Category Fuel Efficiency

• Battery technology is progressing slowly and advances in lithium-metal are not yet commercially available
• Federal EV battery incentives pertain to countries with US free trade agreements: Australia, Canada, and Chile
• Battery supply is constrained by metal mining and production is limited by complex and costly process technologies
• More research and product production methods are imminently needed

Battery production for electric vehicles should be a concern. For one, the US has neither the resources nor the production capacity to meet the demand of EV manufacturers. Second, as a national security concern, not having the requisite production infrastructure to support energy transformation leaves the US vulnerable to economic decline and energy price increases. Third, to navigate energy transformation it’s imperative to establish battery production for grid stability and resiliency, particularly when introducing renewable energies.

Currently, lithium-ion batteries are the core foundation for EVs and most vehicle manufacturers are planning to transition to all elective vehicles in the near future. California might ban the sale of new cars running only on gasoline by 2035. The issue is the production of EVs is inextricably linked to the availability of batteries that are limited by supply constraints in both battery metals and production capacity. Our focus is on battery supply chains and production.

Battery Supply Chains

The big issue around EV batteries is assuring an adequate supply of materials at a reasonable price.  To better understand the EV supply chain let’s look at the common raw materials namely metals and their associated costs. The four primary metals in a lithium-ion battery commonly used in most EVs are lithium, nickel, cobalt, and manganese. EV batteries use nickel-manganese-cobalt cathodes, with 60% nickel and 20% of cobalt and manganese.

The Possible Achilles’ Heel of EVs and Energy Storage – MarketScale

https://marketscale.com/industries/energy/can-the-texas-energy-grid-overcome-its-own-legacy-of-issues-for-the-winter-season/

MarketScale Podcast

Transportation Trends Pushing OEMs into New Mobility Territory – MarketScale

The worst global economic recession in since the Great Depression seems to be abating. Given the severity of the financial crisis, it might serve to review what impact the recession has had on oil consumption. In addition, what impact did the decline in oil consumption have on atmospheric CO2 concentration levels?

Since 2006, global oil consumption declined by 1.1 million barrels per day (BPD) from 85.2 in 2006 to 84.0 in 2009. Oil consumption in the US declined 9% to 18.8 million from 20.7 million BPD in 2006. Europe experienced a decline of 7% over this same period with a drop of 16.5 million to 15.2 million BPD. However, over this same period, oil consumption in China and India increased 16% and 13%, respectively. This data was complied from the US Department of Energy Information Administration (EIA) and is displayed in the following charts.

To measure how significant the impact has been, the following charts provide some insights in evaluating how deteriorating world economies may have impacted oil consumption and secondly, whether reduced oil consumption has mitigated heightened CO2 levels.

Figure 1 Global Oil Consumption
Source: EIA

From Figure 1, the impact of the global financial crisis is depicted with the decline in global oil consumption. When a comparison is applied to oil consumption between the US China, and India, the relative drop in oil consumption is less discernable.

Figure 2 US, China, and India
Source: EIA

Figure 2 provides a summary of oil consumption of the US, China, and India. A measurable decline in oil consumption can be seen, but only in the US market.

Figure 3 China and India
Source: EIA

Figure 3 demonstrates the steady and pronounced growth in oil consumption for China and India. Despite the global financial crisis, oil consumption significantly expands in China and India due to secular growth from rapid industrialization in both countries. When measured with respect to the European market, China and India have grown from 15% of the oil consumption rate of Europe in 1980 to over 74% of the consumption level in 2010.

Figure 4 CO2 Levels
Source: NOAA

With the decline in global oil consumption, perhaps a positive benefit would be a fall in CO2 levels. The atmospheric CO2 readings in part per million (PPM) where taken from the National Oceanic and Atmospheric Administration (NOAA) from the Mauna Loa CO2 Levels monthly measurements. Figure 4 illustrates the average annual atmospheric CO2 concentration readings in Mauna Loa, Hawaii from 1980 through 2010.

The bottom line is even while global oil consumption declined during the recession, growth in China and India remained unabated and subsequently, CO2 concentrations in the atmosphere continue at elevated levels.

In memory of Jamie Kotula – loved by family, friends, teammates, and school.

A combined heat and power system (CHP) is the cogeneration or simultaneous generation of multiple forms of energy in an integrated system. CHP systems consume less fuel than separate heat and power generating systems. According to the Environmental Protection Agency in their Combined Heat and Power Partnership report, (EPA), CHP systems typically consume only three-quarters the amount of energy separate heat and power systems require. By combining both heat and power into the same energy systems, efficiency gains for the total system. Heuristically, high temperature and high pressure fuel ratios results in higher efficiency systems. In addition, the thermal energy produced from the CHP system could be used to drive motor applications or to produce heat, steam, and hot water.

As an initial step to reducing greenhouse gas (GHG) emissions, natural gas turbines could improve overhaul efficiency of 65-80%. In addition, the CHP offers lower greenhouse gas (GHG) emissions in comparison to conventional standalone systems. Gas turbines CHP systems operate under a homodynamic principle called the Brayton cycle. The design characteristics of a CHP gas turbine provide: 1) high electric and total system efficiency; 2) high temperature/quality thermal output for heating or for heat recovery steam power electric generation; 3) offer options for flexible fuels such as propane, natural gas, and landfill gas; 4) high reliability with 3-to-5 years before overhaul running 24/7; and 5) significantly lower GHG emissions.

Figure 1 Gas Turbine CHP System

Figure 1 demonstrates the mechanics and variables of a CHP system. In summary, the CHP technology enables the supply of efficient heat and power while minimizing GHG emissions. Total CHP efficiency is defined as the sum of net power produced plus the thermal output used for heating divided by total fuel input.

The use of methane (natural gas) as the main fuel for the CHP system offers advantages because methane offers the highest hydrogen-to-carbon ratio among fossil fuels, thereby, combusting with the lowest GHG emissions. According to EPA data, the emissions NOx particulates from gas turbines ranges between 0.17-to-0.25 lbs/MWH with no post-combustion emissions control versus 1.0-to-4.2 lbs/MWH for coal fed boilers. The carbon content of natural gas is 34 lbs carbon/MMBtu in comparison to coal at 66 lbs of carbon/MMBtu.

There are two valuable metrics used to measure efficiency for CHP systems. One is the total system efficiency which measures the overall efficiency of the CHP system including heat and electric and the other is the effective electric efficiency which is useful in comparing the CHP electric production versus grid supplied power. These two metrics, the total system and effective electric efficiencies are important for evaluating CHP system. The following provides a guideline foe measuring these two efficiency metrics and can be found at EPA – Efficiency Metrics for CHP Systems

Figure 2 CHP Efficiency

The economics of the CHP system depends on effective use of thermal energy n the exhaust gases. Exhaust gases are primarily applied for heating the facility and could also be applied to heat recovery steam generators (HRSG) to produce additional electric power. The total efficiency of the CHP system is directly proportional to the amount of energy recovered from the thermal exhaust. Another important concept related to CHP efficiency is the power-to-heat ratio. The power-to-heat ratio indicates the proportion of power (electrical or mechanical energy) to heat energy (steam or hot water) produced in the CHP system. The following provides an overview of the economics of a CHP system.

Figure 3 CHP Economics

Figure 3 illustrates the economics of a CHP system in comparison to competing energy sources. While the CHP does not have the low cost of coal in producing electric, the economic value of reducing GHG emissions is quite significant and beyond the scope of this article. However, natural gas prices remain below that of oil and better ways of capturing heat exhaust will further improve CHP efficiency. The bottom line is that natural gas produces less GHG emissions than coal or oil therefore; businesses should consider the benefits of CHP as a source of heat and power.

The development of an energy efficiency strategy incorporates analysis of energy expenditures and energy consumption. The energy strategy must incorporate dynamics between costs, budgets and the consumption of energy including the monitoring of kilowatt-hours (KWH) of electricity and liquid hydrocarbon fuels consumed. By analyzing both the financial and the energy consumption components we are better positioned to frame the scope of the energy efficiency projects.

We start with a comprehensive energy audit analyzing energy consumption and expenditures. After determining which activities offer the fastest, cheapest, and greatest economic impact we are then able to define the scope of energy efficiency projects. The next step in the energy strategy process is to assess, rank and specify energy saving opportunities. At this phase, we have a broad understanding of the scope of energy efficiency projects within the appropriate budgetary considerations.

Conduct Energy Audit and Analyze Energy Spending

Upon analysis of the energy expenditures and the appropriate budgetary considerations, we commence with an energy audit to examine the dimensions of energy consumption. The energy audit establishes an energy efficiency baseline for buildings and vehicles. In the energy audit, energy consumption is measured by source and activity using monitors attached to branch circuits, gas pipes, and fuel lines. In this manner, energy consumption is evaluated from a financial and physical perspective and baseline usage patterns are established for electricity and other fuels.

During the energy audit, an analysis of energy intensity is measured. For buildings, energy consumption is measured in kilowatt-hours per square-foot to identify which activities consume the most energy. The energy intensity measurements are then ranked by consumption activity and compared to actual energy expenditures.

The purpose of the energy audit is to establish a baseline of energy consumption and the energy intensity associated with each building, department, vehicles, and/or activity usage category. By constructing an effective energy efficiency strategy that identifies and measures energy demand by activity, a better understanding of economic- and financial-impact is established. The critical component to the energy audit is measurement and verification were wireless Internet-based energy monitoring provide data before and after energy efficiency projects commence. The energy audit and energy monitoring systems together with financial analysis of energy consumption serve as the framework to rank and assess energy efficiency projects.

Heuristically, energy consumption in buildings is tied to lighting; and heating, cooling, and ventilation systems see Energy Intensity . The following chart, Figure 1 serves to illustrate which activities contribute most to energy consumption in buildings.

Figure 1 Kilowatt-hours (KWH) per Square Foot

According to information provided by the DOE, lighting, cooling and ventilation alone account for nearly two-thirds of all energy consumption in a building. For perspective, electric energy demand is increasing at an annualized rate of 1.6%. According to the Energy Information Administration (EIA), demand for electricity grew 21% between 1995 and 2006.

The energy consumption audit provides a means to assess which activities should be further analyzed for energy efficiency projects. The baseline energy usage measured in KWH per square foot serves as the framework to evaluate that locations and activities could benefit from lighting retrofits, equipment upgrades, structural improvements, and energy monitoring systems.

As a consequence of increasing energy consumption in buildings, electric generation relies extensively on hydrocarbon fuels that carry adverse environmental effects. Figure 2 illustrates the proportion of coal and other hydrocarbon fuels that are used to generate electricity in comparison to renewable energy sources. Coal still accounts for nearly half of all electric generation while contributing the most in terms of harmful emissions such as carbon dioxide, nitrous oxide, and sulfur dioxide.

FIGURE 2: Electric Generation Method

As part of the energy audit process for buildings, an energy consumption analysis of lighting and HVAC systems is evaluated along with the building’s insulation R-Value (resistance to heat flow where the higher the R-value, the greater the insulating effectiveness). In addition to lighting and HVAC systems, specialized equipment may also account for large energy demand. During our energy audit, we plan to identify and measure energy usage of special equipment in order to construct energy efficiency initiatives with clearly defined and measurable energy reduction targets.

Energy efficiency for transportation vehicles is one of the most significant factors to manage. The fact that there are no real substitutes for oil in the transportation industry illustrates two important points: 1) structural changes to driving patterns are required to see appreciable changes to oil consumption and 2) government authorities are vulnerable, with no readily available substitutes for oil, supply disruption could negatively impact transportation systems. Therefore, we emphasize fuel management systems for fleets and vehicles that monitor fuel consumption and efficiencies. DOE studies have indicated that changing driving habits could improve fuel efficiency by up to 30%.

Vehicle mounted devices that integrated fuel consumption feedback as the vehicle is driven promotes higher fuel efficiency. These off the shelf products are cost-effective, offering payback in months that dramatically improves fuel efficiencies. Aside from routine tune-ups, limiting weight, and checking tire pressure, augmenting driving patterns through gauges that provide feedback on fuel efficiency make the difference in saving energy.

In most situations, fuel management systems can be installed without significant mechanical aptitude. The ScanGaugeII from Linear-Logic is useable on most vehicles manufactured after 1996 including Gas, Diesel, Propane and Hybrid Vehicles and are designed to be installed by the consumer with plug-and-play instructions.

Identify and Measure Energy Demand by Activity

From the Energy Audit, the energy intensity of targeted buildings and fuel efficiencies of official vehicles are established. In buildings, it’s the lighting and heating, ventilation, and cooling that comprise the bulk of energy consumption.

Heating, ventilation, and cooling represent a significant portion of energy consumption in buildings and are a priority target for energy analysis. The Seasonal Energy Efficiency Ratio (SEER) is employed as an assessment of the equipment and analyzed in conjunction with building insulation. The efficiency of air conditioners is often rated in SEER ratio, which is defined by the Air Conditioning, Heating, and Refrigeration Institute and provides a standard unit measure of performance. The higher the SEER rating of a cooling system the more energy efficient the system is. The SEER rating is the amount of BTU (British Thermal Units) of cooling output divided by the total electric energy input in watt-hours.

For heating systems in a building, Annual Fuel Utilization Efficiency (AFUE) is used to measure and compare the performance of different systems. DOE studies have indicated that even with known AFUE efficiency ratings, heat losses defined as idle losses contribute to degradation in heating system efficiency,

To analyze energy consumption of heating and air conditioning systems (HVAC), we evaluate the building’s R-Value in comparison to the energy efficiency of the current heating and air conditioning systems. The energy demand evaluation includes a cost-benefit analysis comparing options in either HVAC system upgrade and/or improvements to the building’s insulation R-Value. By comparing the buildings R-Value in conjunction with HVAC efficiency performance, projects offering the greatest cost effectiveness are identified. The building’s R-Values can be measured using FLIR Systems infrared camera and software system. In this manner, the replacement cost of an HVAC system and costs to improve the building’s R-Value are analyzed to measure economic benefits. This information will allow the building owner to make an informed decision on whether any energy efficiency investment into HVAC upgrade or improvement to R-Value demonstrate economic benefit, i.e. positive financial return.

Consideration for heating and cooling systems upgrades are assessed by equipment SEER and AFUE ratings, installation costs, and efficiency payback. After equipment assessment is complete, proposals will be provided along with estimates for upgrade costs and payback analysis.

Benchmark and Analyze Energy Intensity

After conducting the energy audit, and compiling data on energy usage by activity category, we benchmark and analyze energy projects offering the greatest opportunities. As illustrated in Figure 3, energy efficiency for lighting systems can be substantially improved by retrofitting legacy light fixtures with higher efficiency fixtures and bulbs.

The energy audit and analysis provide the framework to evaluate energy efficiency projects. By analyzing energy consumption and the economic benefits associated with the energy savings projects, the most efficient and economically beneficial initiatives are identified and ranked.

FIGURE 3: Energy Savings in KWH per Square Foot Figure 1 Kilowatt-hours (KWH) per Square Foot

Establish Measurable Goals and Objectives

To establish relevant goals and objectives we are evaluating projects that are adhering to the SMART goal approach: specific, measurable, attainable, realistic and timely. Energy efficiency gains are most pronounced with lighting retrofits and energy monitoring in buildings in buildings and energy monitoring in vehicles.

After conducting an energy audit, analyzing energy consumption activities and the economics of energy efficiency projects, realistic and achievable energy savings goals are defined. Key performance metrics for energy savings are defined for buildings and vehicles. Key performance indicators are established for each project. For example, KWHs saved are defined for lighting retrofit projects, efficiency improvements for HVAC system upgrades, R-Value improvements for building insulation, and MPG gains for vehicles.

For each energy savings project, timelines are established with clearly defined milestones. Energy projects are presented with costs; expected energy savings measured in energy and dollar units, cost benefit analysis, and timelines.

Architect the Deployment of Energy Monitoring Systems

One of the first energy initiatives to consider in any energy savings project is the installation of an energy monitoring system for vehicles and buildings. Energy monitoring systems demonstrate the fastest and most economical pathways to achieving energy savings.

Energy monitoring systems for motor vehicles also demonstrate positive economic returns and real energy savings. The $180 energy-monitoring device with 10% fuel efficiency gain achieves breakeven at 14,500 miles with gasoline costing $2.50 a gallon.

Evaluate Feasibility of Renewable Energy Projects

Renewable energy projects such as solar and wind energy systems are often costly with long payback periods. Without tax incentives and grants, renewable energy projects are unable to demonstrate positive financial returns. However, utility rates for electric are expected to increase, improving the case for renewable energy projects. To improve the viability of alternative energy projects, energy efficiency projects such as lighting retrofit serve to lower energy consumption and therefore enhance the feasibility of solar and wind energy projects.

The precipitous drop in oil prices may not hold for long. Speculators and fears of oil flow disruptions drove oil prices to an all time high of $145.16 on July 14, 2008 and is now down to $49.50 in November 20, 2008. Now the fear has shifted to the economy where deteriorating fundamentals suggest demand for oil will abate, at least in the near term. However, if history is any guide, demand for oil should be influenced by both structural changes such as consumers driving more fuel-efficient motor vehicles and cyclical factors such as the state of the economy.

Figure 1 US Historic Oil Imports

To get an understanding of the impact that both structural and economic factors had in reducing the demand for oil is to look at oil import from 1978 to 1988. Figure 1 illustrates the US demand for oil during the last major economic recession. The Oil Shock of the 1970’s severely impacted the US economy and the term stagflation captured our attention while interest rates reached exorbitant levels. From 1979 to 1982, US oil imports decline by 46% as the oil embargo of 1973 led to structural changes in oil consumption. US oil imports, as measured by the Energy Information Administration in U.S. Crude Oil Field Production (Thousand Barrels per Day) demonstrated a significant decline as a result of changing driving habits as fuel efficient import vehicles encroached on the domestic auto makers. The US consumers opted for foreign vehicles demonstrating higher fuel efficiencies and MPG entered our lexicon. These economic and structural changes dramatically reduced the demand for oil and subsequently, oil prices fell. It was not until 1985 before oil imports began to increase.

What’s missing from this analysis is the fact that during this period the US accounted for 27% of total world oil demand. . According to the Energy Information Administration (EIA), in 1980, China and India accounted for 2.8% and 1.0%, respectively, of the global demand for oil. In 1986, China and India increased their oil demand to account for 3.2% and 1.5% of the world market, respectively, an increase in oil demand of 57% for China and 44% for India.

In 2005, China and India account for 8.0% and 2.9% of global oil demand while US dropped to 24.9% of global oil demand. While even China and India are not immune to the current blissful economic environment, when the global economy does improve, their demand for oil will more than negate any structural changes the US consumers make in their driving habits. The demand for oil should continue to grow as an economic recovery ensues thereby leading to an increase in oil prices.

Figure 2 China and India Oil Consumption

Figure 2. illustrates the rapid rise in the demand of oil from China and India. From 1980 to 2005, demand for oil increased 280% in China and 125% in India. Despite the improving fuel consumption in the US, the global oil market is more apt to be impacting from the growth in developing countries than conservation in the US.

The bottom line: don’t remain complacent, strive for energy efficiency and invest into alternative energies.

For further reading on oil prices please refer to
oil price analysis .

World oil demand continues to rise despite efforts to limit demand. Renewable energies such as solar and wind have the potential to limit our dependence on hydrocarbon fuels, but one issue remains prominent – storing energy. While the sun provides radiation for solar and generates wind, when its cloudy or dark we are unable to produce solar energy. One must provide a means to store that energy for when it is needed. Fuel cells enable energy conversion and fill a reliable role in alternative energy strategies.

A chart compiled by Wasserstoff-Energie-Systeme GmbH (h-tec) provides an easy to understand depiction of how fuel cells integrate with solar and wind energy solutions. Fuel cells provide the enabling technology that allows hydrogen to serve as the storage and transport agent. The solar energy that is produced during the daylight hours is used in an electrolyzer to produce hydrogen that in turn, is then used to operate the fuel cell producing electricity at night when it is needed. This process is called the solar-hydrogen energy cycle. Figure 1 illustrates the importance of energy storage in adopting alternative energies.

Figure 1 Solar-Hydrogen Energy Cycle

Demand for oil and hydrocarbon fuels continues to grow despite effort to conserve. Total Petroleum Consumption shows increasing oil demand from China and India while demand in the U.S. grows at a slower pace. With improving efficiencies and lower production costs, fuel cells could provide a solution to our appetite for oil in motor vehicles. Figure 2 describes how fuel cells and electrolyzers (fuels running in reverse) work.

Figure 2 Fuel Cells

Fuel cells are devices that convert chemical to electrical energy – in essence; it’s an electrochemical energy conversion device. In the chemical process of a fuel cell, hydrogen and oxygen are combined into water, and in the process, the chemical conversion produces electricity. In the electrolyzer, an electrical current is passed through water (electrolysis) and is the reverse of the electricity-generating process occurring in a fuel cell.

Hydrogen fuel cells offer tremendous opportunity for storing and transporting energy enabling broad applications for home, business, motor vehicle and large-scale energy projects. The follow provides a review of current technologies applicable to hydrogen fuel cells. Factors to consider in using hydrogen fuel cells include operating efficiency, operating temperature range, and material used for the electrolyte (the catalyst that separates hydrogen) and fuel oxidant (that transfers the oxygen atoms).

Figure 3 Hydrogen Fuel Cell Technologies

One of the most practical fuel cell technologies for motor vehicle use include Proton Exchange Membrane (PEM) because it operates at normal ambient temperatures and offers high electrical efficiency. There are several useful web sites that illustrate the benefits of hydrogen fuel cells. h-tec and the National Renewable Energy Laboratory provide some very useful information on hydrogen fuel cells.

We are also seeing progress on fuel cell vehicles that could ultimately ameliorate are demand for oil, if not eliminate it entirely, all with no carbon dioxide or other harmful emissions. We see most major automakers developing hydrogen powered fuel cell vehicles. GM is making progress introducing several models using GM’s Fuel Cell Technology.
Honda’s experimental hydrogen refueling station in Torrance, CA uses solar to produce hydrogen for their hydrogen fuel cell vehicle Honda’s FCX .

The bottom line is that the availability of cheap oil is on the decline and without further research on alternative energies we may find the global economy in a very tenuous position. Further research into solar and hydrogen fuel cells could significantly reduce our dependence on oil.

From the Industrial Revolution we learned that economic growth is inextricably linked to energy and as a result, our future is dependent upon equitable access to energy. When the Stourbridge Lion made entry as the first American steam locomotive in 1829 it was used to transport Anthracite coal mined in nearby Carbondale, PA to a canal in Honesdale that in turn linked to the Hudson River and onto New York City. Coal fueled the growth of New York and America’s Industrial Revolution because coal was cheap and more efficient than wood.

Advances in science and technology gave way to improvements in manufacturing, mining, and transportation. Energy became the catalyst to industrial growth. Steam power such as Thomas Newcomen’s steam powered pump in 1712 developed for coal mining and James Watt’s steam engine in 1765 were initially used to bring energy to market.

In terms of heating efficiency, coal at the time offered almost double the energy, pound for pound, in comparison to wood. Energy Units and Conversions KEEP Oil offers higher energy efficiencies over coal and wood, but as with most hydrocarbon fuels, carbon and other emissions are costly to our economy and environment.

With rapid growth in automobile production in the U.S., oil became the predominant form of fuel. According to the Energy Information Administration, in 2004 the U.S. spent over $468 billion on oil.

Figure 1 U.S. Energy Consumption by Fuel

We all need to become more conversant in understanding energy costs and efficiency and as a corollary, better understand the benefits of renewable energy such as solar, wind, and hydrogen fuel cells. A common metric we should understand is the kilowatt-hour (KWH) – the amount of electricity consumed per hour. The KWH is how we are billed by our local electric utility and can be used to compare costs and efficiency of hydrocarbon fuels and alternative energies.

One-kilowatt hour equals 3,413 British Thermal Units (BTUs). One ton of Bituminous Coal produces, on the average, 21.1 million BTUs, which equals 6,182 KWH of electric at a cost of about $48 per short ton (2,000 pounds). That means coal cost approximately $0.01 per KWH. To put that into perspective, a barrel of oil at $90/barrel distilled into $3.00 gallon gasoline is equivalent to 125,000 BTUs or 36.6 KWH of energy. Gasoline at $3.00/gallon equates to $0.08 per KWH. So gasoline at $3.00 per gallon is eight times more expensive than coal.

Is oil and gasoline significantly more efficient than coal? Let’s compare on a pound for pound basis. A pound of coal equates to about 10,500 BTUs or approximately 3.1 KWH per pound. A gallon of gasoline producing 125,000 BTUs weighs about 6 pounds equating to 6.1 KWH per pound (125,000 /3,413 /6). While gasoline is almost twice as efficient as coal, coal’s lower cost per KWH is why it is still used today to generate electric.

The Bottom Line: the economics of energy determines its use – coal still accounts for approximately half of our electric generation because it has a lower cost than other fuels. However, there are two factors to consider 1) the cost of carbon is not calculated into the full price of coal or other hydrocarbon fuels and 2) the cost of conventional fuel is calculated on a marginal basis while alternative fuel costs are calculated on a fixed cost basis. Meaning the cost of roads, trucks, and mining equipment is not factored into the price of each piece of coal, only the marginal cost of producing each ton of coal. For solar, hydrogen fuel cells, and wind energy systems, the cost to construct the system is factored into the total cost while the marginal cost of producing electric is virtually free. We need a framework to better measure the economics of alternative energy. The impact of carbon on our climate and global warming are clearly not measured in the costs of hydrocarbon fuels nor is the cost of protecting our access to oil such the cost the Iraq War.

Despite the carbon issues surrounding coal, (coal has higher carbon-to-hydrogen ratio in comparison to oil or gas) coal is more abundant and therefore is cheaper than oil. As electric utilities in 24 states embrace alternative energies through such programs as Renewable Portfolio Standards (RPS), perhaps the benefits of alternative energies will begin to combat the negative economics of hydrocarbon fuels.

Ethanol may emit less CO2 and help reduce the demand for foreign oil in the short term, but ethanol and in particular, corn-based ethanol raises food prices, is less efficient than gasoline, diesel, and biodiesel, and is not a substitute for oil.

According to research compiled by National Geographic Magazine , the energy balance of corn ethanol, (the amount hydrocarbon fuel required to produce a unit of ethanol) is 1-to-1.3 whereas for sugar cane ethanol the ratio is 1-to-8. This suggests corn-based ethanol requires significantly more energy to produce than sugar cane ethanol. Corn ethanol is only marginally positive.

A major issue with corn ethanol is its impact on corn prices and subsequently, food prices in general. It is the price of oil that is impacting the price of corn because nearly all ethanol produced in the U.S. is derived from corn. Therefore, corn prices are inextricably linked to oil prices as well as to the supply and demand of corn as food and feedstock. Corn Prices while volatile and impacted from weather and other variables appear to follow the rising price of oil as illustrated in Figure 1. In turn, corn prices are also influencing other commodity prices where corn is used for feed for livestock.

The rising motor vehicle usage in China and India is escalating the already tenuous situation in the oil markets. With ethanol tied to oil prices we are beginning to see corn prices exacerbate the inflationary pressures at the retail level. Over the last year consumers are paying more for food with large increases in the prices of eggs, cereal poultry, pork, and beef which are tied to corn.

Figure 1 Corn Prices

Senate legislation for Renewable Fuels Standard calls for ethanol production to increase to 36 billion gallons by 2022 with 21 billion derived from as cellulosic material such as plant fiber and switchgrass . Corn is expected to comprise 42% of the ethanol production in 2002 from virtually all today. The fact is that ethanol production at its current level of 6 billion gallons equates to only 4% of our gasoline usage and is already impacting food prices. Gasoline consumption in 2005 amounted to 3.3 billion barrels or 140 billion gallons. Current estimates put gasoline consumption at 144 billion gallons a year in 2007. Even if vehicles could run entirely on ethanol, there is not enough corn harvest to substitute our demand for oil. We need a cohesive and coordinated effort using multiple technologies to develop alternative energies to reduce our dependence on foreign oil.

Performance

According to Renewable Fuels Association ETHANOL FACTS:
ENGINE PERFORMANCE, ethanol offers higher engine performance with octane rating of 113 in comparison to 87 for gasoline and has a long history in the racing circuit. In 2007, the Indy Racing League, sponsors of the Indianapolis 500 started using ethanol in racecars. However, the higher engine performance may come at a cost of lower fuel efficiency.

Table 1 Specific Energy, Energy Density & CO2

Efficiency

Gasoline offers 56% higher energy efficiency (specific energy) over ethanol as measured by kilo-joules per gram (kj/g). (As a reference: 1 kilowatt-hour = 3,600 kilojoules = 3,412 British Thermal Units) Biodiesel with 35 kj/g is 33% more energy efficient than ethanol at 24.7 kj/g.

In terms of energy density, ethanol would require larger storage capacity to meet the same energy output of gasoline diesel, and biodiesel. Ethanol requires a storage tank 48% larger than gasoline and 41% larger than diesel for the same energy output.
Please see Hydrogen Properties and Energy Units

For a quick review of Specific Energy and Energy Density – (Molecular Weight Calculator) the specific energy of a fuel relates the inherent energy of the fuel relative to its weight and is measured in kilo-joules per gram.

CO2 Emission

The molecular weight of CO2 is approximately 44 with two oxygen molecules with an approximately weight of 32 and one carbon atom with a weight of 12. During the combustion process, oxygen is taken from the atmosphere producing more CO2 then the actual weight of the fuel. In the combustion process a gallon of gasoline weighing a little over six pounds produces 22 pounds of CO2.

CO2 emission is a function of the carbon concentration in the fuel and the combustion process. During combustion ethanol produces approximately 13 pounds of CO2 per gallon. Gasoline and diesel produce approximately 22 and 20 pounds per gallon, respectively. CO2 emissions per gallon appear quite favorable for ethanol. However, the results are less dramatic when CO2 emissions are compared per unit of energy produced.

Figure 2 CO2 per KWH

When measured in pounds of CO2 per kilowatt-hours (KWH) of energy, the results show ethanol producing 6% less CO2 than diesel or biodiesel and 5% less than gasoline. In the case of ethanol, the lower specific energy of the fuel negates the benefit of its lower CO2 emissions. Meaning more ethanol is consumed to travel the same distance as gasoline or diesel thereby limiting the benefit of its lower CO2 emissions.

The bottom line is ethanol does not ameliorate our dependence on foreign oil and while it demonstrates higher performance for racecars, it is still less efficient than gasoline diesel, and biodiesel, and diverts food production away from providing for people and livestock. The reality is there are special interest groups that obfuscate the facts about ethanol for their own benefit. The real solution to our imminent energy crisis is alternative energies including cellulosic ethanol, solar, hydrogen fuel cells, and wind.

After reviewing some of the details of Honda’s experimental solar-power hydrogen refueling station in Torrance, CA and its fuel cell vehicle several questions concerning efficiency and practicality come to mind. It most be noted that solar and hydrogen don’t emit harmful byproducts such as carbon dioxide or carbon monoxide so both technologies are important to our energy security. First let’s look at the efficiency of hydrogen and second the efficiency of generating hydrogen from solar.

As we learned from science class, hydrogen is the most abundant element in the universe. Hydrogen has approximately 3 times the energy per unit mass as gasoline and requires about 4 times the storage volume for a given amount of energy according to a Hydrogen Energy report from Stanford University. In further review of additional information on hydrogen we are also making some adjustments to our fuel-ranking table.

We are revising Table 1 that was used in our post of October 3, 2007 for data on the energy density for hydrogen from 2.5 kilowatt-hours (KWH) per gallon to 10.1 KWH/gal and is reflected in the revised Table 1 below. The discrepancy lies in measuring the weight of hydrogen in liquid volume. We are calculating the energy density of hydrogen using the high heat values of hydrogen of 61,000 British Thermal Units (BTUs) and a weight 0.57 pounds per gallon from the Stanford Hydrogen Report.

As a reference: 1 KWH = 3,600 kilojoules = 3,412 BTUs

Revised Table 1 Specific Energy, Energy Density & CO2

Hydrogen offers tremendous energy potential, but as we see from Table 1, hydrogen has a low energy density meaning it requires a large storage container to make it practical for use in a motor vehicle. Several car manufacturers including GM and Toyota have developed hydrogen vehicles. Hydrogen can be used in internal combustion engines replacing gasoline or in fuel cells to generate electric to power the vehicle. However, there are some limitations to the current technology that may limit the economic viability hydrogen powered vehicles in the near term. But there are no detrimental emissions with hydrogen as apposed to hydrocarbon fuels thus providing tremendous benefits as vehicle efficiency improves.

Honda’s solar-powered hydrogen fueling station takes nearly a week in sun to produce enough hydrogen to power Honda’s FCX concept hydrogen fuel cell vehicle. Honda employs a Proton Exchange Membrane Fuel Cell (PEMFC) that converts hydrogen to electric that in turn, powers the vehicle. The Honda FCX fuel cell vehicle has two fuel tanks that can be filled with up to 156.6 liters of hydrogen or about 43 gallons that offers 430km (267 miles) driving range. The hydrogen fuel cell vehicle provides a reasonable driving range, but with a fuel efficiency of 6.5 miles per gallon (MPG), suggests more research is needed.

BMW’s Hydrogen 7 can travel 125 miles on hydrogen and 300 on gasoline before refueling. In tests the BMW 745h liquid-hydrogen test vehicle has 75 kg tank has a Hydrogen Fuel Efficiency of 10 km/liter or about 25.2 MPG and cruising speed of 110 MPH. Not too bad for an internal combustion engine that is able to run on gasoline or hydrogen.

Figure 1 Specific Energy

Given the changes to hydrogen’s energy density we are also adjusting hydrogen density (Figure 2) to reflect liquid hydrogen and high-energy value as noted by Hydrogen Properties College of the Desert.

Revised Figure 2 Energy Density: KWH per Gallon

We still have more questions given hydrogen’s very high specific energy, (3 times that of gasoline) and low energy density (4 times the volume of gasoline). Hydrogen is more efficient then petroleum fuel, yet when used as a fuel cell in a vehicle Honda’s MPG of 6.5 MPG is quite low. The fuel efficiency of BMW’s Hydrogen 7 of 25.2 MPG is only at parity with gasoline.

The efficiency of using solar energy to generate hydrogen may not be the most efficient method. One report from Walt Pyle, Jim Healy, and Reynaldo Cortez Solar Hydrogen Production by Electrolysis indicated that a 1-kilowatt solar photovoltaic device could generate 1 cubic meter of hydrogen in 5.9 hours. Essentially, 5.9 KWHs from a 1KW solar cell produces 1 cubic meter of hydrogen. We know that a pound of hydrogen in liquid state equals approximately 61,000 BTUs (51,500 BTUs at low heat value) or 17.9 KWH.

Research at Caltech, suggests that photoelectrochemistry The Lewis Group may offer a more efficient means of generating hydrogen. We will continue to explore solar efficiency and hydrogen fuel cells to evaluate the economics of alternative energy.

The bottom line is that our dependence on foreign oil is the biggest threat to national security and without cultivation of alternative energies we continue to endure an untenable situation. Further research into solar and hydrogen fuel cells could significantly ameliorate our dependence on oil.

Despite efforts that have enabled the U.S. to limit its demand for oil, world oil demand is up significantly. Advances in technology such as solar energy and vehicle fuel cell could help the world reduce its dependence on oil.

Figure 1 Oil and Gold Prices

The U.S. Department of Energy (DOE) and the U.S. Environmental Protection Agency (EPA) today released the Fuel Economy Guide for 2008 model year vehicles Fuel Economy Leaders: 2008 Model Year Coming in first place is the Toyota Prius (hybrid-electric) with city/highway miles per gallon (MPG) of 48/45. With higher fuel costs more people are factoring in fuel efficiency into their purchase decision. However, it is the purchase of pickup trucks and SUV that account for most of the vehicle purchases in the U.S. and these vehicles are dramatically less fuel-efficient than hybrids and small four-cylinder automobiles.

Despite the trend towards larger vehicles, the U.S is not experiencing a rapid rise in oil demand. Yet oil prices continue to climb. While geopolitical risk may account for the bulk of the recent price increase, latest information from the U.S. Energy Information Administration (EIA) Total Petroleum Consumption shows increasing oil demand from China.

Figure 2 Oil Demand: U.S. and China

Figure 2 illustrates that while oil demand in the U.S. has grown only modestly since 2000, the growth in China’s oil demand is rising rapidly. The recent data from the EIA shows oil demand through Q2/07. The demand for oil in the U.S. is up 5% from 2000 while in China oil demand is up 59% over the same period.

Improving vehicle fuel efficiency may abate rapidly rising oil demand in the U.S., but more emphasis on diesel and hybrids could take us a lot further. For example, Toyota has been slow to introduce its diesel line of pickup trucks in the U.S. while it offers a broad line of more fuel-efficient vehicle outside the U.S. Toyota offers several cars and trucks in Europe with impressively high fuel efficiencies that are not available in the U.S. Infact, the Toyota Hilux two-wheel drive pickup truck offers a four-cylinder diesel engine with an MPG of 44.8 on the highway and 29.1 in the city.

We are also seeing progress on fuel cell vehicles that could ultimately ameliorate are demand for oil, if not eliminate it entirely, all with no carbon dioxide or other emissions. We see most major automakers developing hydrogen powered fuel cell vehicles. Honda for one has the right concept in employing solar energy to make hydrogen.

Honda’s experimental hydrogen refueling station in Torrance, CA increases the solar incre3ases the efficiency of hydrogen fuel by using solar energy to produce hydrogen. The hydrogen is then used to power Honda’s Honda’s FCX concept hydrogen fuel cell vehicle with the only emission being pure water vapor. These fuel cell vehicles may not be ready for prime time, they provide a clear reality to what is achievable.

The bottom line is that supply and demand dictate price and the availability of cheap oil is on the decline. Further research into solar and hydrogen fuel cells could significantly change our dependence on oil.

With the Solar Decathlon is taking place in Washington DC today promoting commercially available solar energy technology and oil prices pushing to an all time high of $84/barrel, where are we in terms of cost parity with hydrocarbon fuels. Advances in solar energy technology, lower production costs, and rapidly rising oil costs could bring solar energy into parity with hydrocarbon fuels within five years.

The cost of solar energy remains prohibitively high at about $0.45 per kilowatt-hour (KWH) for an installed system. (a kilowatt-hour equals a 100-watt light in operations for 10 hours and equals 3,412.14 British Thermal Units – BTU) As a reminder, there is significant variance in cost per KWH ($0.23-to-$0.68) because a solar energy system is dependent upon daily available sunlight, which varies from about two hours a day in Alaska to almost six hours in Arizona. Solar energy costs are based on data from solar photovoltaic (PV) supplies SunPower (SPWR) and Sharp Solar.

In comparison to hydrocarbon fuels, one gallon of gasoline has an energy value equal to approximately 125,000 BTUs and cost around $3.00/gallon. The energy value of a gallon of gasoline equates to 36.6 KWH, therefore its price is about $0.08 per KWH. So there is significant disparity between gasoline at $0.08/KWH and solar energy at $0.45.

Fortunately, there are a number of initiatives seeking to improve the economics of solar energy. When we measure the cost of solar energy in dollars per watt we find a complete solar energy systems cost around $8.90/watt. (If we amortize the $8.90/watt over a twenty year expected life of a solar energy system, it amounts to $0.45/KWH) To improve the economic value of solar energy we can lower production costs and/or improve solar efficiency in terms of raising the KWH of electric produced per solar panel.

From the Lewis Group. at Caltech, we learned about several technological approaches to improving solar energy efficiency. Among some of the leading solar technologies are multi-junction semiconductor cells and solar concentrators. In a multi-junction cell, individual cells are made of layers, where each layer captures part of the sunlight passing through the cell. One of the key limits to solar efficiency are the semiconductor band gaps where excess solar energy is lost to heat instead of being converted to electric. Solar concentrators amplify available sunlight and increase the watts per square meter per solar panel.

Last year the Department of Energy reported that solar energy achieved a new record in efficiency performance. The news release, New World Record Achieved in Solar Cell Technology. suggesting that solar concentrators and multi-junction PV cells could surpass the Shockley-Queisser single-junction solar efficiency limit of approximately 31% for single layer solar cell. The multi-junction, concentrator solar cell produced by Boeing-Spectrolab (a Boeing company BA) achieved a world-record conversion efficiency of 40.7% in lab experiments while commercial products operate at 26.5%-to-28.3% efficiency range.

The DOE believes breakthroughs in solar efficiency such as these may lead to systems with an installation cost of only $3 per watt, which translates into a cost of $0.15/KWH. In addition, solar PV cell suppliers are diligently working to reduce production costs. SunPower is targeting a 23% solar efficiency as a goal to reduce its solar energy system cost by 50% by 2012. Semiconductor solar cells benefit from economies of scale, which could reduce cost by 20% for each doubling of production. These solar initiatives should act to reduce solar energy costs.

Meanwhile, as energy costs rise with oil at $84/barrel, the cost of gasoline is expected to increase. If gasoline at the local filling station rises to $6.00/gallon, its cost in KWH jumps to $0.16/KWH. At that price gasoline would be above those achievable through solar energy advancements of $0.15/KWH.

Figure 1 Photovoltaic Device: Efficiency/Cost

With pricing on PV cells falling below $3.00/watt (or $0.15/ kilowatt-hour), solar energy will be close to parity with conventional hydrocarbons. If the cost of gasoline rises to $6.00 a gallon, it would cost $0.16/KWH while current cost of electric is about $0.11/KWH because of the low cost of coal. The bottom line is innovative research initiatives have the potential to deliver disruptive technologies that significantly changes the economics of delivering an energy solutions to all nations.

Further review:
Please see research at California Institute of Technology’s division of Chemical and Chemical Engineering at The Lewis Group.
Imperial College, Jenny Nelson’s Third generation Solar Cells.
DOE’s National Renewable Energy Lab (NREL) Third Generation Solar Photon Conversion (Exceeding the 32% Shockley(Exceeding the 32% Shockley—Queisser Limit)
Solar Energy Market Data Solarbuzz

The U.S. Department of Energy (DOE) is quite correct in suggesting that if every household in the U.S. substituted a 100-watt standard light bulb for a Compact Fluorescent Light bulb (CFL), it would eliminate an amount of carbon dioxide (CO2) equivalent to one million automobiles. However, it is the bigger picture that matters, – motor vehicles contribute the most to CO2 emissions. We must not forget that by focusing on CO2 emissions, they are admitting that CO2 is a real issue that potentially leads to global warming and climate change.

Let’s look at some facts about our carbon footprint. A 100-watt light in operation for 13.3 hours produces approximately one pound of CO2 when the electricity is generated by coal. Coal has significantly higher carbon emissions per kilowatt-hour (KWH) than oil or gas. Please see Carbon content of fossil fuels . Coal generates about half the electric power in the U.S. and produces roughly ¾ of a pound of CO2 for every KWH of electric. That means for every 1.3 KWH of electricity used (a 100-watt light used for 13.3 hours) we produce 1 pound of CO2. And remember it’s the oxygen in the air that contributes nearly 73% to the weight of CO2. This is why more CO2 is created than the actual weight of the fuel.

Using the same fuel emissions data, a motor vehicle with an average fuel efficiency of 22 miles per gallon (MPG), produces approximately 90 pounds of CO2 for every 100 miles driven. A gallon of gasoline produces nearly 20 pounds of CO2. That equates to one pound of CO2 for every mile driven by an SUV with a fuel efficiency of 19 MPG. (19.9 pounds/gallon times 1 mile divided by 19 MPG)

While it makes sense to address the issue of CO2 emissions, particularly as coal accounts for half of electric power generation and has higher CO2 emissions per KWH than oil, the real issue is an energy plan that givers us energy independence. Energy independence should equate to national security.

With the rapid growth in vehicle use around the world, it would be nice to know what are the most efficiency, economic, and least carbon emitting fuels. The number of motor vehicles on the road is increasing rapidly. The number of cars and trucks in China is up over 3,600 percent in the last thirty years. Data from the U.S. Department of Energy (DOE) and Ward’s Communications, Ward’s World Motor Vehicle Data provide an interesting view of the growth in motor vehicle use.

Figure 1 China Truck and Car Registration

While the U.S. still accounts for the largest motor vehicle market, the rest of the world is quickly accelerating towards more vehicles on the road. Figure 2 shows the number of vehicle registrations over the last thirty years for China, the U.S. and the rest of the world (ROW). Vehicle registration growth in the U.S. has been growing at a 2% per year rate from 1975 to 2005. The largest growth in vehicle registration is in China and India where growth in the last ten years is up 195% and 99%, respectively.

Figure 2 World Vehicle Registration

With an explosion in motor vehicle use, what fuel should we be using to better performance and reduce emissions? Let’s go back to two basic concepts of energy: Specific Energy and Energy Density. For a quick review, (Molecular Weight Calculator) the specific energy of a fuel relates the inherent energy of the fuel relative to its weight. Specific energy is often measured in kilo-joules per gram (kj/g). One kilo-joule equals one kilowatt-second meaning one kilowatt-hour (KWH) equals to 3,600 kilo-joules. Also one British Thermal Unit (BTU) equals 1,055.05585 joules. A reference to the specific energy and energy values of most fuels can be found at Hydrogen Properties

Figure 3 Specific Energy

By specific energy hydrogen is the clear leader. However, vehicles must inherently carry their fuel supply, so to determine which fuel is best for motor vehicles, energy density of the fuel is the next measurement. While vehicle fuel efficiency is dependent upon a number of factors such as engine type and performance, make and model of vehicle, road conditions and fuel, we are focusing on fuel energy.

Figure 4 Energy Density: KWH per Gallon

Figure 4 illustrates how fuels compare with respect to energy density, that is, energy relative the container size. We again are using KWH to measure energy value. Hydrogen, because it is so light, requires 15.9 times the container volume to provide the same energy as diesel. Biodiesel provides more power per gallon than Ethanol, which requires 1.6x, the container size for the same amount of energy as diesel. Biodiesel and diesel are relatively similar with respect to energy density. While both Ethanol and Biodiesel are both form of renewable energy, Biodiesel offers more bang per gallon. Before we are able invest more into hydrogen and solar energy to bring alternative energy into parity with conventional hydrocarbon fuels, diesel and biodiesel offer better energy efficiency among hydrocarbon fuels.

Table 1 Specific Energy, Energy Density & CO2

As a final assessment of hydrocarbon fuels, let’s compare carbon dioxide (CO2) emissions among our list of fuels. CO2 emission is a function of carbon concentration and combustion process of the fuel. Fuel energy research at the Department of Environmental Protection (EPA) and DOE indicate 99% to nearly 100% combustion of with fuels used in vehicles. That means almost all of the atoms in the fuel are converted to either heat or byproducts such as CO2.

Figure 5 illustrates how much CO2 is produced per gallon of fuel. Remember the molecular weight of CO2 is about 44 with oxygen contributor nearly 73% of the weight and is taken from our atmosphere during combustion. This is why more CO2 is created than the actual weight of the fuel. A second factor needs to be considered when evaluating CO2 emission and that is how much CO2 is produced per energy value. In comparing CO2 emissions per KWH of energy, Ethanol produces about 7% less CO2 than diesel or Biodiesel and 5% less than gasoline. Neither of these estimates considers the emissions from the processing to produce Ethanol or Bioiesel.

Figure 5 CO2 per Gallon

The bottom line is Ethanol and Biodiesel provide marginal relief to our energy crisis with biodiesel offering better efficiency and Ethanol marginally less CO2 missions. The only real solution to our imminent energy crisis is alternative energies such as solar, hydrogen fuel cells, and wind.

Oil prices remain at historically high levels and threaten our economy with higher home heating and transportation costs. With a lot of rhetoric over Peak Oil as well as claims that Tar Sands offer a viable substitute for oil, let’s examine a couple of facts to determine the feasibility and sustainability of supplementing our current demand for oil with tar sands.

According to Bureau of Land Management’s on line resource for Oil Shale and Tar Sands, tar sands are a mixture of clay, sand, water, and bitumen, which is liquid hydrocarbon oil like substance. Tar sands consist of about 10%-to-15% liquid hydrocarbon and an 80%-to-85% mixture of mineral water, clay, and sand, and 4%-to-6% water. It takes about two tons of tar sands, which are extracted, mainly through strip mining, and processed to produce one barrel of oil.

According to Alberta Energy, sand oil production was at 966,000 barrels per day (bbl/d) in 2005 and is expected to reach 3 million bbl/d by 2020 and possibly even 5 million bbl/d by 2030. Alberta’s sand oil reserves at 1,704 million barrels, but proven and extractable using current technology, the estimate is 175 billion barrels which is second to Saudi Arabia’s 260 billion according to CBS 60 Minutes

However, with productions level of Alberta’s sand oil at 3 or even 5 million barrels per day, it represents just 4%-to-6% of the world’s oil needs. The U.S. consumed an average of approximately 20.5 million bbl/d in 2006 as indicated by the Energy Information Administration.

If it takes two tons of tar sand to produce one barrel of oil, the ability to increase production to 3 million barrels per day would amount to mining of 2.1 billion tons of tar sand. Total coal mining in the U.S. for 2006 was 1.1 billion tons according to EIA Coal Data At 5 million barrels per day, equivalent to about 6% of the world oil production in 2006, would amount to 3.6 billion tons of tar sand. That would be significantly larger than the 1.3 billion tons total world production of Iron ore in 2005 Info Comm. That appears to be a lot of mining for a 6% increase of oil on the world market. The added tar sand oil would make a significant contribution to U.S. oil needs.

According to the Canadian Association of Petroleum Producers capital investment in Alberta’s oil sands amounted to $10.4 billion in 2005. That’s not a bad investment considering that even with production levels of 1 million barrels a day, revenue potential could be $29 billion a year with oil over $80 per barrel.

Figure 1 U.S. Oil Supply and Demand

Given the that tar sands only provide a fraction of our energy requirements and is burdened by carbon emission even during extraction, a commitment to solar energy fuel cells may offer a better return on investment. The bottom line is oil derived from tar sand is only a supplement to our energy demands, it’s non-renewable, adds to carbon emissions, requires extensive processing, and must be mined.

With rising energy prices and growing concern over global warming, will advances in solar and alternative energies enable the development of affordable and efficient energy solutions. Caltech research on the energy conversion process may offer some insight.

Energy conversion, ways of converting sunlight to electric and chemical energy, offers promising advancements to make solar and hydrogen energies more practical and affordable. On the forefront of energy conversion research, the framework of developing disruptive energy technologies, is The Lewis Group, that is part of the California Institute of Technology’s division of Chemical and Chemical Engineering. The Lewis Group is working in several research areas some geared towards to better understanding of energy capture, conversion of light into electrical and chemical energy, and energy storage. These research projects include photo-electrochemical, which focuses on the chemistry of semiconductors and materials, surface modification of semiconductors to improve electrical properties, and nanocrystalline titanium dioxide that could potentially lead to significantly lower cost for converting sunlight to electrical energy. The Lewis Group research projects are much more than improving photovoltaic devices; they are also exploring ways to convert sunlight into stored fuel energy.

While we are providing a brief and very oversimplified view of the solar energy research, it is important to understand the dynamics of energy conversion because the conversion process impacts the efficiency and the production cost of photovoltaic (PV) devices and fuels cells. The Lewis Group has an interesting PowerPoint presentation available for download providing an overview of energy from consequences of CO2 emissions to the latest in new technologies to improve alternative energies. Of particular interest are the historical efficiency trends for various materials used in crystalline and thin-film solar cells, energy conversion strategies of turning light to fuel and electric, and the cost/efficiency tradeoff in photovoltaic devices.

Cost/Efficiency Tradeoff
Photovoltaic devices are limited in their practical efficiencies governed by the thermodynamic limits and production costs that involve tradeoffs in materials, production processes, and PV device packaging. The Lewis Group provides a thorough illustration of the efficiency trends for various PV devices materials such as crystalline silicon used in semiconductors as well as the new approaches to thin film PV including amorphous silicon, cadmium telluride (CdTe), copper indium deselenide (CIS) and copper indium gallium deselenide materials (CIGS). These thin film material could offer substantial PV devices price reductions as a result of higher efficiency or lower production costs.

Figure 1 Cost/Efficiency Tradeoff

There is a tradeoff between improving the efficiency of a PV device, that is the amount of electric energy per solar panel, and the cost to produce the PV device. The average efficiency for a PV device is between 15%-to-16% and the average cost between $100-to-$350 a square meter. The cost per square meter and PV efficiency measured in watts per square meter can equate to a cost per watt, which ranges from $1.25/watt to $2.00/watt. SunPower (SPWR), offers the leading PV single junction device efficiency of 22% employing crystalline silicon and is expected to reach 500 megawatts (MW) production capacity by late 2009 from 330 MW in 2007. First Solar (FSLR) is ramping its thin film cadmium telluride (CdTe) solar technology by leveraging its low cost advantage with high volume production with its 75 MW in operations Ohio and 100 MW coming online in Germany. Startup Nanosolar is focusing on thin film solar PVs with a blend of copper indium gallium deselenide (CIGS) materials along with a manufacturing process much like printing, by placing the material blend upon metal foil. Evergreen Solar (ESLR) employs an integrated manufacturing process from wafers to cells and panels based on its proprietary String Ribbon Wafer technology with production levels at 118 MW in 2007.

There is presently a practical limit to solar efficiencies of approximately 30% and a thermodynamic limit of about 83%. The Shockley-Queisser limit at 30% for single junction solar cell efficiency is a function photon absorption in a material. “Detailed Balance Limit of Efficiency of p-n Junction Solar Cells” (W Shockley and HJ Queisser, Journal of Applied Physics, 1961) found that photons delivering excitation energy above a threshold (the band gap) for charge carrier electrons is lost to heating, meaning excess photon energy generates heat and not electric current. Photons with energy levels below the band gap pass through the material and photons above the threshold are absorbed. The absorbed photons transfer their energy to excite the electrons in the material and create pairs of negative electrons and positive charges that, because of their repulsion, travel to opposite ends thereby generating electric current.

According to the Lewis Group, other factors that limit PV cell efficiency include reflective loss of approximately10% for a material like silicon and a fill factor constraint that peaks at 83%. The fill factor restraint is attributable to the current-voltage characteristics of a PV cell that deals with matching the photocurrent density and voltage.

NREL (DOE lab) and Spectrolab (a Boeing company BA) using a multijunction semiconductor approach along with solar concentrators have achieved solar cell efficiencies of 40.7% in lab experiments while commercial products operate at 26.5%-to-28.3% efficiency range. Solar cell suppliers could reduce costs through production improvements or improve PV efficiencies without adding to costs. PV cell suppliers should benefit from economies of scale to reduce production costs while advances in technology improve PV efficiencies.

Research conducted by the Lewis Group at Caltech indicates that materials selected for PV devices have unique properties in their ability to absorb sunlight and generate electricity. In their analysis of semiconductor materials, the Lewis Group research found two parameters, determined by the physical properties of the material, that influence the PV’s efficiency. One is the thickness of the material, measured in microns, required to absorb enough sunlight to bring particular atoms in the material to an excited state, thereby freeing the electron to generate an electric current. The second parameter in the PV material is length of time the excited electrons last before recombining to generate heat instead of electric. Some materials such as silicon require material thickness of 100 microns while gallium arsenide (GaAs) only 1-to-3 microns.

Energy Conversion
Conversion of energy into electric or fuel is advancing through research in photoelectrochemical materials for solid and liquid fuels. Improvements in efficiencies for PV devices and fuel cells offer tremendous potential for transportation and home electric use.

Figure 2 Efficiency of Photovoltaic Devices

From figure 2, it seams quite apparent that PV efficiency has improved substantially since the 1950’s. Please see the Department of Energy (DOE) Basic Research Needs for Solar Energy Utilization for detailed analysis of solar energy. Further progress in PV and fuel cell technologies is predicated upon successful funding of further research. The bottom line is that only through innovative research will a truly disruptive technology be developed that has the ability of changing the economics to deliver an energy solutions to all nations.