Nonrenewable Energy Chapter 12 Tuesday, March 8 th, 2016

Concept Map We will be using these review notes to create a concept map for Nonrenewable energy. Main topics include: –Energy Use –Laws of Thermodynamics –Quality & Net Energy –Types: Description, Pros/Cons –“Nonrenewable” – What does that mean? What are our options/plans for the future?

What types of energy do we use? 1.Direct SOLAR ENERGY 2.Indirect SOLAR ENERGY 3.COMMERCIAL ENERGY

1. DIRECT SOLAR ENERGY Photovoltaic Cells Solar Thermal

2. INDIRECT SOLAR ENERGY Biofuels Wind turbines Hydroelectric dams

3. COMMERCIAL ENERGY From nonrenewable resources Extracting/burning nonrenewable resources (FOSSIL FUELS)

Energy Use: World & US

Energy Use WORLD 85% Nonrenewable Use of coal Use of oil Nuclear leveled off Developing countries depend on biomass (firewood, charcoal) for heating/cooking – can’t afford fossil fuels US 93% Nonrenewable World’s largest energy user 5% of world’s population uses 25% of world’s energy

Power – Rate work is done (how fast energy is transferred) – kW, J/S, watts – At any given time Energy – The ability to do work – kWh is the total amount of energy that has been delivered over a period of time – kWh, cal, J, BTU… Similar to speed vs. average speed

 Nonrenewable resources cannot be replaced  Fossil fuels are derived from biological matter (coal, oil, and natural gas)  Nuclear is derived from radioactive materials  Amount of energy use depends on availability and affordability  Patterns of use in US  Wood until 1875, than coal followed by natural gas and oil. Nuclear around 1950 and renewable in the 1970s

FOSSIL FUELS * Composed of partially decayed organism remains Nonrenewable Form too slowly to replenish NOT sustainable EX: Coal, Oil, Natural Gas

Formation of Fossil Fuels Formation of Coal - Over time, plants die, covered by water and sediment - Heat and pressure convert material into carbon rich ore (COAL) and sedimentary rock. Formation of Oil Death and buildup of microscopic aquatic organisms. Heat and Pressure convert material to hydrocarbons (OIL) without oxygen in sediments that prevent decay. Formation of Natural Gas Same as oil, just produced at higher temperatures than oil.

FOSSIL FUELS Developed countries consume 8x MORE energy than developing countries

What is Net Energy and why is it important? Net energy is the amount of high-quality energy available from an energy resource minus the amount of energy needed to make it available. Net Energy = Total amount of useful energy available Energy needed to make it available -

Basic Science: Net Energy is the only energy that really counts First law of thermodynamics: –It takes high-quality energy to get high- quality energy –Pumping oil from ground, refining it, transporting it Second law of thermodynamics –Some high-quality energy is wasted at every step

Net Energy Ratio Energy Produced : Energy Used to Produce it Net Energy Ratio, Net Energy Conventional Oil = HIGH net energy ratio, But decreasing

 To determine best use of energy, we look at energy efficiency ((output/input) * 100)  Gas used for transportation because a small volume goes a long way and it burns easily, but pollutes  Most fossil fuels around 35% efficient  Must know complete picture to choose best fuel and to calculate true efficiency  How much energy does it take to obtain the fuel

 Starts with sun, and the potential energy is converted into electricity  Ultimate goal is to spin a turbine (fluid). Usually done with steam (burn coal to get steam)  Spinning turbine spins a generator that creates electricity that gets sent through transmission lines  Capacity is the maximum potential output  Cogeneration is the use of fuel to generate electricity and heat  Can be 90% efficient vs. 35% for just electricity

Reducing Energy Waste Improves Net Energy Yields and Can Save Money 84% of all commercial energy used in the U.S. is wasted –43% after accounting for second law of thermodynamics Drive efficient cars, not gas guzzlers Make buildings energy efficient

 Petroleum is liquid fossil fuel  Oil and natural gas form from marine phytoplankton  Found where porous rocks are capped by nonporous rocks  Accumulate at bottom of ocean floor  Buried and heated until they became complex carbon molecules  Found in porous rocks covered by nonporous rocks  Makes up fuels, plastics, lubricants, tar, etc  Pros: lots of energy, helps economies, many uses, easy to transport (pipeline)  Cons: pollution (CO2, sulfur, heave metals), oil spills, nonrenewable, plastics, foreign

We Depend Heavily On Oil

 Refining crude oil:  Based on boiling points, components are removed at various layers in a giant distillation column.  The most volatile components with the lowest boiling points are removed at the top.

How long might conventional supplies of oil last? SHORT ANSWER = ??????? Rapid increase of use since 1950 Largest consumers in 2009 –United States, 23% –China, 8% –Japan, 6%

The United States Uses Much More Oil Than it Produces Produces 9% and Uses 23% 1.5% of World’s Proven Oil Reserves – most in Environmentally sensitive areas Import 52% of our oil for $ 200 billion

 Coal is mostly used for electricity  Coal is solid fossil fuels made from plant remains  Sediments piled up on plant remains and compressed them  Chemical reactions break down chemicals except carbon  Heat and pressure turned this into coal  Stages:  Begins as peat (compressed plant materials)  Lignite (water gets forced out, and becomes 40% carbon)  Bituminous coal (soft coal, 85% carbon)  Anthracite coal (95% carbon) – most available energy  Pros: plentiful, needs minimal refining, lots of energy, inexpensive  Cons: nonrenewable, destroy landscape, runoff, pollution (SO2 and CO2), heavy metal release, acid rain

Increasing moisture content Increasing heat and carbon content Peat (not a coal) Lignite (brown coal) Bituminous (soft coal) Anthracite (hard coal) Heat Pressure Partially decayed plant matter in swamps and bogs; low heat content Low heat content; low sulfur content; limited supplies in most areas Extensively used as a fuel because of its high heat content and large supplies; normally has a high sulfur content Highly desirable fuel because of its high heat content and low sulfur content; supplies are limited in most areas Stepped Art Fig , p. 382 Stages in Coal Formation

 Surface Mining Control and Reclamation Act (1977)  Requires filling (reclaiming) of surface mines after mining Expensive!  Reduces Acid Mine Drainage  Requires permits and inspections of active coal mining sights  Prohibits coal mining in sensitive areas

Solutions for “Cleaner Coal” Install Scrubbers (Desulfurization systems) Used to clean power plant exhaust Chemicals in scrubber react with pollution causing it to precipitate out EXPENSIVE, but EFFECTIVE

Solutions for “Cleaner Coal” Legislation to reduce emissions Clean Air Act Amendments -Cut emissions and require installation of scrubbers

 Natural gas (CH4) is found with petroleum  Pros: burns cleaner, transported through pipes, many uses, economical  Cons: it is a greenhouse gas itself, leak easily, explosive, nonrenewable

 Bitumen (tar, pitch, or oil sands)- a degraded type of petroleum that forms when a petroleum migrates close to the surface, where bacteria metabolize some of the light hydrocarbons and others evaporate.  To mine for these is very energy intensive  Less efficient  Liquid coal  Lots of coal available, but twice the pollution and more expensive

 Less that 40 years of oil likely remain  Slightly longer for natural gas  At least 200 years of coal

 Objective 1: Increase Energy Efficiency and Conservation  Objective 2: Secure Future Fossil Fuel Energy Supplies  Objective 3: Develop Alternative Energy Sources  Objective 4: Meet the First Three Objectives Without Further Damage to the Environment