energy alternatives ii: non-renewables & renewables

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Energy Alternatives II: Non-renewables & renewables

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Page 1: Energy Alternatives II: Non-renewables & renewables

Energy Alternatives II:Non-renewables & renewables

Page 2: Energy Alternatives II: Non-renewables & renewables

Non-renewables: fossil fuels

• There is no global shortage of fossil fuels– Petroleum: 50+ years left– Coal: hundreds of years– Natural gas: decades

• FF are easy to find, mine & consume

• FF prices are quite low• Distributional issues• Price issues• Environmental issues

Page 3: Energy Alternatives II: Non-renewables & renewables

There is still lots of oil around the world

Page 4: Energy Alternatives II: Non-renewables & renewables

The problem remains: who has it, who wants it, and how will it get from one to the other

Page 5: Energy Alternatives II: Non-renewables & renewables

1 trillion cu. meters gas = 6.29 billion bbl oil

There’s also quite a bit of natural gas: about one trillion barrels of oil equivalent

Page 6: Energy Alternatives II: Non-renewables & renewables

1 billion metric tons coal = 2.45-4.9 billion bbl oil

And a lot of coal: 2-4 trillion barrels of oil equivalent

Page 7: Energy Alternatives II: Non-renewables & renewables

In principle, fossil fuel supplies are not a serious problem

In practice, it appears that they are (or will be)

Page 8: Energy Alternatives II: Non-renewables & renewables

Nor can the political implications be ignored

• Even if oil is not really scarce, perception creates myths, and myths can lead to conflict

• Even if climate change proves not to be a problem, there’s still a lot of pollution from ff

• And cheap energy fosters growing demand, which has to be supplied somehow

• We’ll return to these points next week

Page 9: Energy Alternatives II: Non-renewables & renewables

What about energy alternatives?

• Hydroelectricity• Geothermal• Fuel cells• Ocean energy• Fusion• Biomass• Wind• Solar• Hydrogen

Global oil use = 500 trillion liters/year

Page 10: Energy Alternatives II: Non-renewables & renewables

And don’t forget how compact & convenient ff are

Page 11: Energy Alternatives II: Non-renewables & renewables

What should we look for in energy alternatives?

• Reduce vulnerability, increase flexibility• Be environmentally-friendly or “green”• Be cost-effective & efficient• Be sustainable over the long-term• Not introduce major lifestyle disruptions• Not generate intractable waste problems• Not solve one problem only to create others• Not introduce intractable social problems

Page 12: Energy Alternatives II: Non-renewables & renewables

Hydroelectricity is one very effective & wide-spread renewable energy source

Page 13: Energy Alternatives II: Non-renewables & renewables

Its total potential is limited and large dams are not without environmental & social impacts

Total global electrical production = 20,000 TWh/yr.

Page 14: Energy Alternatives II: Non-renewables & renewables

In theory, geothermal is widespread &

could provide heat & electricity

Energy in Iceland

Page 15: Energy Alternatives II: Non-renewables & renewables

In practice, again, accessible geothermal reservoirs are limited, and recent efforts to fracture bedrock to release geothermal heat appeared to cause earthquakes, leading to cancellation of projects in Switzerland & California

Page 16: Energy Alternatives II: Non-renewables & renewables

The oceans offer almost limitless energy potential

Wave energy power—note the very high energy potential in the North Atlantic, off the Irish coast: the Saudi Arabia of waves!

So far, various technologies have not panned out or proven economical—but that could change

Page 17: Energy Alternatives II: Non-renewables & renewables

It might also be possible to use ocean temperature differences to produce heat much like refrigerators

No commercial-scale systems yet…

Page 18: Energy Alternatives II: Non-renewables & renewables

Fuel cells can generate electricity directly, but require a fuel source to drive electricity production. A few small test plants appear to be in operation

Page 19: Energy Alternatives II: Non-renewables & renewables

But fusion is always 50

years in the future

And there’s always fusion

The fuel source is virtually unlimited

Page 20: Energy Alternatives II: Non-renewables & renewables

Fusion reactors will involve very complex designs, and they will be very expensive

Depending on fuel, they could also generate considerable amounts of radioactive materials

Page 21: Energy Alternatives II: Non-renewables & renewables

Biomass conversion involves chemical reduction into liquid fuels, which is already being done on a very large scale in the U.S. & Brazil

Depending on source, it might displace food production (as with corn ethanol).

Page 22: Energy Alternatives II: Non-renewables & renewables

Solar energy is plentiful but diffuse, and must be collected, concentrated & stored

Page 23: Energy Alternatives II: Non-renewables & renewables

It can be used to heat or boil water, the latter to generate steam

Page 24: Energy Alternatives II: Non-renewables & renewables

Built onto buildings, on as part of the structure, it can generate electricity

Page 25: Energy Alternatives II: Non-renewables & renewables

Global production of solar PV cells is growing, while cost is dropping

But solar is diurnal, at best, and some kind of storage system is required for times when it is not available

Page 26: Energy Alternatives II: Non-renewables & renewables

There is a lot of wind energy potential, especially out in the oceans

Page 27: Energy Alternatives II: Non-renewables & renewables

Wind is variable and diffuse and must be backed up by some other electrical source (could solar &

wind back up each other?)

Page 28: Energy Alternatives II: Non-renewables & renewables

Wind resources are widely available

Page 29: Energy Alternatives II: Non-renewables & renewables

Costs of wind are decreasing, capacity is growing, but so is the average size of turbines.

These tend to be quite noisy & to kill birds, and there is growing opposition to them

Page 30: Energy Alternatives II: Non-renewables & renewables

What about hydrogen? Solar in the desert could be used to make hydrogen, which could be piped to cities.

Page 31: Energy Alternatives II: Non-renewables & renewables

Mtoe

0

5,000

10,000

15,000

20,000

25,000

1990 2020 2050 2100

SolarHydroBiomassNuclearN. GasCoalOil

Technological progress projection

Page 32: Energy Alternatives II: Non-renewables & renewables

This is one optimistic electrical generation projection—note that it is only electricity; liquids not included