A grown tree sequesters 48.5 pounds of carbon per year, and comparing this general average to 0.85 pounds of carbon offset per kWh of solar electricity, it is clear that removing some trees is acceptable from an emissions standpoint.
Is it worth cutting down a tree to install solar panels? This complex issue must consider carbon emissions, as well as the sustainability and value of nature.
An analysis by the European Environment Commission shows that a single tree sequesters 22 kilograms (48.5 pounds) of carbon in its physical structure every year until 3 trillion trees die and release the carbon in the form of methane. There are 100 to 400 trees per acre of mature forest, which can sequester 4,850 to 19,400 pounds of carbon per acre per year.
Keep in mind that these carbon sequestration figures only apply to mature trees with intact trunks. The carbon capture of shrubs and saplings is only a fraction of that of large mature trees, an important factor to consider when deciding whether to cut down trees.
When looking at carbon offsets from solar installations, the results depend on how each region generates electricity and the time period for which it is generated. Hydropower, which supplies most of upstate New York’s electricity, is much cleaner than the coal plants that supply about half of Nebraska’s electricity, so the latter’s solar installations offset far more emissions than their equivalent installations in the former’s upstate.
According to the U.S. Department of Energy’s Energy Information Administration, the average U.S. emits 0.85 pounds of carbon dioxide per unit of electricity generated. Thus, an average 400 W solar panel generating 1.5 kWh* per watt per year would offset 510 pounds of CO2 emissions.
*The output of solar panels varies widely by geographic area – panels installed in the south produce more electricity than those in the north.
One solar panel offsets the carbon equivalent of more than ten mature trees. A typical residential solar installation of about 7000 W can offset the carbon equivalent of more than 180 trees. An acre of solar panels with an installed capacity of 250,000 W can offset more carbon emissions than 6,500 trees.
So, based on carbon emissions alone, just one residential solar installation is worth more than a few trees. And one acre of dense solar panels offsets at least 16 to 65 times the carbon emissions of the same area of forest.
Another encouraging fact is that carbon offsets are not the end result of offsetting emissions from solar facilities. Solar installations installed on well-managed carbon sequestration land may eventually generate additional carbon offsets.
For example, the analysis showed that an acre of native forage plants beneath a solar facility could improve soil at a carbon sequestration rate of 1 ton per year, with carbon and other nutrients likely to accumulate for 12 to 15 years until the soil is fully saturated.
The researchers ran simulations of prairie grasses in the upper Midwest of the United States and found that native grass species as part of 10 GW of solar power capacity could sequester 129.3 tons of carbon per hectare; this is more than the agricultural farming or solar-turf scenarios, respectively. 65% and 35%.
So while we do need large tracts of uninterrupted natural environment in order to build a healthy environment that will support human survival for the next millennium, there are also net benefits in cutting down some trees in certain circumstances. .