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Jessica, you write: "It is unclear whether solar panels over their lifetime can even offset the carbon generated during their manufacturing." What is you source for this?

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Hi Tim, The carbon footprint break-even point depends on many factors, primarily how much carbon was generated during the manufacturing process, including extraction and processing of the raw materials, vs how much solar energy is being put to use. This depends heavily on the individual installation. Is the excess energy produced being stored, sent back to the grid, or is it being lost? Are the panels stationary or tracking? Are the panels installed at the optimal angle? There are also regional factors such as cloud cover and latitude. Due to these factors, each installation will have its own break-even point. This is why I said that it was unclear whether solar cells will completely offset the carbon generated through manufacturing. For example, a coal fired power plant like you would find in China where these panels are made produces 2.5 times the amount of CO2 per KWH than a natural gas fired plant. If you are installing your panels in a region that already has clean municipal power, then your CO2 break-even will take much longer or never be realized. Incentives and rebates for Oregon homeowners to install solar panels will have no measurable impact on climate change. I believe the most effective clean energy decisions must be made at the grid level.

https://www.onlynaturalenergy.com/the-true-carbon-footprint-of-photovoltaic-energy/

https://www.altenergymag.com/article/2005/08/solar-energy-potential-at-different-latitudes/120/

https://www.eia.gov/todayinenergy/detail.php?id=18871

https://www.semprius.com/solar-panel-angle-calculator/

https://www.eia.gov/tools/faqs/faq.php?id=74&t=11

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Thanks, Jennifer. I appreciate the complexity of all that goes into the manufacture and deployment of solar arrays. It seems daunting, but doable, to get more detailed assessments of these projects before they are undertaken. We have a sizable ground-mounted solar array (17 kWh) at our homesite, supporting our home, adjacent cabin and garage/shop. We're generating more power than we use now, with the excess going to the grid. But our next vehicles will be EVs, so we expect to use all of the power we're generating in the future. How we use this power seems to me to be another factor to consider in these calculations, including, specifically, what we're replacing with the solar power. Substituting soalr-gernerated electricity for gasoline should be among the best-case uses. Also, having a battery backup system is a big convenience for us and was a selling point as well. Resilience in the face of extreme weather events is also a need that can be addressed by these systems.

My last point is more of an intuition about the positive spill-over effects of small-scale projects like mine. The more people who turn to solar, the more they are likely to purchase EVs, use battery-powered tools, share home-based chargers for their visitors' EVs and have their neighbors get interested in following their lead. This can create a culture of "cool new things" that can "scale" in a different, more cultural, way. Small projects may not, at first glance, appear to "get to scale," but they can change minds, lead to more uses than first envisioned and reveal new potentials. On that last point, I see considerable unused areas of land for solar arrays on rural properties that represent more potential than can be matched by panels on urban rooftops.

Based on the number of start-ups focused on large-scale industrial batteries and electric buses and trucks and the research into the development and deployment of green hydrogen, I think the big, scalable projects are getting their due. But I also think that the deployment of small-scale systems, widely distributed, especially in rural areas, can play an important role in the electrification of homes and autos, generating popular interest and accelerating the shift to a green energy economy.

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From a quick check, even if fossil fuels are used to generate the energy needed for the manufacture of solar panels (not necessarily the case if we change our manufacturing processes), various studies have estimated that it would take six months to three years to offset the carbon Impacts from the manufacturing process.

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