subscribe to Solarpunk Currents on Substack →

Plug-In Solar Breaks Through: Ten States Legalize Balcony Panels for 44 Million Renters

The Bottom Line: Ten US states have legalized plug-in solar panels that renters can install on balconies and patios without landlord permission, opening solar access to 44 million renting households. Utah led in May 2025, followed by Maryland, Maine, Colorado, and six others. State legislatures overrode utility and building code restrictions that kept the technology out of US markets for years, even as it became standard in Germany.

The Story: Renters can now buy a panel, plug it into a standard outlet, and offset grid power immediately. Low-income households and temporary workers under pressure from high electricity bills are adopting the technology as prices approach European cost parity. This is community power vs. utility control: state-level resistance to corporate gatekeeping that locked renters out of rooftop solar.

By the numbers:

• 44 million renting households now have legal access to plug-in solar in ten states
• Utah became the first state to pass legislation in May 2025
• US prices expected to hit European cost parity within months as competition increases
• Technology already standard in Germany's mature plug-in solar market

What remains: Business models are still emerging, and technical and safety standards remain unsettled. Utility opposition continues in states where legislation hasn't passed, and regulatory frameworks for grid integration need standardization.

Albuquerque Builds 6 MW Solar Across City Facilities. Private Company Owns It

The Bottom Line: Albuquerque broke ground on 6 MW of solar across eight municipal facilities through 2027, including animal shelters, pools, a BMX park, and the airport. Sustainability Partners owns and maintains the infrastructure while the city makes monthly usage payments. It's an Infrastructure-as-a-Service model that trades public ownership for faster deployment without upfront capital costs.

The Story: Last week, construction started at the Eastside Animal Shelter and Highland Pool with rooftop and carport installations. The city avoided choosing between climate goals and other capital projects by letting a private company front the money and handle long-term maintenance. Mayor Tim Keller framed it as using "every tool available" to deploy clean energy without putting the full cost on taxpayers.

By the numbers:

• 6 MW of solar deployed across eight city facilities: two animal shelters, three pools, one BMX park, Isotopes Park, the 911 Call Center, Ken Sanchez Transit Facility, and Albuquerque International Sunport
• Airport installation includes 10 EV chargers plus battery storage for critical electrical backup
• Construction phases through 2027 across all eight locations
• City makes monthly usage payments while Sustainability Partners retains ownership and maintenance responsibilities for the system's lifetime

What remains: The 25-year question: Does private ownership with monthly payments serve ratepayers better than municipal bonds or utility ownership? Albuquerque gets solar built now, but we need transparent cost comparisons to know if this model truly serves the public or just privatizes infrastructure that cities could own outright.

The Battery Era Is Here. China Is Building It

The Bottom Line: Global battery deployment hit 1.5 TWh in 2025, up 10x since 2020, with lithium-ion batteries now 93% cheaper than in 2010. China manufactures over 80% of these batteries and dominates every step of the supply chain from mineral processing to cell production. Grid storage grew fastest (19x since 2020), but electric vehicles still account for 70% of battery demand.

The Story: Korean battery giant LG Energy Solution reported it would have lost USD 200 million in 2025 without US manufacturing tax credits. That same year, its Chinese competitor CATL posted 18% operating margins while producing more batteries than LGES, Samsung SDI, SK On, and Panasonic Energy combined. Several Korean producers are now converting US factories planned for EV batteries to serve stationary storage instead, after automakers scaled back electrification plans. The divergence shows how China's manufacturing scale and accumulated expertise create cost advantages that subsidies struggle to match.

By the numbers:

• Battery prices dropped 8% in 2025, with LFP batteries now more than 40% cheaper per kWh than NMC alternatives
• China accounts for over 80% of global battery manufacturing capacity and nearly 75% of batteries deployed in electric cars worldwide
• European Union battery demand will likely exceed 1.0 TWh/year by 2030, but domestic production is projected to cover only 50-60% of demand
• Chinese producers supply over 50% of Europe's EV battery market in 2025, up from 25% in 2023
• US and EU combined account for just 12-14% of global battery manufacturing capacity despite 50% year-on-year capacity growth

What remains: US and European efforts to build domestic battery industries face structural challenges beyond manufacturing capacity. China controls almost the entire supply chain for cathode precursors and LFP materials (the components that determine battery costs). Protectionist policies may strengthen energy security but risk slowing deployment and raising costs when speed and scale matter most for climate goals. The question isn't whether other regions can build batteries, but whether they can do it cost-effectively enough to compete globally while meeting aggressive 2030 targets.

When Salt Air Meets Solar: Coastal Corrosion and the Hidden Costs of Cheap Hardware

The Bottom Line: Solar installations near coastlines face premature equipment failure when builders skip marine-grade corrosion protection to cut costs. A solar park owner in Portugal discovered rusting bolts on a two-year-old installation built by a German EPC company, triggering a warranty claim that exposed how cheap fasteners and inadequate coatings fail in salt air. Asset owners and EPCs are paying for remediation that proper materials would have prevented.

The Story: The owner was walking his dog through the Atlantic coast solar park when he spotted the rust. The project was barely two years old, built with a workmanship guarantee. That warranty claim opened a window into a widespread problem: projects built to lowest bid use standard hardware that corrodes rapidly in marine environments, leaving either the EPC to cover expensive repairs or owners stuck with degrading assets.

By the numbers:

• Solar projects within coastal corrosion zones require stainless steel fasteners and specialized protective coatings that resist salt air exposure
• Standard galvanized steel bolts fail within 2-5 years in marine environments, while marine-grade stainless steel lasts the project lifetime
• EPCs with workmanship guarantees absorb remediation costs; projects without guarantees leave owners facing unplanned maintenance expenses that erode returns
• Proper coastal protection adds 3-5% to balance-of-system costs upfront but eliminates replacement and downtime expenses

What remains: The industry's lowest-bid procurement culture incentivizes EPCs to use inadequate materials on coastal projects, gambling that corrosion won't appear until after warranty periods expire. Projects need site-specific engineering standards that account for salt air exposure, not one-size-fits-all specifications.

The Quick Scribbles

The smarter E Europe trade show demonstrated that 24/7 renewable energy operation is both technically feasible and economically viable, proving the concept works in practice through a live exhibit powered entirely by renewables with battery storage.

GameChange countersued solar tracker rival Nextpower in federal court, escalating a patent war over proprietary hardware and control software that now involves dueling lawsuits between the two companies.

Sungrow raised prices for solar inverters and energy storage products by 5% to 15% starting September 20, citing rising raw material and component costs in its second price increase this year.

NeoVolta secured up to $30 million in growth capital from the RoHo fund to scale domestic battery energy storage system production at its Georgia manufacturing facility.

Solarpunk Currents covers the clean energy transition through a solarpunk lens: community power, climate justice, and imaginative futures. Subscribe on Substack or visit solarcurrents.co.