PLUS: China builds 80% of batteries (is that good?), Albuquerque's solar lease, and when cheap hardware corrodes

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Good morning. Ten US states passed laws allowing renters to install plug-in balcony solar without landlord approval, opening solar access to an estimated 44 million households previously locked out by property ownership requirements and utility gatekeeping.

Utah led in May 2025, with nine states following by this month. It's the German balcony solar model crossing the Atlantic: portable panels that plug into standard outlets, move when tenants move, and let people who'll never own property cut their electricity bills immediately.

In today's Solarpunk Currents:

• Balcony solar laws pass in ten states, reaching 44 million renters
• China builds 80% of batteries while Korean manufacturers scramble for cathode supply
• Albuquerque deploys 6 MW of solar it won't own for 25 years
• When lowest-bid procurement leads to rust at year two

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44 million renters just got access to solar: ten states legalize balcony panels

The Bottom Line: Ten US states overrode utility opposition to legalize plug-in balcony solar for renters. No landlord permission required. Utah passed the first law in May 2025, with Maryland, Maine, Colorado, and six others following. The laws open solar access to an estimated 44 million renter households previously locked out of rooftop solar by landlord gatekeeping and utility interconnection requirements.

The Story: This is the German balcony solar model coming to the US, where low-income households and temporary workers facing high electricity bills can now plug a panel into a standard outlet and immediately cut their power costs. State legislatures chose renters over utilities, ending the homeowner privilege that has defined American residential solar for decades. The laws allow portable panels that move when tenants move, making solar accessible to people who'll never own property.

By the numbers:

• Utah became the first state to pass plug-in solar legislation in May 2025, followed by nine others by September 2026, according to pv magazine
• An estimated 44 million renter households in these ten states can now install balcony solar without landlord approval
• European plug-in solar markets show typical household savings of €100-200 annually per panel, with systems paying back in 3-5 years
• Germany's balcony solar market grew to over 500,000 installations by 2024

What remains: Business models are still forming and prices haven't yet reached European cost parity. Forty states still lack plug-in solar laws, leaving most US renters without access.

The battery question: fast and cheap, or domestic and slow?

The bottom line: Global battery deployment reached 1.5 TWh in 2025, with prices down 93% since 2010. China manufactures over 80% of these batteries and controls 99% of lithium iron phosphate (LFP) cathode production. This creates a climate dilemma: Chinese batteries enable faster, cheaper global decarbonization, but supply chain concentration raises security concerns that push countries toward costlier domestic production with slower deployment timelines.

The story: Korean battery giants Samsung SDI, LG Energy Solution, and SK On are converting EV production lines in their U.S. factories to produce energy storage batteries right now. Samsung is in talks with Tesla for a $2 billion deal to supply 10 GWh annually of LFP batteries for Megapack systems. The problem: they're trying to build a non-Chinese cathode supply chain from scratch while Chinese competitors perfect what took them 15 years to develop. SK On's partnership attempts and LG Chem's Morocco joint venture face the same cathode bottleneck. Most non-Chinese cathode projects won't reach volume production until 2027 or 2028, but their cell plants opening in 2025-2026 need material now.

By the numbers:

• China produced 2.3 million metric tons of LFP cathode material in 2024, up 84% year over year, while non-Chinese capacity barely exists (IEA)
• U.S. grid-scale battery installations hit 5.6 GW in Q2 2025, a quarterly record (Canary Media)
• Korean manufacturers collectively operate over 400 GWh of global battery manufacturing capacity but must compress typical 3-5 year LFP learning curves into 2-3 years (Christopher Chico analysis)
• Sungrow raised inverter and storage system prices 5% to 15% from September 20, citing copper prices up 31.4% and aluminum up 18.8% in H1 2026
• China introduced a 2% consumption tax on lithium-ion batteries September 1, 2026, rising to 4% in 2027 (PV Magazine)

What remains: The 2030 climate window forces a choice that hasn't been resolved: prioritize deployment speed with Chinese batteries that enable faster decarbonization, or accept slower, more expensive buildouts to establish domestic supply chains. Korean manufacturers face a 24-month window to prove they can compete on cost and scale without Chinese cathode materials. If they miss, Chinese manufacturers will find pathways back into restricted markets through partnerships or policy changes. The question isn't technical. It's whether climate targets or supply chain security takes precedence when the two conflict.

Albuquerque deploys 6 MW of solar it won't own

The Bottom Line: Albuquerque broke ground on 6 MW of solar across eight municipal facilities, but Sustainability Partners will own the infrastructure for 25 years while the city makes monthly usage payments. The model eliminates upfront capital costs and includes long-term maintenance, letting Albuquerque deploy clean energy now without competing against other priority projects for limited budget dollars.

The Story: "This is a different approach to how we think about clean energy," said Mayor Tim Keller at the groundbreaking for the city's Eastside Animal Shelter and Highland Pool installations. "We're using every tool available to get more clean energy on the ground without putting the entire cost of building and maintaining these systems on taxpayers." The city is treating solar like a utility bill rather than a capital purchase.

By the numbers:

• 6 MW of solar generation across 8 city facilities, including rooftop and carport installations, with construction phasing through 2027, according to Solar Power World
• Facilities include animal shelter, pools, BMX park, Isotopes Park baseball stadium, transit facility, 911 call center, and Albuquerque International Sunport
• Sunport installation adds 10 EV chargers plus battery storage for critical electrical needs
• City makes monthly payments for 25 years while Sustainability Partners handles installation, ownership, and ongoing maintenance

What remains: The city gets faster deployment and predictable operating costs, but pays monthly for infrastructure it doesn't own. The total cost over 25 years compared to municipal bond financing isn't publicly disclosed. The model answers "how do we deploy now?" but leaves open whether it serves taxpayers better than traditional public ownership.

When cheap bolts cost more: solar hardware fails at two years

The Bottom Line: A two-year-old solar park on Portugal's Atlantic coast started rusting because the construction company installed standard galvanized bolts instead of marine-grade stainless steel fasteners. The German EPC company now faces warranty claims to replace corroding hardware that should have lasted decades. Lowest-bid procurement across the solar industry incentivizes contractors to use inadequate materials that fail within years, gambling that corrosion won't surface until after warranty periods expire.

The Story: The asset owner was walking his dog through the facility when he spotted rust spreading across mounting hardware. The park was barely two years into what should be a 25-year operational life. He called the EPC to invoke the workmanship guarantee. Now the contractor pays to replace components that proper specifications would have protected from day one.

By the numbers:

• Marine-grade stainless steel fasteners add 3-5% to upfront hardware costs but eliminate replacement expenses in coastal and high-humidity environments
• Standard galvanized bolts showed visible corrosion at 2 years in Atlantic coastal conditions
• EPCs face full replacement costs when corrosion appears during warranty periods, erasing any savings from cheaper materials
• Premature hardware failure reduces energy output and requires costly maintenance visits throughout project life

What remains: Procurement culture prioritizes initial bid price over lifecycle costs, pushing EPCs to cut corners on components that asset owners and ratepayers ultimately pay to replace. Until contracts reward total cost of ownership rather than lowest upfront bids, builders face pressure to install infrastructure designed to corrode.

The Quick Scribbles

Lineage sued solar installers and maintenance contractors over a $1 billion fire at its California cold-storage facility, claiming the blaze started in an improperly maintained rooftop solar array after the company issued multiple ignored safety warnings.

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.