Solar Panel Waste is Tiny—Coal & Gas Emit Hundreds Of Times Mass Per MWh

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Every few months, another wave of media reports predictably warns about the supposed “looming crisis” of solar panel waste. Given the urgency of climate action, it’s frustrating to see the conversation repeatedly derailed by these exaggerated concerns. I’ve previously examined this narrative around wind energy, demonstrating clearly in my CleanTechnica analysis that wind turbine waste per megawatt-hour generated is tiny compared to the truly monumental environmental impact of coal and gas. It’s past time I applied a similar perspective to solar photovoltaics.

Solar panel waste does exist, to be sure, and it has grown alongside the rapid global deployment of solar energy. Between 2020 and 2024, the global mass of discarded solar panels roughly quadrupled, rising from about 220,000 tonnes annually in 2020 to approaching 900,000 tonnes by 2024. These numbers sound significant on their own until we put them in proper context. The vast majority of this waste comes not from natural end-of-life retirement after 25–30 years, but from early replacements due to storm damage, economic upgrades, or manufacturing defects in early panel generations. According to the International Renewable Energy Agency (IRENA), over 90% of panels scrapped before 2030 represent premature retirements rather than panels reaching their natural end-of-life. This pattern is common for many emerging technologies, where initial product iterations may see higher early failures, leading to accelerated replacement rates.

Yet even considering early panel retirements, the actual waste per megawatt-hour of electricity generated by solar panels remains remarkably small. A typical solar panel today weighs about 20 kilograms and, over a realistic 25-year lifespan under moderate sunlight conditions, generates approximately 10 megawatt-hours of electricity. Doing simple math, that works out to roughly 2 kilograms of solid waste per megawatt-hour produced. Independent studies support this estimate; for example, recent research published in Nature Physics estimated solar panel waste at approximately 1.7 kilograms per megawatt-hour.

Now let’s place solar waste firmly in perspective against coal and gas, two widely used fossil fuels still dominating electricity generation globally. Coal plants generate huge amounts of solid waste as fly ash and bottom ash, averaging around 80 to 100 kilograms per megawatt-hour—forty to fifty times more waste per unit energy than solar panels produce. Moreover, coal combustion also emits enormous amounts of carbon dioxide, roughly 950 kilograms per megawatt-hour according to the U.S. Energy Information Administration (EIA), about 500 times more. Natural gas, cleaner burning than coal, nonetheless emits about 450 kilograms of CO₂ per megawatt-hour generated, over 200 times more. Though gas plants produce no ash waste, their continuous carbon emissions still place them far above solar in environmental impact per unit of energy.

Comparison of waste and CO2 emissions per megawatt-hour for solar PV vs. coal and natural gas power

Let’s pause and clearly visualize this difference. Here’s how these waste streams compare side-by-side, measured per megawatt-hour of electricity generated: Solar PV produces about 2 kilograms of solid waste, coal plants produce around 90 kilograms of toxic ash along with 950 kilograms of CO₂ emissions, and gas plants produce nearly 450 kilograms of CO₂ without any significant solid waste. The disparity is staggering. Fossil fuel plants not only produce ongoing, massive atmospheric pollution, but coal combustion also creates substantial, toxic solid waste that dwarfs solar waste many times over.

Beyond sheer quantities, there’s the matter of toxicity and environmental consequences. Solar panel waste primarily comprises glass, aluminum frames, silicon, and minimal plastics, over 80% of which are highly recyclable and inert. Even panels containing trace amounts of heavy metals, such as cadmium or lead, pose minimal environmental risk due to their encapsulation and recyclability. In contrast, coal ash is laden with hazardous substances, including arsenic, mercury, lead, selenium, and uranium. This toxic cocktail presents serious, proven health risks if it contaminates groundwater, soil, or becomes airborne through improper disposal or spills. Environmental disasters like the infamous coal ash spill in Kingston, Tennessee, which released millions of tonnes of toxic sludge into surrounding communities and waterways, underscore this point vividly.

Moreover, coal and gas combustion emissions are the primary contributors to global warming, driving catastrophic climate change effects that dwarf any hypothetical risks from inert solar waste. According to recent analysis by the Global Carbon Project, coal combustion alone produced around 15 gigatonnes of carbon dioxide annually during the 2020–2024 period, with gas adding another 7 to 8 gigatonnes each year. Combined, this totals well over 100 billion tonnes of carbon dioxide emitted into our atmosphere in just five years—emissions that will persist for centuries, driving climate instability and severe impacts on ecosystems, economies, and human lives worldwide. A study published by the British Medical Journal links fossil fuel air pollution to roughly 5 million premature deaths annually worldwide, primarily due to respiratory illnesses, cardiovascular diseases, and strokes. Solar panels, meanwhile, release no pollutants during their decades of clean operation and negligible environmental harm after retirement.

So why the continual, exaggerated drumbeat of concern over solar panel waste? Part of the reason, frustratingly, lies in misplaced priorities by advocates for decarbonization, and then there’s the deliberate narrative-setting by fossil fuel interests seeking to slow the inevitable energy transition. A substantial and growing solar recycling infrastructure already exists, particularly in regions like the EU, which mandates 85% recycling of photovoltaic modules under its WEEE Directive. Recycling methods are proven, scalable, and environmentally sound. Solar waste represents a small, manageable, and largely benign material stream.

Instead of magnifying modest challenges associated with clean technologies, our attention would be far better focused on confronting the genuinely catastrophic environmental impacts of fossil fuel generation. It’s vital to maintain clear-headed, data-driven perspectives. The reality is straightforward: every megawatt-hour produced by solar panels means significantly less waste and dramatically fewer emissions compared to coal or gas.

Here is the direct comparison, clearly stated once more for emphasis: Solar generates approximately 2 kilograms of inert, recyclable waste per megawatt-hour. Coal generates around 90 kilograms of highly toxic ash per megawatt-hour along with nearly a tonne of CO₂. Gas generates roughly half a tonne of CO₂ per megawatt-hour, along with the attendant methane leakage upstream. By any sensible measure, solar panel waste is trivial by comparison. The ongoing attempt to frame solar waste as a crisis or even an issue is not only misplaced but actively counterproductive, distracting us from the far more urgent issues of climate change and fossil fuel pollution.

The pathway forward is clear. Solar panel recycling infrastructure can and will scale to handle future volumes. We know how to do this; technologies and systems already exist and are rapidly expanding. Coal and gas emissions, on the other hand, cause irreversible and compounding harm. Every megawatt-hour of clean electricity we generate from solar power today means drastically reduced long-term environmental harm compared to fossil fuels.

Let’s end the misleading narratives around solar waste and instead focus our efforts and policies squarely on phasing out the genuinely catastrophic environmental impacts of coal and gas generation. The data are clear, the science is unambiguous, and the stakes could hardly be higher. Solar waste isn’t the crisis—fossil fuels are.