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When Will Renewables Replace Fossil Fuels?

June 6, 2011


The transition from a fossil fuel-based to a renewable energy-based economy is rather complex. It must be understood in terms of market demands, fuel types, government legislation and initiatives as well as global, technological, socio-political and economic factors. For simplicity and relevancy, this discussion is limited to the U.S. economy only.

The energy markets considered in this discussion include four major sectors: electric power generation, transportation, industrial and residential/commercial.  For the most part, the type of fuels discussed include the big five; petroleum, natural gas, coal, nuclear power and renewables. Renewables embrace: conventional hydrothermal, geothermal, solar, wind, and biomass.

To make a fact-based rather than perception-based answer, this discussion develops a foundation comprising background information, industry-recognized data, trend analysis, and modeling. Use of anecdotal and unconfirmed information was kept to a minimum.

Historically, the paradigm shift towards “renewable energy” is a much older discussion than most realize. It has taken the U.S. some 30 years to become aware of the need and another 30 years to do something about it. Add to that an additional 10 to 30 years for a new technology to have a major commercial impact, the entire cycle time becomes 70 to 90 years from awareness to large scale deployment. Putting this in perspective, from the fist piloted power airplane flight in 1903, an America first walked on the moon some 66 years later. This extremely rapid advancement from a rudimentary technology to a revolutionary achievement is unparallel in the ascent of man.

Additionally, government initiatives put in place for renewable energy some 20 years ago. The Matsunaga Hydrogen Research, Development and Demonstration Act of 1990 directed the U.S. Department of Energy (DoE) to establish a Hydrogen Technical Advisory Panel (HTAP). The HTAP’s mandate was to facilitate the development of hydrogen as an energy carrier and to make recommendations on the implementation and the associated economic, technological and environmental impacts of hydrogen-based energy systems. Complementing this Act, the DoE established short-, mid- and long-term national objectives to replace conventional energy with hydrogen, an inexhaustible source of clean energy. The transition goals were:
• 0.5 quads per year by 2000
• 4 quads by 2010
• 10 quads by 2030.
[Note: A quad is a unit of energy equal to 1015 (a short-scale quadrillion) BTU, or 1.055 × 1018 joules.]

At that time, California enacted legislation requiring that 2% of new, light-duty vehicles offered for sale within the state be non-polluting, zero-emission vehicles (ZEV) by 1998 and 10% by 2003.  Battery- powered electric vehicles were frequently identified as the technology option that would meet this requirement. I could go on ad nauseam with other examples from the past.

Overall, the U.S. government with its highly volatile initiatives, which come and go, lacks the interest of the country, insight, courage and will to do so.
To form an estimate of where the U.S. will be in 20 years, an analysis of current data is essential. The most comprehensive and recognized data comes from the Energy Information Administration (EIA), an independent statistical agency of the DoE. The EIA was created by Congress in 1977 to support the government’s decision-making ability by providing policy-neutral data.

The EIA reports that the Electric Power and the Transportation sectors of the economy absorb about 67% of all fuels supplied in the U.S. (see figure 2). The other two sectors, Industrial and Residential / Commercial use about 33% of all fuels used in the U.S. These last two sectors play a minor role on energy demand in the overall economy. For this reason, this analysis will focus on the Electric Power and Transportation industries.

Seventy percent of all the fuel used  by the Electric Power industry are non-renewable “fossil” fuels, such as petroleum, coal, and natural gas which are found below the earth’s surface (see Table 1). Renewable fuels considered by the EIA include; conventional hydroelectric, geothermal, solar, wind, biomass and others such as natural gas. Note, natural gas pumped from the ground is considered a fossil fuel. Natural gas generated from renewable sources such as landfill gas and water/sewage treatment is considered renewable.  Currently, “renewable” natural gas is supplied erratically, and therefore, not supplied when needed. Reliability is one key factors that differentiates some renewable fuels from other more reliable sources of energy.

For 2004 and 2009, about 70% of all electrical power generated in the U.S. was sourced from fossil fuels. For the same period, only about 9% of all electrical power generation came from renewable fuels. The major type of renewable fuels is hydroelectric, which constituted about 98% of all other renewable fuels. The remaining 2% of renewable fuels includes geothermal, wind and solar. Over the five-year period from 2004 to 2009, there was a 6% decrease in the use of fossil fuel and an 18% increase in the usage of renewables. The trend toward increased utilization of renewable fuels for electrical generation is subtle but potentially real.

a"Other" includes non-biogenic municipal solid waste, batteries, chemicals, hydrogen, pitch, purchased steam, sulfur, tires and miscellaneous technologies.

Another piece of highly relevant information is the energy consumption as a function of source (type of fuel) and sector (see Table 2,, page 37). This somewhat complex-looking Chart 2 is relatively easily to understand. Each Supply Source and Demand Sector is listed in a bubble or rectangle, respectively.

On the Supply side (left), the number within each bubble is the relative percent any given Source was used by the overall economy, i.e., petroleum, natural gas, coal, renewable energy and nuclear power comprised  37%, 24%, 22% 8% and 7% of all fuels used in the U.S. Therefore, at 37% Petroleum was the predominant fuel used in the U.S.

On the Demand side (right), the number within each rectangle is the relative percent any given Sector demanded energy in the overall economy, i.e. electric power generation, transportation, industrial, and residential/commercial comprised 40%, 28%, 21% and 11% of the energy demand in the U.S. Therefore, at 40% Electric Power generation was the predominate user of energy in the U.S.

Looking at the chart, the five Supply Sources are shown with lines connecting various Demand Sectors. The small number on the line indicates the percent that particular fuel was supplied to any given Sector. Similarly, The four Demand Sectors are shown with lines connecting various Supply Sources. The small number on the line indicates the percent of fuel source used by any given Demand Sector.

For example, the chart shows that of all the petroleum used in the U.S. in 2008, 71%, 23% 5% and 1% went to the transportation, industrial, residential/commercial and electric power sectors. On the other hand, of all the fuel used by the transportation sector in 2008, 95%, 3% and 2% came from petroleum, renewable energy and natural gas, respectively.

In summary, the above data suggests that for renewable energy to have an impact on the economy, the following must occur (ranked from highest to lowest impact):
1. The transportation sector must reduce its usage of petroleum.
2. The electric power industry must reduce its usage of coal.
3. The industrial sector must reduce its usage of petroleum.

Other changes in supply and demand may reduce our reliance on fossil fuels, but in the long run will have a lower impact than any given above.

Finally, to  answer the question three models were formulated. The first two models, “Steady State” and “Accelerated,” (see Tables 3 and 4) consider:
• The demand for natural gas will increase over time due to domestically abundant supplies, reduced environmental impact and relatively good return on investments.
• The demand for nuclear energy will remain flat due to high capital cost, regulatory and environmental issues.
(Note, date used for 2010, was that given for 2009 from Table 1.)

The Steady State Model is based on a constant compounded 5-year rate of change of -6% and +18% for petroleum/coal and renewable fuels only. These rates were derived from the Changes given in Table 1.

The Accelerated Model is based on the Steady State rate factored with an additional 66% to arrive at a 5-year compounded rate of change of -9% and +27% for petroleum/coal and renewable fuels only. All other assumptions were similar to the Steady State model.

To cover all the risks and uncertainties, a third or Average Model was developed to derive a reasonable answer. The Average Model averages all data points from the Steady State and Accelerated models (see Table 5).

To the extent that our government legislates and incentivizes renewable fuels, the rate of adoption may retard or accelerate from conventional wisdom. In the near term, the political news  for increasing demand of renewable fuels is less than favorable. In a recent announcement, the Senate decided to abandon all efforts to pass a comprehensive climate change bill. This leaves utilities, vehicle owners, businesses and homeowners with no direction and no reason to adopt more expensive renewable energy. As long as fossil fuel prices remain low largely due to tangible and intangible government  subsidies, it is difficult to make a strong financial case in favor of renewable fuels.

As a counterpoint, whether one believes or disbelieves in climate change or global warming, the issue of reducing our reliance on foreign oil and fossil fuels is as much a domestic economic issue as it is an environmental one. The U.S. spends about $1.3 million per minute, $57 billion a month and more than $685 billion a year to feed its addiction of foreign oil. It seems the U.S. government is myopic to its economic and environmental impact.

In closing, it’s about us, humanity and our future. We must find the leadership, courage and conviction to get off petroleum in order to keep our dollars in the U.S. by using clean, abundant and domestically produced energy sources. Only by these actions can we ensure our children’s children will have any measure of hope for the future.

My predictions for how much renewables are expected to replace fossil fuel over the next 20 years are shown in the Average Model, Table 5.

3 Comments leave one →
  1. June 10, 2011 6:03 AM

    Dear sir, i am c.s.bhaskar from secunderabad, AP, India. I am doing research in linear method cascading marine hydro electrical generation and the application is ocean water .A man made underground river slantingly down is dug from below 20 m deep ocean bed. There is 20 meters of ocean water as a stable head and under the ocean bed a 250 meters diameter and 100 meters deep well is dug, this well is also slantingly in arrangement. Now a slantingly sloppily down man made underground river having 150 meters diameter is dug from the very bottom of the well. This underground river is 40 kilometers long and 150 meters in diameter having man made gradient for the ocean water to run down the slope by the law of gravity. The power generation stations are arranged in cascading model. From the wells bottom 96000cubic meters running water per second runs down the 150 meters diameter underground river and fills the very first p1 reservoir completely. There by p1 reservoir will get completely full .P1 reservoir will be 2 kilometers long and the inlet of the reservoir is 150 meters in diameter and the outlet is 40 meters in diameter and the shape of the reservoir is just like a Missile. Water running out of the first reservoir (i.e.p1),96000 cubic meters per second will impinge the p1 generator-turbine and will generate green electricity and the p1 tail release will flow down into p2 reservoir and when the p2 reservoir is getting nearly full p2 reservoir outlet valve is opened and p2 turbine is impinged and in this method or manner all reservoirs arranged in cascading method will generate green electricity. There will be 20 individual reservoirs on the 40 kilometers long slantingly down man made underground river. Each individual reservoir will be having 150 meters inlet and 40 meters outlet. Each reservoir is having a individual Head and each reservoir is having a independent power generation unit at the end of the outlet. Each generator-turbine is 1000 megawatts and will get impinged with 96000 cubic meters ocean water every second having a independent head. For p1 reservoir the head is 20 meters ocean water + 100 meters slantingly down well + 150 meters underground river = 270 meters head and for p2 to p20 all 19 individual reservoirs constructed on the underground river will have 150 meters head because each reservoir is having 150 meters diameter inlet and 40 meters outlet and the power house is outside the 40 meters reservoir outlet.The turbine is in the path of flowing water,as soon as the reservoir oulet valve releases water the released water will impinge the turbine and flows out of the tail release the turbine rotates 24 x 7 all 365 days. All reservoirs are arranged like train compartments one after another. The outlet of the final reservoir will be at minus 400 meters below the main sea level and the tail release of the final turbine .i.e p20 will fall as a free water fall 15 meters down and this falling water is collected into the tail pond. The tail pond will get 96000 cubic meters ocean water every second and the tail pond will be 3 kilometers long having 20 meters depth and 150 meters wide. Water is pumped out by 2000 individual pump turbines. Each individual pump turbine will be 330 megawatts and will consume at least 240 megawatts of electricity and will pump out at least 50 cubic meters ocean water from minus 415 meters to above the main sea level so that the pumped out water will be sent back into the sea. Electricity can be generated from this running water too.
    In this process of green electrical generation the very first reservoir i.e p1 power generation is always for sale 24×7 and p2 to p20 all 19 individual reservoirs power generated power is for pump consumption.
    p1 reservoir will generate=10 gravity x150(m)head x 96000 cubic meters water per second x .60 efficiency= 86400000 KWH electricity generated per every one hour and in 24 hours the total generation will be 2073600000 kwh of green electricity for Sale.
    Generation cost is free because no cost of raw materials and no transportation.
    p2 reservoir will generate ,p= 10 x 40 meters head x 96000 cubic meters ocean water per second x .60 efficiency = 23040000 kwh electricity generated every hour from p2 reservoir x 19 individual reservoirs =437760000 KWH electricity per hour generation is consumed by 2000 individual pump turbines of 330 MW capacity each.
    The turbine is a Revolving Garden Gate model and will rotate by the reservoir pressure head.
    The Water pressure is transferred from 150 meters diameter reservoir inlet into 40 meters reservoir outlet and will flow into each turbine.
    thanking you
    with regards

  2. June 10, 2011 6:37 AM

    dear sir, we have to use 1.3 cubic billion kilometers of water in the oceans and this is the free raw material avialable on hand and there is no transportation required .we have to understand the cascading marine hydro electrical generaion technology for green power generation so that replacing fossil fuels is very easy and simple.The generation cost depends upon the raw material avialbility and transportation.
    sun will not shine 24 x 7 and wind will not blow evenly all the year. Only water can solve the problem for the replacing of fossil fuel perminently.


  1. By how much should we expect renewables to replace fossil fuels … | Alternative Energy Sources

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