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Battery Electric

Background Battery Electric Vehicles (BEV) run on electricity stored in batteries and have an electric motor rather than an internal combustion engine. These are full size vehicles that drive like a regular fuel vehicle, but have substantial other benefits such as powerful smooth acceleration, great torque and a quiet drive. They can be charged anywhere, anytime, and at a much cheaper cost than fuel.
How It Works BEV drivers find charging to be easy and convenient, most charging occurs at a shop or home location and after normal hours like overnight. Imagine coming to work with a full tank each day. Fast charge stations even allow for a quick top-off for those who need an extended range during the day. There are public and workplace options for charging your vehicle as well.
Availability BEV’s are widely available in the medium duty class with a variety of ranges. Heavy-duty vehicles are common in the bus sector but still emerging in the tractor sector.
Cost BEV’s are about 4 times more efficient than a conventional vehicle so operating costs can be very low. By taking advantage of off-peak electricity rates you can dramatically lower your fuel cost. For example, paying $0.10 per kW is the equivalent of driving on fuel that costs less than $1 per gallon. The cost of upgrading electrical service can be considerable and careful management of demand charges is important.
Fueling There are three basic levels to charge any BEV, and since the adoption of a standard connector (J1772), every new BEV can be charged using any charging equipment with the standard connector. How long it takes to charge at each level depends on how far you have driven and the size of the battery. Charging speed is also governed by the size of the on-board charger and power lever of the charging equipment.
Level 1 charging uses a standard 120-volt plug. Level 1 charging provides a slow but steady charge and can work for smaller batteries in an overnight situation.
Level 2 charging requires 240 volt and is more common in the medium-duty vehicle sector where extra electricity is require to efficiently fill the larger batteries.
DC Fast Charging at 440-volt is a very fast way to fill and can provides a quick partial charge in less than an hour.
Benefits Battery electric vehicles are the cleanest technology available producing zero emissions. Even when accounting for power plant emissions, especially with the increasing number of renewables on the power grid, BEVs are much cleaner. Vehicles that are more efficient can make a big difference to society in terms of environmental benefits and reducing carbon emissions.

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Natural Gas

Background Vehicles fueled by fossil-based natural gas reduce smog-forming and greenhouse gas emissions. Natural gas vehicles are in widespread operation across all major classes of vehicles. Compared to conventional vehicles, natural gas vehicles with the latest commercial technology produce nearly zero emissions of PM and NOx and a modest reduction in GHG emissions of about 20 percent. Fuel is less expensive and widely available.
How It Works Natural gas is a mixture of hydrocarbons consisting primarily of methane, which is a simple molecule that burns very cleanly. The natural gas used in vehicles can be either compressed (CNG) or liquid (LNG) and stored in one or more high-pressure tanks on the vehicle. Natural gas engines are spark-ignited, like gasoline vehicles, and have spark plugs and a catalytic converter. Although performance is comparable to their diesel-fueled counterparts, range between fills is often slightly less (depending on tank size) and less powerful in the largest engine configurations. Benefits include less expensive fuel and wide availability.
Availability Natural gas is largely produced domestically in the United States, plentiful and projected to remain affordable into the future. CNG and LNG vehicles are widely available in the medium duty class with a variety of ranges and configurations. Heavy-duty vehicles are common in the bus and medium-duty sectors. There are even numerous heavy-duty tractor configurations currently available with more options slated in the coming years as near-zero technology becomes available in the largest engine configurations.
Cost The initial incremental cost of a CNG vehicle is typically higher than its diesel fuel counterpart, however, natural gas costs on average one-third less than conventional diesel fuel and there are often incentives to offset the higher price. Infrastructure upgrades may be required to fuel onsite as well as training for maintenance staff and shop modifications.
Fueling Natural gas infrastructure is well developed in the United States and there are over 1000 CNG refueling sites nationwide and more than 150 in California. Many fleets install on-site fueling. The Department of Energy's Alternative Fuels Data Center provides maps to refueling stations in the US for natural gas and other fuels.
Safety CNG/LNG vehicles are very safe and unlike diesel fuel, natural gas would dissipate up into the air because it is lighter than air in the event of an accident. The fuel storage cylinders used in CNG vehicles are much stronger than diesel fuel tanks and are subjected to a number of federally required abuse tests, such as heat and pressure extremes, gunfire, collisions and fires. CNG fuel systems are sealed to prevents any spills or evaporative losses.

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Background Hybrid electric vehicles (hybrids) combine an internal combustion engine with a battery and electric motor. This combination offers the range and refueling capabilities of a conventional vehicle, while providing improved fuel economy and often times lower emissions.
How It Works Hybrids come in various different configurations. Some designs can move the entire vehicle without the engine while other designs can offer standby power to operate vehicle equipment while the engine is off.
Propulsion can come entirely from an electric motor, such as in a series configuration, or the engine might provide direct mechanical input to the vehicle propulsion system in a parallel configuration system. A hybrid's efficiency and emissions depend on the particular combination of subsystems, how these subsystems are integrated into a complete system, and the control strategy that integrates the subsystems.
Availability Hybrids are commercially available in the medium duty class and being demonstrated in heavy classifications.
Cost Hybrids often cost more than their traditional counterparts due to cost of the battery, however this is not always the case. Also, you may be able to recoup the higher upfront cost by spending less each month on fuel and qualify for an incentive.
Fueling Today’s hybrid electric vehicles are traditionally refueled at a station while some vehicles can be plugged in to augment operations. As a result, refueling is the same as conventional vehicles, although generally required less often due to improved fuel economy.
Benefits The fuel economy benefits combined with the ease of ownership makes hybrid vehicles an attractive option for vehicle owners. Due to their internal combustion engine, hybrids will never be true zero-emission vehicles but can reduce greenhouse gas pollutants significantly. Cleaner and more efficient vehicles can make a big difference to society in terms of environmental benefits.

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Background Hydrogen fuel cell vehicles run on compressed hydrogen that is fed into a fuel cell "stack" that produces electricity to power the vehicle. A fuel cell is commonly used in combination with an electric motor and small battery to drive a vehicle - in a clean, quiet and powerful manner with only water as the byproduct.
How It Works A hydrogen fuel cell electric vehicle is powered by a “fuel cell” that consists of many single cells that are connected together and known as a fuel cell stack. Inside the stack hydrogen and oxygen from the air is chemically combined to release electricity and water. The electricity generated by the fuel cell stack powers the electric motor that propels the vehicle. A fuel cell stack produces power as long as fuel is available, similar to a combustion engine.
Availability Hydrogen is commonly made in large volumes for use in various industries and delivered via truck or pipeline. Usually hydrogen is made from either steam methane reformation of natural gas or via electrolysis from water using electricity. California continues to work on increasing production from renewable sources. Medium and heavy FCEV are being developed with several demonstration project statewide and California has been aggressively expanding stations throughout the State.
Cost The capital cost of a FCEV vehicle is significantly higher than its diesel fuel counterpart, however, higher efficiency and lower fuel costs (via the LCFS credit), and incentives can offset the high upfront price.
Fueling Many new hydrogen-fueling stations are being located at existing diesel fuel stations, which means that hydrogen dispensers may be placed adjacent to or on the same island as the diesel fuel dispenser. However, double check with a facility to ensure a commercial vehicle can be handled. Diesel fuel and hydrogen dispensers look similar but the nozzle and hose are actually different. The nozzles forms an airtight connection to the vehicle and the hose is narrow and feels cool to the touch as compressed hydrogen flows through it. California Fuel Cell Partnership: The CaFCP maintains a map of all hydrogen fueling stations planned and in operation in California.
Benefits A conventional combustion engine uses less than 20 percent of the chemical energy in diesel fuel, which means more than 80 percent of the fuel is “wasted.” In contrast, a fuel cell converts up to 60 percent of the chemical energy in hydrogen to drive the vehicle. Therefore, a fuel cell electric vehicle is potentially 3 times as efficient as traditional combustion vehicle and virtually pollution-free. Fuel cell electric vehicles achieve the beneficial characteristics of both conventional and battery electric vehicles. The combination of these desirable characteristics makes fuel cell electric vehicles an attractive advanced vehicle option for drivers that value long range, fast refueling, and zero-emissions.
Safety Fuel cell electric vehicles are safe or safer than conventional vehicles and held to the same strict requirements as conventional vehicles set by the Federal Government and standards development organizations and are designed to protect passengers and first responders in case of an accident. The fuel cell stack and battery pack are sealed in separate metal cases and electrically insulated from the vehicle’s metal body, plus there are a number of safety systems to prevent high voltage hazards. In addition, hydrogen is much lighter than air and quickly dissipates in the event of a leak.

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Background Vehicles fueled by propane, also known as autogas or LPG, are in widespread operation across all major vehicle classes. Propane gas is less expensive, plentiful and mostly produced domestically. It is stored as a liquid onboard a vehicle and easily vaporizes to burn cleanly while producing a reduction in GHG emissions of about 20 percent. Propane fuel vehicles are a potential alternative-fuel option in regions without natural gas infrastructure.
How It Works Propane is a mixture of hydrocarbon gases, predominantly propane and butane, and is a co-product from the production and refinement of natural gas and oil. The propane used in vehicles is compressed into a liquid and stored in one or more onboard tanks. As pressure is released, the liquid propane vaporizes and turns into gas that is used in combustion. Propane engines are spark-ignited, like gasoline vehicles, and have spark plugs and a catalytic converter. Performance is comparable to their diesel-fueled counterparts in all but the largest engine configurations. Fuel economy is slightly less than diesel because the energy content of propane on a per gallon basis is lower.
Availability Propane is largely produced domestically in the United States with some Canadian production. It is plentiful and projected to remain affordable into the future. LPG vehicles are widely available in the medium duty class with a variety of ranges and configurations. Heavy-duty vehicles are common in the bus and medium-duty sectors. Bi-fuel vehicles also exist with extended ranges.
Cost The initial incremental cost of a LPG vehicle is typically higher than its diesel fuel counterpart. However, propane costs less on average, which can lead to an attractive payback time. There are also costs associate for maintenance staff training and shop modifications. Compared to other alternative fuels, propane station are reasonably priced and some fleets choose to build an on-site location.
Fueling Propane infrastructure including production, storage, and bulk distribution capabilities is well developed in the United States. The Energy Commission estimates that there are more than 1500 locations in California where propane can be purchased for vehicles. Many fleets install a fueling station on-site or use a ‘wet hosing’ commercial fueling service. Fuel is stored and distributed as a liquid at relatively low pressures and fuels in minutes. Vehicle range is variable depending on tank size.

The Department of Energy's Alternative Fuels Data Center provides maps to refueling stations in the US for propane and other fuels.
Safety LPG vehicles have been in use since the 1950’s and there are almost 200,000 on-road propane vehicles in the United States. There are well established fire and safety codes that govern storage, handling, transportation and use to mitigates risks and ensures safe installations. Propane vehicles have passed rigorous crash testing and must meet the same safety standards as gasoline vehicles. Propane is non-toxic and has an odorant added during production to warn against leaks

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Renewable Diesel

Background California is trending toward increasing consumption of alternative transportation fuels in place of conventional petroleum-based diesel fuel and diesel fuels. This trend is primarily due to economic incentives and policies at the State and national level that incent the use of lower polluting, less toxic, and lower carbon intensity fuels in the commercial market.
How It Works Renewable diesel is an innovative diesel fuel replacement that is virtually indistinguishable from conventional diesel. The fuel is distinct from biodiesel but still derived from biological feedstock. Renewable diesel can be blended in existing fuel supplies or used as a ‘drop in’ fuel because it is chemically identical to regular diesel.
First generation biofuels are generally a product of fats or vegetable oils while second generation biofuels are made from cellulosic biomass that are harder to extract the required fuel. A series of physical and chemical treatments are required to convert cellulosic biomass to liquid fuels suitable for transportation. Other emerging fuel stocks include cellulosic sources like biomass from agricultural waste, non-food crops, other wood waste, and even from micro algae.
Availability Renewable diesel is compatible with existing fuel distribution systems. Blended renewable diesel can be distributed through modern infrastructure and transported through existing pipelines to dispense at fueling stations. In addition, the fuel is available at certain stations and is also commonly delivered onsite by mobile fuelers.
Cost The fuel is typically cost neutral when accounting for the Low Carbon Fuel Standard Credit.
California’s Low Carbon Fuel Standard (LCFS) is designed to reduce California’s dependence on petroleum, create a lasting market for clean transportation technology, and stimulate the production and use of alternative, low carbon fuels in California. The LCFS provides a framework that uses market mechanisms to spur the steady introduction of lower carbon fuels by establishing performance standards that fuel producers and importers must meet each year.
The LCFS credit value represents a source of additional revenues for low carbon intense fuel producers and distributors, who can sell credits generated by their fuel. The LCFS credit value can offset the higher initial costs of producing these fuels and is used to reduce the higher initial price of those fuels to enable them to compete with conventional fuels. The value added from the sale of LCFS credits depends on the fuel’s carbon intensity, the stringency of the annual standards, the LCFS credit price, and the volume of conventional fuel displaced.
Fueling Renewable diesel is not subject to blending limits like biodiesel. However, renewable diesel generally has mediocre lubricity and needs to be used in a lubricated mixture or have a lubricity additive added to the fuel.
Benefits Using conventional feedstocks, such as corn, these fuels provide carbon intensities about 25 percent lower than petroleum diesel fuel. With waste feedstocks, the carbon intensity can be as much as 80 percent lower than petroleum-based diesel fuel.
Safety Renewable diesel is very safe and pumped like ordinary diesel fuel. It meets specifications in ASTM D975. Renewable diesel is generally more homogeneous and does not exhibit the chemical variability of biodiesel.

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