Replacing Fossil Fuels with Renewables - Part 1

Economic Growth! Energy independence! Climate Change! There are countless arguments for moving beyond fossil fuels, for world energy needs. Unfortunately, many hurdles must be overcome before we can feasibly count on other sources of energy to replace coal, oil and possibly natural gas, which all together provide the lion’s share of the world’s electricity generation and transportation fuels.

Even if there were no greenhouse effect, all of the fossil fuels we rely on will probably be depleted within a few hundred years. If humankind is going to have a future on this planet, at least a high-technology future, it is absolutely inevitable that we’ll have to find an alternate energy pathway.

Energy Landscape

Two profound questions loom over all other energy concerns: will there be enough affordable energy in the near future to sustain the world’s economies? And, if not, what are the long term solutions?

There are no simple answers, today’s global energy economy is faced with increasing energy demand, depleting resources, rising energy prices, limited availability and reinforcement of countermeasures to reduce pollution and the effects of global warming.

The answers depend on each region’s inventory of resources and energy needs as well as their political and cultural environment.

The 1973 and 2009 fuel share of the world’s total energy supply is shown in the following chart: 1973 data is represented by the green columns, 2009 data the blue columns.

At present, fossil fuels still dominate world primary energy supply. Oil leads both coal and natural gas. However, between 1972 and 2009, oil showed a drop in share relative to coal and natural gas. Of the three fossil fuels, natural gas showed the largest increase between the two target years.

By 2009, biofuels and waste-to-energy made up another 10% of total supplies, followed by nuclear and conventional hydropower such as dams. Renewable energy sources round out the roster, accounting for less than 2% of production – mostly as the result of investments in wind and solar.

These sources and their proportions will have to change eventually, since the planet’s known supplies of fossil fuels are limited. But during the next couple of decades, the nation’s energy menu is unlikely to be substantially different from today – assuming “business as usual” conditions.

The total world energy consumption by country is illustrated in this map: the darker the color, the higher the energy consumption. Following the map is a chart showing the actual and projected growth rates of energy consumption by OEDC and and Non-OEDC countries from 1990 to 2040.

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“The Organization for Economic Co-operation and Development countries (OEDC), which were the center of energy demand, was impacted by the economic crisis, lower population growth and changes in their economic industrial structure. Their energy consumption fell in line with the drop in the European Union and the stagnation in North America. The demand for energy shifted from the OEDC countries to China, India, Africa and the Mideast; where energy consumption continued to grow steadily; with China widening the gap with the United States.” Source ExxonMobil
One of the most potentially important trends in the energy field is how emerging economies’ development priorities are shaping energy markets. These emerging countries are expected to make up the bulk of growth in demand for energy in the coming decades, with countries outside OEDC accounting for 83% of the expected growth in energy demand between now and 2035.

As the global centers of expansion, these non-OEDC countries will increasingly influence how new energy markets evolve. Many of these countries have new notions of sustainable development – that are likely to bring about energy systems different from U.S. or European models of energy infrastructure and use.

On the consumption side, this chart shows 1973 and 2009 fuel shares of the world’s total consumption.  1973 data is represented by the green columns, 2009 data the blue columns.   Source: IEA 2011 Key World Energy Statistics

Following a similar trend with production, consumption is dominated by fossil fuels.  Biofuels and waste-to-energy collectively called biomass emerge as a viable energy resource in the world market. However, their share has remained steady over the target periods.

As renewable sources of energy, wind, solar, geothermal and wave-action make a negligible contribution to world energy consumption. But in all fairness, if not supplied, it will not get consumed.

Electricity can’t be pumped out of the ground like oil or captured from moving air like wind energy. So it is called a secondary source of energy. Meaning it is produced from primary energy resources which include the remaining fuels shown in the chart.

Experts predict a 35% increase in demand for electricity by 2030. In practical terms, that means an equivalent increase in demand for coal and gas, at least for the next decade.

Electricity generating plants now consume a sizeable portion world energy from all sources, including 70% of world’s coal and nearly 40% of its natural gas. There is no immediate way to alter that situation. In the near term, renewable resources are unlikely to substantially change the mix of world energy supply.

While nuclear generation is A zero-atmospheric-emissions alternative that already produces  around 15% of the world’s electricity, efforts to increase that capacity face large, though not insurmountable, hurdles: high capital investment costs and resistance from citizens groups that oppose the use and storage of radioactive material.

The trend in international energy prices for fossil fuels is another important factor driving fuel utilization.

This series of charts show the variation and volatility in global spot prices for oil, coal and natural gas from 1985 to 2011, source: BP Energy Outlook 2030. Each fuel is displayed on a separate chart. The colored lines are prices from different traders; for the most part the lines are similar in shape and value.

Historically, oil prices are unstable and rise and fall in response to world economics, stability, speculation and rumors. The peaks and valleys can be traced back to any one or a number of these factors.

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Global crude oil markets have seen an erratic upward spiral in prices for many years. Looking down the road, there are no indications that this upward price pressure will ease in the foreseeable future; forcing price increases throughout the supply chain.

Coal prices have also been on the increase since 2005 and recently are hitting all-time highs. The rising price reflects the boom in demand for energy resources in China and India, as well as supply problems related to Australia’s floods.

Much to the dismay of environmentalists, the use of coal has increased over the past few decades both in absolute terms and as a percentage of total primary energy supply.  It is expected that this surging need for energy in emerging economies will not ease, especially with China. The continued pressure on coal demand over the next five years will have strong implications for world coal prices.

The boom in production of natural gas trapped in shale formations, which has been unlocked by new technology, has driven U.S. gas prices to a 10-year low – about where they were in 1976, and various low points in the 90s. This has proved a huge blessing for big industrial users of natural gas.

The gap between U.S. and international gas prices has expanded to all-time highs, giving American industries a competitive advantage. Energy intensive industries in Europe and Asia are becoming increasingly aware of the huge edge gained by shale gas production.

The fact is industrial countries are almost fully adapted to fossil fuels. Coal and natural gas provide the majority of power generation; Nuclear power, biofuel, waste-to-energy, and hydro-electric power all made inroads to replace fossil fuels in the world economy.

Energy Flow

The following figure is a single page reference that depicts the flow of energy and resource utilization, measured in petajoules; across the energy system of 136 countries for 2007.   Source: Lawrence Livermore National Laboratory of the U.S. Department of Energy

The chart illustrates the connections between primary energy resources (fossil, nuclear, hydro and renewables), shown at the far left, and end-use sectors categorized into residential, commercial, industrial, and transportation.

Electricity and Heat (E&H) generation is listed midway between the primary sources of energy and the final demand centers. The reason for this is E&H’s role as a secondary source of energy; consuming primary energy sources and supplying energy to end-use sectors.

Also in the end-use sector is non-energy, located between the industrial and transportation categories on the right hand side of the chart. Non-energy is the conversion of primary energy sources to durable products such as derived fuels.

The grey boxes on the far right quantify “Rejected Energy” and “Energy Services”, where Rejected energy refers to energy that’s lost and not used, like energy released as waste heat from boilers, car engines or power turbines.  Energy Services refer to energy that is used to perform work.

The size of each box and the thickness of each line is a relative measure of the amount of energy delivered or received.

To better understand how the chart is used, we will follow the flow of energy into and out of electricity and heat generation, or E&H, as follows:

E&H has a total energy capacity of 190,000 petrajoules (PJ). Starting from top to bottom, the primary energy sources flowing into and consumed by E&H is:

• 630 PJ of wind,
• 30,000 PJ of nuclear energy,
• 11,000 Pj of Hydro,
• 21 PJ of solar,
• 1,900 PJ of geothermal energy,
• 43,000 PJ of natural gas,
• 92,000 PJ of coal,
• 2,900 PJ of biomass, and
• 13,000 PJ of petroleum.

The energy from each fuel source not consumed by E&H flows to other demand sectors.  For example, only 92,000 PJs or 70% of coal’s total capacity is consumed by E&H, the remaining energy is supplied to the industrial and Non-Energy sectors.

Almost immediately it becomes apparent that every fuel source is used to generate electricity; with coal and Natural gas comprising two-thirds (2/3) of E&H’s energy portfolio. Nuclear, hydro and biomass are low mid-tier suppliers. The remaining fuels; geothermal, wind and solar are all renewable resources that comprise only a small fraction of E&H’s energy supply.

Looking at the output side of E&H, the one aspect of the chart that is blatantly obvious is most of E&H’s energy output is rejected. That is 120,000 PJ or more than 60% of all energy produced by E&H is lost and wasted as heat. Quite remarkable!

Only, the remaining 75,000 PJ, or less than 40%, of all energy from E&H is supplied to several demand sectors as useful energy to provide work, which in turn rejects some of this supplied energy as wasted heat.

The Energy Flow diagram can be summarized accordingly:

• The big three fossil fuels; coal, petroleum and natural gas are the primary sources of energy consumed in the world.
• The major consumer of energy is electrical generation followed by transportation.
• Renewables account for a small fraction of the world’s energy portfolio.
• Oil remains king of transportation, and is essential in many industrial processes such as the manufacture of plastics and fertilizers.
• The transportation industry is the most inefficient sector, losing 75% of its energy supply as heat, as shown by the thick grey line on its output side.
• Electrical generation is the major consumer of fuels in the global economy and like transportation is extremely inefficient.
• Industry is the most balanced; uses an equal combination of most primary fuels – and is highly efficient, turning 80% of what it consumes into useful work.
• On a relative basis homes and business are equally efficient.

This suggests that sustainable practices aimed at improving the efficiency of the world energy mix should be targeted to vehicles and electricity generation.

If successful, this would have a tremendous impact on reducing energy usage throughout the economy, eliminate the need to build more power stations, and reduce consumption of petroleum by the transportation industry. The chart also suggests that investing in sustainable solutions to make residential homes and commercial building more energy efficient will have a minor impact on reducing world energy supplies. Though, this approach can save the owner money on their utility bill.

Continue on for part 2 …

By. Dr. Barry Stevens