1. Nonrenewable Review & Renewable Introduction
Monday, January 9th, 2016

2. Energy Use: World & US
We get most of our energy by burning carbon-containing fossil fuels. Note that oil is the most widely use form of commercial energy and that about 79% of the energy used in the world (85% of the energy used the United States) comes from burning nonrenewable fossil fuels.

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

4. 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

5. Patterns of Energy Use in the US

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

7. 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.

8. 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.
Total amount of useful energy available -
Energy needed to make it available
Net Energy =
More formally known as EROEI

9. 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
Before oil is useful to use, it must be found, pumped, refined, & delivered. Takes energy (high quality) to do this.
2nd law – some of high quality energy wasted at each step.
Think of net energy like business net profit – total money taken in - expenses

10. Conventional Oil = HIGH net energy ratio,
Energy Produced : Energy Used to Produce it
Net Energy Ratio , Net Energy
Conventional Oil = HIGH net energy ratio,
But decreasing
It takes energy to pump oil from underground or undersea
Ratio less than 1 – energy is lost
If it takes 9 units of energy to grow 10 units of corn, ratio is approx 1:1. Ratio increases net energy increases

11. Electricity generation
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

13. 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

14. How can we use less energy?
Energy conservation- finding ways to use less energy. For example, lowering your thermostat during the winter or driving fewer miles.
Energy efficiency- getting the same result from using a smaller amount of energy.

16. Benefits of Conservation and Efficiency
Many energy companies have an extra backup source of energy available to meet the peak demand, the greatest quantity of energy used at any one time.
Variable price structure- utility customers can pay less to use energy when demand is lowest and more during peak demand.

17. Sustainable Design: Improving the efficiency of the buildings we live and work in. What is renewable energy? Renewable energy can be rapidly regenerated, and some can never be depleted, no matter how much of them we use.