by Paul G. Blystone, Sunnyvale, California, USA
People in developed countries throughout the world purchase and use power in similar fashion: electricity and natural gas for home usage and liquid petroleum fuel to meet transportation needs of automobiles, trucks, trains and planes.
The majority of electricity in the world is provided by power plants that burn carbonaceous material from underground sources-- principally coal and natural gas. Liquid petroleum for transportation purposes is provided by the refinement of a totally different underground material -- crude oil.
|World energy consumption, 1970-2025|
It is generally believed that emissions from power plant smokestacks and transportation vehicle tailpipes are the two most significant contributors to increased CO2 levels in the earth’s atmosphere from man-made sources. This is because they both convert carbon that was sitting quietly underground into combusted CO2 that continually accumulates and increases total atmospheric CO2 levels.
From the days of Thomas Edison and Henry Ford to the present time, electricity for homes and liquid fuel for transportation have been distinct and separate domains, with little cross-over between the two in terms of energy source, production, distribution, ownership, markets, economics, regulations and usage. But technology, marketing, and regulatory forces are at play that will inevitably mix these two energy markets together. Electricity to Wheels - Oil Replacing Technologies The blending of electricity and transportation energy began in earnest with Toyota’s wildly successful introduction of a hybrid car. The Prius was the first vehicle to demonstrate an oil-replacing technology on a large, commercial scale. Besides using petroleum energy from the gasoline pump, the automobile could now additionally be propelled using energy from stored electricity in batteries. While the first generation hybrid relied on self-recharging of the battery through regenerative braking, next generations will offer greater mileage from electricity through the use of larger, more energy dense batteries that will be recharged using electrical power from a wall plug. These so called plug-in hybrid vehicles, or PHEV, will further swing the energy pendulum from crude oil sources to electricity sources. The implications of this trend are three-fold:
- Automobile gasoline emissions will be replaced with emissions from power plants.
- More electricity will be required from power plants to fill growing electric transportation needs.
- Additional requirements will be placed on the electricity grid itself, because grid reliability becomes more important as the population begins to rely on it for transportation needs.
There are good reasons to believe that these prognostications will have a positive impact on the environment. A recent study indicated that a plug-in hybrid with a 20-mile all-electric range reduced average carbon emissions by about 60% per vehicle when compared to a conventional internal combustion car (source: The Environmental and Energy Study Institute). Another recent study finds that "off-peak" electricity production and transmission capacity could fuel 84 percent of the country's 220 million vehicles if they were plug-in hybrids. (Source: US Department of Energy - Pacific Northwest National Laboratory). This is because there is a great surplus of unutilized electricity during the nighttime hours when PHEVs would be “plugged in” for recharging. However, as more and more electricity is required for transportation needs, electricity grids will need improvements to make them more robust and “smart”. Intermediate Vision - Electricity and Alternative Fuels Make Good Partners
|Volvo C30 plug-in diesel hybrid concept car|
The beauty of the next generation PHEV is that if you forget to charge the battery or if you simply need to drive farther than the battery capacity, you still have a hybrid engine with liquid fuel in the tank. But since the majority of miles driven by PHEV owners will be powered by the battery, the amount of liquid petroleum purchased and utilized is greatly reduced. This alone reduces the number of barrels of crude oil required for general transportation purposes. Another intermediate step for PHEV can be the replacement of gasoline engines with diesel engines, as recent advances by major automobile manufacturers are making this a totally viable prospect. Diesel engines are inherently more efficient than standard gasoline engines, requiring less fuel for equivalent miles driven -- further reducing barrels of oil. Reducing barrels of oil for transportation purposes from today’s eye-popping numbers to a greatly reduced number opens up more realistic possibilities for emerging bio-fuel technologies. Depending on the bio-process and crop utilized, replacing crude petroleum with fuels derived from biomass can greatly reduce vehicle carbon emissions. An even more favorable CO2 balance occurs if bio-fuel manufacturing processes (which normally involve energy expenditure in crop growing, fertilizer and pesticide control, harvesting, fermentation, distribution) use power and material derived from bio-fuels and electricity from non-CO2 polluting sources. Recent advances in algae-to-biodiesel offer the prospect of very efficient and eco-friendly fuel production -- although it is still in early development. Algae proponents claim it is over 500 times more productive per acre than corn, while at the same time removing the negative consequences of soil-based bio-crops (competition-for-food conflicts, serious soil mining, erosion, and desertification issues). With capital investments running high, a variety of bio-fuel processes are racing for the pipeline. But while we wait for the winners to come on board, PHEV can significantly reduce CO2 emissions in the interim. Longer Range Vision -- CO2 Neutral This profound energy shift away from crude oil towards electricity generation can occur with a CO2 neutral/economically compatible vision in mind. Obtaining a CO2 neutral goal means the continual increase in electricity generation for transportation and home use from alternative and sustainable non-polluting sources such as geothermal, sun, wind, and water. Being economically compatible means offering new energy at close to today’s equivalent energy cost burdens, while at the same time using the involvement of existing public utility and industrial infrastructures. As opposed to other alternative energy ideas in the public eye, such as ethanol and hydrogen, the marriage of transportation and electricity does not require major infrastructure investments. The Toyotas and Fords of the world can still make and sell cars; power plants can still make and sell electricity; the grid can still carry electricity to homes and businesses; the Shells and Exxons of the world can still make intermediate liquid fuels, hopefully from bio (carbon neutral) sources, and sell it at today’s corner gas station. It is important to note that Shell is the world’s largest distributor of transport biofuels today. These same corner gas stations, while losing revenue from reduced liquid petroleum sales, might be able to replace that revenue by becoming distributors of electricity. High voltage recharging stations that quickly recharge newer generation batteries are a possibility. Advancing March of Electrons As today’s large engine-small battery cars move towards smaller engine-bigger battery offerings, it is clear that improvements in battery and ultra-capacitor technologies will be an important aspect of this vision. It will be prudent for regulatory agencies and manufacturers to create policies that mandate battery recycling in order to minimize any environmental impact from heavy metal mining and disposal.
|Tesla Motors All-Electric Roadster|
Ultimately, all-electric vehicles may emerge as a dominant force in the individual automobile marketplace. One can better understand what the advantages of an all-electric car have by looking at what they do not have. Electric cars don’t have: internal combustion engine, gas system (tank, cap, filter, pump, line, carburetor), spark system (plugs, wires, distributor), exhaust system (manifold, pipes, catalytic converter, muffler), air filter, oil system (oil, pump, filter, reservoir, cap), cooling system (radiator, coolant, pump, temperature sensors), crude oil emissions, nor does it need smog inspection or tune ups. These components are replaced with a bigger battery, electric motors, and an advanced battery management system. The environmental and ownership cost benefits to an all electric car are compelling, and its development needs to be watched closely in the coming years. Got Sunshine? Get Miles!!! I want to share one more vision that invokes the powerful concept of private ownership of energy. Today, dramatic advances are being made in solar photovoltaic (PV) technology. All across the globe, homeowners and commercial building owners are installing fixed solar PV systems. This rush to the sun has created a PV shortage, as solar cell manufacturers have not been able to keep up with the demand. In the United States, this demand will continue to grow in the near term because tax incentives and rebates make commercial adoption an extremely favorable economic choice, while also attracting middle to high-income homeowners. The return on investment (ROI) from an installed system is greatly improved when factoring in solar power for both home electricity and transportation. This means that replacing gasoline with PV energy is more economical than replacing electric utility charges, especially when crude oil prices rise. Although today’s homeowners are not considering this when asking for a PV system quotation (installers ask for utility bill copies, not gasoline expenses), this will quickly change as attractive and affordable PHEV and all-electric cars come to automobile dealer showrooms.
A large segment of this increased load on power plants from transportation needs can, and will, come from private owned, grid-connected PV systems. Homes, businesses, and parking structures can all provide the energy needed for automobile recharging. Electric parking stations at employer locations could potentially double the PHEV battery daily mileage range because it offers 2 recharge events per day -- one at night in the garage and one during the day while the vehicle is parked. Portable solar units (appliances) could offer consumers new possibilities and very real cost advantages. Since a large cost item of a solar PV system is related to installation, an appliance manufacturer could provide consumers with a stand-alone, ready to plug-in solar collection appliance. The unit simply “deposits” the energy to the grid during the day, only to be “withdrawn” to the vehicle at night. Alternatively, it could also send the energy to a storage system in the garage for later use by the vehicle. Such a device could be purchased at stores as simply as buying an outdoor gas grill.
At left is a diagram showing an estimated solar appliance footprint required for recharging a PHEV or all electric car battery using sunlight alone. The footprint assumes the following: - A solar cell efficiency of ~ 21% and peak power value of 16 watts/square foot. - An average annual sunshine profile of 5 hours/day (solar tracking increases this value). - An electrical consumption of 0.25 kWhr per mile by the vehicle battery (average value of published numbers from companies such as Tesla Motors). - Prius Dimension: 5.6 ft. wide x 14.5 ft. long The circles represent the radial footprints of a solar collector appliance equivalent to 25 and 50 PHEV driven miles/day respectively. Imagine a large picnic table solar umbrella as a model for the appliance. Of course, on cloudy days you use local utility power from your wall plug. While the technology is here today, the real challenge behind the concept will be to keep the price below equivalent lifetime gasoline costs. The cost of solar electricity is not simply the PV efficiency of converting sunlight to power, but also includes the “installed” watts per square foot costs, the material cost per square foot, and the lifetime usage. This means that raw material, manufacturing, and installation costs are all very important. If a car owner gets 25 miles per gallon and drives the car for 100,000 miles, the total gasoline cost is $12,000 (@ $3.00 US/gallon). This would appear to be a price target for a PV appliance. The appliance can be offered by the car dealer as an option at the time of the car purchase. Plus, you could take it with you when you move, and the device will probably last over 25 years. This means the cost can be amortized over multiple PHEV or electric car purchases spanning those 25 years. Today in California, rebates and tax incentives for such a grid-tied system would amount to over 30% of the total costs. Automobile manufacturers, electric utility companies, consumers, environmentalists, and politicians in developed countries should embrace and promote this concept of energy shifting. Replacing gasoline with electricity and/or sustainable bio-fuels, as well as replacing fossil fuel electricity generation with non-polluting sources (geothermal, sun, wind, and water) will all reduce carbon emissions. Conclusion While research and development on other emerging alternative energy solutions should continue (fuel cells, hydrogen, biomass), the aforementioned energy shift of electricity towards transportation needs can offer a significant step towards reducing the effects of climate change from man-made CO2 emissions within the near-term of 5-10 years. Further Reading: