John Weaver
- Project Developer, Commercial Solar Guy
- Contributing Editor, PV Magazine
Boston, Massachusetts, United States
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Articles by John Weaver
“Moving into a positive political environment for solar” – is the ITC coming back?
Even before the midterm election results, Roth Capital’s Philip Shen, managing director and senior research analyst, had been hearing that the solar tax credit was still on the minds of many in Washington D.C. “Our checks suggest that Republicans are open to extending the ITC and 45X.
White House promotes T1 Energy’s Texas solar manufacturing push ahead of supply chain ruling
The White House X account (formerly known as Twitter) reposted a message from T1 Energy on October 28. The post from T1 Energy talked up the administration’s visit to Texas, their continued support, and pointed out the company’s two Texas facilities: “T1 is building G2_Austin, an advanced photovoltaic manufacturing facility in Texas, with an estimated 2.1 GW Phase 1 capital expenditure in excess of $500 million.
Batteries delivering Americans hundreds of millions in benefits annually
A report from the Rocky Mountain Institute (RMI), Stored Potential: The impacts of utility-scale battery energy storage systems on communities and the grid, attempts to highlight and quantify reliability contributions, economic and fiscal impacts, health and environmental benefits, and the evolving safety landscape of utility scale batteries.
BloombergNEF forecasts 584 GW of solar installations in 2026
In December 2025, BloombergNEF projected a pullback in global solar installations, with China slowing and the rest of the world growing. Ten months later, China has slowed more than expected. The rest of the world has grown slightly faster. BloombergNEF now projects 584 GW of solar installations in 2026. That is a 10.8% decline from 655 GW in 2025. In December, it forecast 649 GW. In the first quarter of 2025, it expected 753 GW. That earlier 2026 figure is 29% higher than today’s forecast.
Rooftop solar growth makes giant New England gas plant obsolete as region hits 500th Duck Curve day
The group tasked with managing the power grid, Independent System Operator New England (ISO-NE), noted New England’s 500th solar duck curve day on September 21, 2026:. The ISO noted the first duck curve in the region on April 21, 2018. Mike Knowland, ISO-NE’s manager of Forecast & Scheduling noted, “The 500th duck curve could have come earlier, but there were a lot of cloudy days this year.” ISONE wrote, “It took nearly five years for the region to accumulate its first 100 duck curve days.
Rooftop solar growth makes giant New England gas plant obsolete as region hits 500th Duck Curve day
The group tasked with managing the power grid, Independent System Operator New England (ISO-NE), noted New England’s 500th solar duck curve day on September 21, 2026:. The ISO noted the first duck curve in the region on April 21, 2018. Mike Knowland, ISO-NE’s manager of Forecast & Scheduling noted, “The 500th duck curve could have come earlier, but there were a lot of cloudy days this year.” ISONE wrote, “It took nearly five years for the region to accumulate its first 100 duck curve days.
California home batteries set VPP dispatch record during heat wave
Some batteries across California discharged at a peak of more than 580 MW on the evening of Sept. 9, which Tesla and Sunrun said it was the largest residential VPP dispatch on record. The California Energy Commission (CEC) called on the batteries as a heat wave pushed up demand and wholesale prices. Tesla Powerwalls accounted for 517 MW, while batteries from other manufacturers added 63 MW. About 110,000 Powerwalls took part, 55% of them owned and operated by Sunrun.
California VPPs hit record during heatwave as bill sits on Governor’s desk
Home batteries across California discharged at a peak of more than 580 MW on the evening of Sept. 9, which Tesla and Sunrun said it was the largest residential virtual power plant (VPP) dispatch on record. The California Energy Commission (CEC) called on the batteries as a heat wave pushed up demand and wholesale prices. Tesla Powerwalls accounted for 517 MW, while batteries from other manufacturers added 63 MW. About 110,000 Powerwalls took part, 55% of them owned and operated by Sunrun.
Responsible solar siting in the time it takes to make coffee
We already have the ability to move through whole countries via Google Street View. Video games like Grand Theft Auto let you walk the streets of complex cities and their surroundings. Maybe a solar land analysis tool will do the same one day? While you can’t do it on a PlayStation, Glint Solar does have a goal of giving you the ability to explore whole states at once, but in a locally precise, and responsible solar manner.
U.S. DOE seeks ‘mass, radiation tolerance, and durability’ in space solar cell manufacturing
The U.S. Department of Energy (DOE) Integrated Energy Systems Office (IESO) and Office of Critical Minerals and Energy Innovation are seeking innovative techniques to move space based solar power forward. The groups are launching a $12 million funding opportunity open to research laboratories and companies around the country. Space based solar has gotten a lot of attention lately. Some propose to power data centers in space, while others seek to beam the energy to Earth.
DOE seeks “mass, radiation tolerance, and durability” in space solar cell manufacturing
The U.S. Department of Energy (DOE) Integrated Energy Systems Office (IESO) and Office of Critical Minerals and Energy Innovation are seeking innovative techniques to move space based solar power forward. The groups are launching a $12 million funding opportunity open to research laboratories and companies around the country. Space based solar has gotten a lot of attention lately. Some propose to power data centers in space, while others seek to beam the energy to Earth.
LONGi energy strategy is not just “one plus one”
LONGi is one of the largest energy companies on Earth, operating at the center of the fastest-expanding source of energy generation: solar power. The manufacturer continues to deliver among the market’s most efficient solar modules, including a back-contact unit exceeding 25% efficiency. Now, the company is expanding heavily into energy storage through its LONGi ONE strategy.
The world’s most efficient solar panel goes on sale later this year
Tandem PV shipped its “first production-quality panel” two weeks ago and expects revenue-generating sales later this year, according to CEO Scott Wharton. To achieve bankability, Tandem will begin running paid pilot deployments with independent power producers (IPPs) later this year. Those paid deployments will begin the outdoor testing required for bankability, which Wharton said could be achieved after roughly 6 to 12 months of field data.
The world’s most efficient solar panel goes on sale later this year
Tandem PV shipped its “first production-quality panel” two weeks ago and expects revenue-generating sales later this year, according to CEO Scott Wharton. To achieve bankability, Tandem will begin running paid pilot deployments with independent power producers (IPPs) later this year. Those paid deployments will begin the outdoor testing required for bankability, which Wharton said could be achieved after roughly 6 to 12 months of field data.
Who controls solar operations? Connecticut fire highlights state oversight loophole
A fire started by utility equipment connected to a solar power plant in Connecticut was put out quickly. However, the plant has had continued issues, causing much local consternation, to the point where the facility is currently shut down. These issues, coupled with the facility owner’s defense stating neither the state or the utility can tell it how to run said power plant, is now raising rankles further.
To sell solar, sell the family, support the champion, and mind the timing
Researchers from Ohio State University and Southern Illinois University have found that households, versus individuals, make solar purchasing decisions happen. Because buying solar is so confusing, the family member driving the project, or the solar “champion” often gets exhausted. Solar companies need to support this person to keep the sale from falling apart, said the report.
A rebuildable solar array to train students and access ‘beginner’s mind’
Derek Mast, a Pennsylvania master electrician, has assembled – and is ready to disassemble – a training solar system at the Lancaster County Career and Technology Center. The purpose of the 6.4 kW solar-plus-storage system, said the installer and father, is to train the future. Grants for workforce training from a local power company and the Lancaster County Career and Technology Foundation made the project possible.
A rebuildable solar array to train students and access “beginner’s mind”
Derek Mast, a Pennsylvania master electrician, has assembled – and is ready to disassemble – a training solar system at the Lancaster County Career and Technology Center. The purpose of the 6.4 kW solar-plus-storage system, said the installer and father, is to train the future. Grants for workforce training from a local power company and the Lancaster County Career and Technology Foundation made the project possible.
Arizona appeals court vacates APS solar-specific charge over due process violations
In a unanimous ruling, the Arizona Court of Appeals has officially vacated the discriminatory solar-specific grid charge levied against Arizona Public Service (APS) rooftop solar customers. The court threw out the fee after determining that the Arizona Corporation Commission (ACC) violated procedural due process by adopting the mechanism without proper public notice or a fair hearing.
How massive subsidies helped drive a 90% collapse in solar costs
According to data collected by the Organisation for Economic Co-operation and Development (OECD), in its OECD MAGIC Database of Industrial Subsidies, China has subsidized its solar power-related manufacturing industries by $17.4 billion from 2010 through 2024. In contrast to China’s huge investment, OECD countries — 38 member states primarily located in Europe and the Americas, including the U.S. — have subsidized their manufacturers by just $3.9 billion over the same period.
The world’s magical $21 billion investment
According to data collected by the Organisation for Economic Co-operation and Development (OECD), in its OECD MAGIC Database of Industrial Subsidies, China has subsidized its solar power-related manufacturing industries by $17.4 billion from 2010 through 2024. In contrast to China’s huge investment, OECD countries — 38 member states primarily located in Europe and the Americas, including the U.S. — have subsidized their manufacturers by just $3.9 billion over the same period.
Global solar demand on track for first annual decline in two decades
In late 2025, BloombergNEF (BNEF) projected that 2026 would be the first down year for solar panel installations in two decades. As of its presentation at SNEC 2026 in Shanghai, with Chinese capacity installations slowing significantly versus the prior year at this point, it looks like this projection may come true. BNEF solar analyst Jenny Chase examined why the ongoing wars have a limited effect on solar, and what might pull the solar module industry from its doldrums.
U.S. court restores 5% safe harbor for wind and large solar
In a ruling with national implications, the US District Court for the District of Columbia found that the Internal Revenue Service (IRS) acted in an “arbitrary and capricious” manner when it dictated that wind and solar power facilities were no longer eligible to use the 5% safe harbor method to lock in the tax credit in Notice 2025-42 (the Notice). The court vacated the Notice nationwide and sent it back to the IRS.
Court restores 5% Safe Harbor for wind and large solar
In a ruling with national implications, the US District Court for the District of Columbia found that the Internal Revenue Service (IRS) acted in an “arbitrary and capricious” manner when it dictated that wind and solar power facilities were no longer eligible to use the 5% Safe Harbor method to lock in the tax credit in Notice 2025-42 (the Notice). The court vacated the Notice nationwide and sent it back to the IRS.
25% is the new 23%
On the floor at SNEC 2026 in Shanghai, the world’s largest solar and energy storage trade show, one trend is clear: standard silicon module efficiencies continue to rise. Modules with 25% efficiency are now commonplace, while 23% has effectively become the floor and 24% the mainstream product level. Two years ago, at Intersolar Munich, Aiko Solar introduced what was then the market’s first 25% solar module.
25% is the new 23%
On the floor at SNEC 2026 in Shanghai, the world’s largest solar and energy storage trade show, one trend is clear: standard silicon module efficiencies continue to rise. Modules with 25% efficiency are now commonplace, while 23% has effectively become the floor and 24% the mainstream product level. Two years ago, at Intersolar Munich, Aiko Solar introduced what was then the market’s first 25% solar module.
‘Buy the dip’ on T1 Energy’s Fuzzy Panda domestic doubt, Roth says
A report by Fuzzy Panda Research questioning T1 Energy’s ability to deliver solar modules that qualify for the 45X advanced manufacturing tax credit or the 10% domestic content Inflation Reduction Act adder triggered a sell-off of as much as 13% on Tuesday, May 19. That same day, Roth Capital Partners analyst Philip Shen published a note titled “Another Misleading Short Report; Buy the Dip,” pushing back on the thesis.
U.S. House wants to tax EV $130/year – equal to an 18.3 MPG car
The U.S. House of Representatives is considering a $130 annual fee on electric vehicles (EVs), $35 on plug-in hybrids, and nothing on internal combustion (ICE) vehicles. Starting in 2029, the fee would rise $5 every two years, capping at $150 for EVs and $50 for hybrids. The fee would take effect Oct. 1, 2026, and expire in 2036. The language sits in Sec.
U.S. Solar developer seeks connection to wrong powerline, delays project five years
From pv magazine USA A solar power project based in Mount Jackson, Virginia submitted interconnection documentation with the wrong electric pole specified. They estimate that the project will be delayed by five years. Based on the Mount Jackson Town Council Agenda Report on the session from April 21st, 2026, “OFW Solar Project LLC” could potentially be delayed from starting construction until 2032.
Solar developer seeks connection to wrong powerline, delays project five years
A solar power project based in Mount Jackson, Virginia submitted interconnection documentation with the wrong electric pole specified. They estimate that the project will be delayed by five years. Based on the Mount Jackson Town Council Agenda Report on the session from April 21st, 2026, “OFW Solar Project LLC” could potentially be delayed from starting construction until 2032.
U.S. solar panel manufacturers need to learn to solder
From pv magazine USA Intertek CEA’s Global PV Manufacturing Quality Report 2026 suggests there is much work to be done to improve the quality of solar module manufacturing. The report states that more than 70% of factories were rated in the lowest two tiers — C or D — in 2025 factory audits, and none achieved an A+. Source – Intertek CEA One of the report’s central points is that most issues arise during factory ramp-up after construction, and again during capacity expansions.
U.S. solar panel manufacturers need to learn to solder
Intertek CEA’s Global PV Manufacturing Quality Report 2026 suggests there is much work to be done to improve the quality of solar module manufacturing. The report states that more than 70% of factories were rated in the lowest two tiers — C or D — in 2025 factory audits, and none achieved an A+. Source – Intertek CEA One of the report’s central points is that most issues arise during factory ramp-up after construction, and again during capacity expansions.
Medium duration storage endures woes, while Form’s long duration grows, and lithium overflows
Form Energy launched what may be the world’s largest battery, ESS is functionally out of cash, and EOS is missing revenue. In short, the medium and long duration energy storage market is in flux, and it’s being casually hunted by competitive innovation and lithium ion. As far as medium duration is concerned, EOS and ESS are attempting to shift the market.
Tesla energy storage deployments down 15% on ‘clumpy’ first quarter
Tesla’s energy division continues to grow in importance at the company, though deployments fell 35% at the start of the year amid “clumpy” first quarter numbers. The division deployed 8.8 GWh of storage and earned $2.4 billion in revenue. Gross profit for the division touched nearly 40%.
Batteries reshape solar pricing in California market
From pv magazine USA According to a new report by Aurora Energy Research, “increasing battery charging demand is raising mid-day prices” in the CAISO electricity market. The chart below shows CAISO wholesale electricity rates during a March 20 five-minute bidding window. The gold line shows the actual pricing that was cleared for the electricity at negative $8.34/MWh. The red line shows a hypothetical clearing rate of -$50/MWh, if there were no batteries bidding.
Batteries buying “free” California solar, driving up price
According to a report by Aurora Energy Research, “increasing battery charging demand is raising mid-day prices” in the California Independent System Operator (CAISO) electricity market region. The chart below shows CAISO wholesale electricity rates during a March 20th five-minute bidding window.
Energy tax credit restoration bill submitted to Congress
A bill, the Energy Bills Relief Act, was introduced to the U.S. Congress on March 18, 2026. The 419-page bill explicitly rolls back any changes made by last year’s One Big Beautiful Bill to clean energy tax credits.
Seeing shortage, California seeks 6 GW clean power capacity
In 2019, California predicted a coming energy shortfall during the first half of the 2020s. Turns out, there were multiple outages during record-high demand events. The state also showed that it could deploy energy storage in enough capacity to protect its power grid. On February 26, 2026, the state voted to address the next perceived energy shortfall, projected to happen sometime in the early 2030’s.
Alabama senator seeks statewide ban on solar installations
Alabama Senator Greg Albritton (R) has introduced AL SB354, which seeks to pause all solar power construction statewide. The bill made it out of its initial committee on March 11, and was introduced to the broader legislative body on March 26. As the bill is currently written, it would be implemented immediately upon appropriate signatures being collected.
US solar generation reaches 385 TWh in 2025 as power demand rises
From pv magazine USA In 2025, solar accounted for just over 8.5% of all US electricity generated. In absolute terms, solar generated 385 TWh of electricity. These values represent increases of nearly 25% last year, and just over 28% in 2024. If solar growth had continued at the 2024 record rate of 50 GW, solar may have constituted 10% of US electric generation in 2026.
Solar’s fastest growth in a decade, fossils fall again, but emissions rise
In 2025, solar accounted for just over 8.5% of all U.S. electricity generated. In absolute terms, solar generated 385 TWh of electricity. These values represent increases of nearly 25% last year, and just over 28% in 2024. If solar growth had continued at the 2024 record rate of 50 GW, solar may have constituted 10% of U.S. electric generation in 2026.
Batteries replace diesel backup at wastewater plant in New York
From pv magazine USA Viridi has replaced a diesel backup generator with a battery system at a municipal wastewater pumping station in Erie County, New York. Depending on pump demand, the 150 kWh RPSLink system can provide power for 32 to 90 hours. The $130,000 lithium-ion Nickel Manganese Cobalt battery system was custom designed to align with the energy demands of the onsite pumps.
Batteries backing up wastewater plant and replacing generators
Viridi announced a successful replacement of a diesel backup generator by its battery system at a municipal wastewater pumping station in Erie County, New York. Depending on pump demand, the 150 kWh RPSLink system can deliver energy for 32 to 90 hours. The $130,000 lithium-ion Nickel Manganese Cobalt battery system was custom designed to align with the energy demands of the onsite pumps.
Republicans pushing for clean energy tax credit: “We think [Trump] is getting bad advice
According to an interview with Politico, U.S. Representative Brian Fitzpatrick (R-PA.) has begun a push to reinstate the wind and solar tax credits that were cut when the One Big Beautiful Bill (OBBB) was signed. Regarding Trump’s disdain for renewables, Fitzpatrick commented: “We need to change that position. Because I think he’s getting bad advice on this.” Fitzpatrick is a member of the influential Ways and Means Committee, which is responsible for writing tax laws. Politico also noted that Rep.
California batteries sustain near 24-hour solar run
From pv magazine USA Technically, all batteries can be run as ‘long duration’ batteries, and they can run for twenty four hours so long as the power output is limited relative to the stored energy. However, when some batteries run overnight it means a little more. On Feb. 1, batteries gave just a little more in the California Independent System Operator (CAISO) power grid region.
When the sun sets, batteries rise: 24/7 solar in California
Technically, all batteries can be run as ‘long duration’ batteries, and they can run for twenty four hours so long as the power output is limited relative to the stored energy. However, when some batteries run overnight it means a little more. On Sunday, Sunday February 1, 2026 in the California Independent System Operator (CAISO) power grid region, batteries gave just a little more.
Missouri declares war on solar
From pv magazine USA Missouri State Senator Cindy O’Laughlin (R-18) introduced Senate Bill 849 (SB 849), which would halt all ongoing and new utility-scale solar construction in the state until environmental rules governing construction, placement, and operation are established. The bill imposes an immediate moratorium on “new and current” solar projects statewide.
How to design a UL-certified balcony solar kit in the United States
From pv magazine USA UL Solutions has released new design guidance and a proposed certification framework for balcony solar, also known as plug-in PV (PIPV), as US policymakers and manufacturers begin to explore consumer-installed solar systems that connect directly to wall outlets.
How to build a balcony solar kit to UL standards
UL has released a white paper, “Interactions of Plug-In PV (PIPV) with Protection of Existing Power Systems”, which outlines the safety implications of consumers plugging solar panels directly into wall outlets, and guides for companies designing new products in this space. Vice President of Principal Engineering, Ken Boyce, of UL spoke with pv magazine USA about some of these challenges, and their perspective on new technology.
New Jersey governor orders major solar, storage expansion on first day
From pv magazine USA On her first day in office, New Jersey Governor Mikie Sherrill signed Executive Order No. 1 and No. 2, which focus on maintaining electricity prices and providing solar and energy storage, respectively. Governor Sherrill enacted Executive Order No. 1 to address the rising prices of electricity, and then guided her Board of Public Utilities(BPU) to freeze or limit electricity supply rate increases.
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