Thanks to a preponderance of empirical evidence, it is now clear that our climate is changing; the impacts of which can readily be seen on the nightly news. It appears we humans have literally altered our planet’s weather. In response, many individuals, companies and NGOs (non-governmental organizations) have pledged to reverse this degradation, largely through reductions in greenhouse gas (GHG – primarily CO2) emissions. While these initiatives are to be applauded, the inconvenient truth is that the challenge is far greater than the response, and much more change is needed. To ensure success, we must take a two-pronged strategy where our practices emit less carbon and our choices mindfully facilitate its sequestration.
In short, carbon sequestration is the process by which gaseous carbon (generally carbon dioxide, CO2) is stabilized into a solid (occasionally liquid) state. This transfer should be familiar to arborists, as it describes photosynthesis, the process by which plants utilize water and photonic energy to break apart CO2 molecules. This process releases the oxygen and blends the resulting byproducts into a simple sugar – the building block of cellulose and thus wood. (Figure 1)
Simply put, sequestration equals plant growth, and the pace of this growth is the rate of sequestration. This fact is important, as many oppose tree trimming and removal, suggesting that trees are the solution to climate change. This is factually true, but the story is a little more complicated.
Wood is indeed composed of sequestered carbon. However, if the tree is no longer growing (senescing), it provides no benefit to a carbon calculus. In essence, old trees are dying back at the same rate as they grow, and thus have reached a carbon equilibrium.
Carbon cycle and climate change
Planet Earth has essentially had the same amount of carbon for billions of years. That said, over time there have been significant fluctuations in how much of this element is within the biosphere/atmosphere (in the carbon cycle) versus in the lithosphere/pedosphere (underground). It may be helpful when trying to understand this cyclic process to use an arboricultural example.
Trees are essentially rooted props for green solar panels. These leaves (using sunlight as energy) capture carbon to use as a building block for plant structures. In the autumn, via abscission, leaves are cast off and rot. Rot is a decomposition reaction that releases CO2, making it again available for plants. This oxidative process is exothermic (releasing heat) and is chemically identical to combustion. (Figure 2)
For thousands of years (perhaps as many as 1 million), humans have used wood fuel for cooking and heating. In doing so, we are intrinsically involved in the carbon cycle. Despite the loud protestations of some, burning wood is a carbon-neutral process (recognized by EPA and DOE), because the fuel (the wood) was part of the carbon cycle and would have rotted (or burned) and released its carbon anyway.
By contrast, combusting fossil fuel releases carbon that was removed (via sedimentation and metamorphosis) from the carbon cycle long ago. This largely anthropomorphic (human) activity returns geologic carbon to rotation, bringing atmospheric carbon levels up and contributing to the effects of climate change. Geologic carbon, like my wife’s prom dress, is better left hidden.
Electric vehicles and climate change
This is a loaded issue. EVs are inherently more efficient than conventional vehicles by the simple fact that they lack radiators. Radiators are designed for the sole purpose of shedding thermal energy (heat). However, it is equally important to recognize that the electricity that powers EVs is far from green.
In 2022, only 12% of the total electricity consumed within the six New England states (VT, NH, ME, MA, CT and RI) was deemed “renewable” (a designation that includes waste-to-energy). That said, the grid becomes a bit greener with every solar panel and windmill commissioned. There is still a long way to go.
Electric vehicles and the future of arboriculture
Despite recent introductions of electric chassis by several major manufactures (Mack, Freightliner and others), the realities of arboricultural-vehicle duty cycles make adoption a challenge. Unlike most medium-duty truck applications, bucket trucks spend most of their service life in static operation. While this use may appear less energetically demanding than continuous driving, it still greatly exceeds available battery storage capacities. As a result, adaptive manufacturers, such as Altec, so far have chosen to pursue a hybrid design.
This approach (called Jobsite Energy Management, JEM, by Altec) combines an EV’s battery and drive systems with a conventional motor that functions as an onboard generator. Undoubtedly, as generation is intermittent, the majority of the duty cycles of a JEM-equipped truck will be quieter. However, this approach ensures that all job-site generation comes from diesel. At least shore power (plug in) contains a fraction (regrettably small) of renewable energy. Utilizing (when temperatures allow) a B20 biodiesel blend will mitigate this emissions impact.
Northern Tree Service embraces electric propulsion
Northern Tree Service in Massachusetts is keenly aware that its biggest clients are utilities. It is, therefore, especially merited for Northern to embrace electric propulsion. Accordingly, the company’s approximately 240 employee-owners are exploring how EVs could be integrated within their unique fleet. In its initial assessment, Northern has focused on products like the Ford Lightning and Rivian (R1T) pickup trucks. These pickups conform with functional expectations and have roughly 175 miles of realistic range. Northern is considering both for sales and safety managers.
Should additional daily range be needed, the Ford EVs can now be plugged into any rapid charger, including those branded by Tesla (per May 2023). Charging at such a station for 20 minutes can gain at least 100 miles of additional range. Northern also is exploring the purchase of electrically powered compact, or tracked, lifts.
Typically, these vehicles are “fueled” overnight, which presents a challenge, as many arboricultural pickup trucks are driven home by their operators. Ford has suggested that its residential charging stations (240v, $750 plus installation) are “smart” and can attribute the load to a corporate (i.e., not the home) meter and subsequent account. At press time, this functionality was not confirmed to the author’s satisfaction. Needless to say, this reattribution is technically possible, as it is simply net metering (solar power attributed to a distant meter/account) done in reverse.
One of the barriers to adoption for EVs is simply the cost of the vehicles. According to Altec, JEM-equipped, aerial-lift trucks for utility-line work are likely to command a hefty $290k sticker price. Ford Lightnings are also significantly more costly than their conventional equivalents, with the Pro trim package expected (yet to be released) to cost $60k to $65k.
That said, the federal and many state governments currently offer significant incentivization rebates. An eligible vehicle purchased in Massachusetts can receive as much as $11k in rebates ($7,500 federal and $3,500 state). It is also worth recognizing that despite recent increases in power prices (Massachusetts homeowners currently pay $0.32/kWh), e-propulsion is significantly less expensive per mile. Manufacturers will try to show this using MPGe as a metric. However, this very misleading index is best used to compare EVs. It is more difficult to compare between conventional and electric ownership costs.
In the model in Figure 3, I show that fueling a Ford Lightning is roughly half the price of an equivalent conventional truck. For a company truck that may cover 40,000 miles per year, this annual fuel savings can be more than $3,000. However, it is also worth noting that electric vehicles have fewer moving parts and do not require oil changes or any transmission maintenance. Every year, a company pickup truck is likely to have its oil changed monthly (40,000 miles/annum). Avoiding these 12 services and the associated downtime will likely save owners at least an additional $1,000.
In Massachusetts, commercial electric customers commonly pay $0.18/kWh for power. That is depending on their load characteristics subject to time-of-use pricing (similar to demand pricing). With the development of the solar sector and subsequent reductions in technology prices, it is often possible for businesses to further reduce their power costs by installing solar.
Naturally, installation of solar trades a power bill for a mortgage. In today’s electric marketplace, a mortgage is generally less expensive. This feasibility is influenced by federal (30% tax credit) and state incentives. Solar intensity also is a factor (Arizona has more sun than Oregon).
To successfully address climate change, we, as a society, must make a number of difficult changes. Some of these adjustments will revise how we condition buildings and move our vehicles. Electrification is likely to dominate these sectors, with heat pumps and EVs becoming ever more common.
Arboriculture is in the curious position of being responsible for millions of tons of clean waste wood (stored solar power). Recognizing that this material’s carbon will be unavoidably released, wood fuel used for heating presents a remarkably decarbonizing opportunity. If our industry chooses to organize, our waste material could play an important role in offering an alternative to electrification.
Jonathan T. Parrott, Ph.D., is a Massachusetts licensed forester, an ISA Certified Arborist and a TCIA Certified Treecare Safety Professional (CTSP). He also is director of safety, education and special projects with Northern Tree Service Inc., a 46-year TCIA member company based in Palmer, Massachusetts. His previous article on the topic of alternative-fuel work trucks, “Future Fuels in Arboriculture,” appeared in the May 2022 issue of TCI Magazine.