Sustainable Transportation

AERREVA  H-Series

Self Charging Electric Vehicles

Abstract
All-electric vehicles (EVs) and internal combustion engine vehicles (ICEVs) both rely on secondary energy sources derived from the conversion of primary energy sources. Gasoline and diesel fuels are refined from crude oil, while electricity is predominantly generated from natural gas, coal, and nuclear power. These primary energy sources are unsustainable, with global reserves estimated to last only 57, 49, 139, and 90 years, respectively. As we continue to extract and convert these resources, the process becomes increasingly energy-intensive, resulting in a decline in the energy return on investment (EROI). This decline presents a significant risk of rendering some primary energy sources unviable in the near future.

While EV motors are significantly more efficient than their gasoline or diesel counterparts, the process of generating electricity for EVs is not without its inefficiencies and emissions. A staggering 60% of the energy used to produce electricity is lost as waste heat in power plants rather than being converted into usable power. When we factor in the full fuel cycle (FFC) of electricity, including AC/DC conversion losses during EV battery charging, the overall efficiency of both propulsion methods converges at around 20-30%. Furthermore, solar and wind farms, with capacity factors of only 28% and 35%, respectively, depend heavily on fossil-fueled power plants to ensure a consistent baseline power supply to consumers. The decline of energy resources underscores the need for vehicles that are not just sustainable but capable of operating directly from clean renewable energy sources without relying on the electrical power grid or unsustainable energy sources.

Sustainable Transportation Solution – AERREVA SC-EV concepts

Introducing AERREVA, a self-charging, off-grid all-electric vehicle concept (SC-EV) that emphasizes high efficiency and maximizes solar and wind energy production. Its onboard systems feature a concealed solar panel array that tracks the sun and a wind-tracking horizontal axis wind turbine (HAWT) subsystem.

Sun-tracking solar panels produce significantly more energy than stationary panels, especially in the northern hemisphere. The turbine subsystem features a telescoping tower and extendable blades that allow the rotor diameter to double in size, enabling the turbine to generate approximately four times the wind energy compared to when it is in its stowed position.

When not in use, the subsystems can be activated automatically when favorable weather conditions are detected or safely stowed during adverse conditions such as hail, extreme winds, or ice. Any surplus energy generated each day can be used to supply electricity to a home. Through net metering, homeowners can reduce their utility bills and earn renewable energy credits. Depending on electricity rates and weather conditions, these credits can range from approximately $100 to $500 per month.

Small wind turbines may generate less power than their larger counterparts, but they come with various advantages. One major benefit is that small turbines can be directly connected to battery chargers, which significantly reduces transmission losses that typically occur when electricity is sent over long distances from wind farms to consumers. Additionally, small turbines are easier and more cost-effective to maintain since wind farms are often located in remote areas.

For example, replacing a single blade on a large wind turbine can cost around $300,000, and replacing the gearbox can exceed $500,000. In contrast, smaller turbines can be installed much more closely together. Large turbines require up to 80 acres of space each to avoid interference from neighboring turbines. Moreover, smaller turbines operate at a lower blade tip speed, typically around 100 mph, compared to 180 mph for larger turbines. This lower speed reduces the risk of several issues, such as leading edge erosion, blade detachment, delamination, and structural failure, which can occur due to collisions with birds, lightning strikes, rainfall, salt, dust, insects, and other airborne particles.

The vehicle features a centerline battery compartment and tandem seating, which enhance stability and handling while providing protection for both passengers and batteries. The batteries are housed in a removable tray located at the rear of the vehicle, which not only supports the seat but also acts as a chassis support. This tray can accommodate various battery types, including lithium-ion, absorbent glass mat, and lead-acid batteries, the latter of which can be recycled more easily and cost-effectively than lithium-ion batteries.

The patent-pending AERREVA H-Series includes several models designed for different operating environments. Energy production estimates can be found on the solar and wind energy pages. Additionally, the new V-Series, which features a different type of wind turbine suitable for areas with shifting winds, is currently in development alongside other series.

The H-Series combines various configurations of wind turbines and solar panels. The horizontal axis wind turbine (HAWT) can be paired with either a tiltable solar array (T) or a non-tiltable solar array (S). The number of blades on the turbine rotor can be adjusted to optimize performance in different wind conditions. More blades generate greater torque in low wind conditions, while configurations with fewer blades, such as the two and three-blade versions, perform better in high wind conditions.

Even blade configurations (2, 4, and 6) can be neatly stored in the vehicle’s rear section, while the three-blade model (3H), which has the largest rotor diameter, can be stowed in a designated area. Additionally, a tracking solar array is most effective in regions with low sun angles, while a non-tilting solar array is preferable in areas with high levels of sunlight, such as regions near the equator.

The various configurations include:
TH – Tracking solar array with an HAWT fitted with an even number of blades.
SH – Extendable solar array (non-tracking) with an HAWT.
T3H – Tracking solar array with a three-blade HAWT.
S3H – Extendable solar array (non-tracking) with a three-blade HAWT.

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H-Series features
The vehicle features a centrally positioned cabin to enhance visibility, handling, and safety. It boasts a lightweight design and a small frontal surface area, contributing to greater efficiency. The battery pack, located at the center, is removable.

Additional features include large bypass air channels to improve aerodynamics, an extendable horizontal axis wind turbine subsystem, and a top-side solar array for charging while in motion, along with a retractable solar array subsystem. The design includes sloped top-side decks that facilitate rainwater runoff, an extendable anemometer for measuring wind speed and direction, and a spacious cabin door for easy entry and exit.

The vehicle also offers removable overhead canopies for open-air driving or emergency exits, a radiator to cool the battery pack, dampers to cool solar cells and enhance efficiency, and all-around crumple zones for occupant protection. The seats are easily removable, while the wide body provides stability and accommodates large solar and wind turbine subsystems. Additionally, most suspension components are shielded from the airstream.

For safety and convenience, the vehicle is equipped with side and rearview cameras, and it includes a spare tire stored in an outer wall compartment.

Battery Options
The battery pack, positioned centrally beneath the seats, is safeguarded by belly panels and chassis rails. It is compatible with various battery types, including Lithium-ion and Absorbent Glass Mat (AGM). The estimated range is 1,885 km (1,171 miles) for Lithium-ion batteries and 311 km (193 miles) for AGM batteries. Larger battery packs can extend the range but also add weight, which in turn increases rolling resistance. While lead-acid batteries perform better in subzero conditions, they provide less than a quarter of the energy (measured in Watt Hours per Kilogram) compared to Lithium-ion batteries.

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Generating Solar Energy

When the Sun sensor detects favorable conditions, it activates the solar array subsystem while parked.

Solar Array Capacity
The energy produced by solar cells is influenced by several factors, including the Sun’s strength and angle, air quality, and the efficiency of the solar cells. At sea level, the Sun’s energy density is approximately 1,000 watts per square meter. Solar cells with an efficiency of 22% can generate up to 220 watts per square meter. When all the solar arrays are combined and positioned horizontally, they can produce a total of 1,512 watts, equivalent to 7.56 kilowatt-hours (kWh) in a single day. This amount of energy can power the EV for daily trips of around 60 miles, assuming an energy consumption of approximately 6.714 kWh, or 122 watt-hours per mile, at a speed of 55 mph.

Additionally, using tracking systems can more than double energy production, particularly during winter months when the angle of the Sun is lower. The production estimates are based on an average of 5 kWh of solar energy per square meter, as indicated by solar energy maps from the U.S. DOE, National Renewable Energy Laboratory. The amount of solar energy varies by region, with Southwestern states receiving more energy per day compared to the Northeastern parts of the U.S.

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Generating Wind Energy

The vehicle’s wind turbine subsystem includes a telescoping mast and a rotor with extendable blades that can be stored in the rear section. An ultrasonic wind anemometer measures wind speed, duration, and direction to activate the turbine when favorable winds are detected while the vehicle is parked. The horizontal-axis wind turbine (HAWT) can be configured with either an even number of blades (2, 4, or 6) or a 3-blade version, which is the largest in the H-Series and produces the highest power output. Turbines with more blades provide greater torque in low wind conditions, whereas those with fewer blades enhance flow speed and perform better in high wind situations. When the vehicle is parked, the various HAWT subsystems can be activated if favorable wind conditions are detected.

3 Blade HAWT

6 Blade HAWT

The other blade configurations, a 4-blade, are not currently displayed.

Rotor Diameter	Wind Speed	Wind Speed
6 feet	15 mph -> 130 watts	30 mph -> 1,169 watts
9 feet	15 mph -> 294 watts	30 mph -> 2,640 watts
11 feet	15 mph -> 441 watts	30 mph -> 3,950 watts

Wind speeds of 20 mph or more in regions such as the Midwest and Great Plains can produce enough energy in 24 hours to power the EV for 500 miles, with even greater distances achievable in stronger winds. These mileage estimates are based on an energy consumption of approximately 6.714 kWh, or 122 watt-hours per mile, when traveling at 55 mph.

Solar Energy + Wind Energy
In a 30-day period, the solar panels and wind turbine can generate a total of 3,070 kWh of energy. This amount of energy is sufficient to charge an 80 kWh battery pack 39 times. For more information on renewable energy production, please visit our solar and wind energy pages.

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Energy is Money
Net billing, or net metering, with AERREVA electric vehicles can help reduce a household’s electricity bills. Electricity rates vary by state; for example, Hawaii has one of the highest rates, averaging 46.52 cents per kilowatt-hour (kWh), while Nebraska charges around 10.58 cents per kWh. By combining energy output from solar and wind sources, it is possible to generate approximately 1,068 kWh of energy every month. This can yield renewable energy credits worth around $113.00 in Nebraska and $496.83 in Hawaii. As energy demand increases and the transition to more expensive energy sources occurs, electricity prices are projected to rise.

Nationwide Wind Energy Potential
Small wind turbines have the potential to generate substantial amounts of energy. For instance, one million turbines operating in 20 mph winds can produce 28 million kWh of electricity, enough to power nearly one million homes for 24 hours. When wind speeds increase to 30 mph, the same number of turbines could supply energy to four million homes. Even at lower wind speeds of 15 mph, these turbines can still generate 10 million kWh daily, which is sufficient to power half a million homes.

(28 kWh x 1,000,000 = 28,000,000 kWh) (20 mph winds/24 hours).
(94 kWh x 1,000,000 = 94,000,000 kWh) (30 mph winds/24 hours).
10,000,000 kWh (10 mph winds/24 hours).

Energy Production Estimates
The estimates for solar and wind energy production did not take into account that an average car is parked approximately 95% of the time. Furthermore, the efficiency of converting DC to AC also has not been included in the estimate.

Development Stage
AERREVA H-Series EVs are currently in the early stages of development, from conceptual drawings to patent applications and prototypes. The next step is to build a functioning prototype. The vehicle and its wind and solar subsystems and methods are Patent Pending (Utility Patent Application) filed by DLA Piper LLP (US), a global company that provides intellectual property and patent services. They have been extremely helpful, providing information and guidance throughout the process.

Acknowledgments
The author acknowledges the National Aeronautics and Space Administration (NASA), the United States Environmental Protection Agency (EPA), the United States Department of Energy (DOE), the U.S. Energy Information Administration (EIA), and the National Renewable Energy Laboratory (NREL) for providing data.

Other AERREVA series
Currently in development are various AERREVA series and their variants. This includes a larger horizontal-axis wind turbine with a tower design, a larger solar array subsystem that can be attached to any variant, a new type of wind turbine that is more suitable for urban areas where wind direction changes frequently, and a wider cabin design for increased seating

LH – larger HAWT and tower.
LSP – larger solar array subsystem.
V Series – new type of wind turbine.
W Series – wider cabin.