Solar Panels Are Three Times More Carbon-Intensive Than IPCC Claims

Ecoinvent, the world’s largest database on the environmental impact of renewables, has no data from China, even though it makes most of the world’s solar panels.

This investigation was done in collaboration with Environmental Progressand The Blind Spot

Last August, in an amalgamation of “The Green New Deal” meets “Build Back Better,” President Joe Biden’s Inflation Reduction Act gifted the renewables industry with billions of dollars worth of taxpayer-funded subsidies. 

What few backing the bill realized was that the largest beneficiary would likely be China due to its expansive grip on the global solar photovoltaic (PV) industry. Worse than that, it might end up misdirecting the world’s clean energy efforts into dirtier than appreciated energy technologies because of the country’s ongoing dependence on coal-fired energy.

Information unearthed by Environmental Progress, a nonprofit research organization, points to a gaping oversight in how the figures influencing government net zero policy and investments in solar worldwide are compiled and collated due to the difficulty of collecting accurate information out of China, especially for the purification processes used to create silicon wafers.

The key to this blind spot is that a small number of data compilers provides the source material for most of the assessments. And many, if not all, of them work in collaboration with the International Energy Agency (IEA). The industry voluntarily submits the data in response to academic surveys. The nature and profile of the respondents are never publicly revealed, so there is the potential for conflicts of interest to develop.

A further puzzle is how that data feeds into an organization called Ecoinvent, a Swiss-based non-profit founded in 1998 that dubs itself “the world’s most consistent and transparent life cycle inventory database.” This data is relied on by institutions worldwide, including the IPCC and IEA itself, to calculate their carbon footprint projections, including the sixth assessment report published as recently as March 2023.

Based on such data, the IPCC claims solar PV is 48 gCO2/kWh. But, as we’ll see below, a new investigation started by Italian researcher Enrico Mariutti suggests that the number is closer to between 170 and 250 gCO2/kWh, depending on the energy mix used to power PV production. If this estimate is accurate, solar would not compare favorably with natural gas, which is around 50 gCO2/kWh with carbon capture and 400 to 500 without.

Over the course of a four-month investigation, Environmental Progress has confirmed that Ecoinvent — perhaps the world’s largest database on the environmental impact of renewables — has no data from China about its photovoltaic industry. Meanwhile, the ultimate source of the IEA’s supposedly public data on PV carbon intensity is confidential, and the data, therefore, is unverifiable.

Much of the cradle-to-grave carbon intensity data that governments depend on to guide photovoltaic arrays are instead based on modeling assumptions that are likely to have grossly under-estimated — if not made up — solar’s carbon emissions because they cannot get insights from Chinese manufacturers.

In its most recent report, the IEA predicts that China will continue to dominate solar energy production, delivering over 50 percent of solar PV projects globally by 2024. This trajectory is especially concerning given that China already commands most solar panel production.

The IEA noted that in 2022 China’s manufacturing capacity for wafers, cells, and modules rose 40-50 percent and almost doubled for silicon. In fact, according to market intelligence firm Bernreuter Research, in 2021, China produced more than 80 percent of global solar-grade polysilicon, a critical input into solar arrays. It doesn’t stop there; China manufactures 97 percent of the global supply of solar wafers, another essential component.

How China amassed that market concentration remains an inconvenient truth, all too readily swept under the rug by those pushing for net zero policies.

What we know for sure is that up until the mid-2000s, the market was dominated by Japanese, US, and German manufacturers, many of whom were in the midst of automating their production lines, when Chinese manufacturers swooped in to take their market share. The disruption happened in under a decade, with China’s global share of PV production surging from 14 percent in 2006 to 60 percent by 2013.

But the majority of experts consulted by Environmental Progress agree that China’s competitive advantage did not lie in an innovative new technological process but rather in the very same factors the country has always used to outcompete the West: cheap coal-fired energy, mass government subsidies for strategic industries, and human labor operating in poor working conditions.

Basic reasoning suggests the manufacturing shift must have added to solar’s carbon intensity. But as Environmental Progress has learned, nobody in the carbon counting world has seen fit to research by how much. The modelers are estimating the carbon emissions of solar production as if the panels are still made mostly in the West, grossly underestimating their carbon intensity, even as governments rush to draft and implement net zero policy based on the very same flawed data.