1. Solar Energy – Its Huge!
Solar is the only renewable energy source that is ubiquitous enough to serve as a foundation of a global energy economy in nearly all the locations where energy is required.
The energy in sunlight striking the earth for 40 minutes = global energy consumption for 1 year.
There is far more solar energy received by a small part of public lands in the desert Southwest than the total energy utilized by the United States.

2. Methods of Harnessing Solar Energy
Passive: requires building design that captures solar energy heat and light when needed, and excludes it when excessive (usually by seasons). Many elements of passive solar design are cost effective without government subsidies.
Active: harnessing solar energy to store it or convert it for other applications. Some types:
Thermal: hot water for cooking, heating, or purification, industrial heat for melting, or electricity generation through steam turbines
Photovoltaic: direct electricity generation utilizing panels
Concentrating solar applications use mirrors or lenses to focus sunlight – and can be thermal or photovoltaic.

3. What does it cost to make solar electricity?
Its free!
Technology to capture it is still sold expensively, but is experiencing rapid declines in cost.
Global PV capacity growth 2005: 1.7 GW, GW (64% annualized) see graph
Grid-tied system installations are experiencing rapid growth. These systems sell back to grid when home or business demand is less than the electricity being generated.
In the sunny Southwest US, PV systems built and financed on new homes generate electricity for cents per kw-hr. (CA grid prices are cents per kw-hr.) math? 4kw solar system $18,000, financed 20 yrs, pmts $114 monthly, produces ~8000kw-hrs annually, worth $120 monthly if retail electricity is 15₵
Grid parity is thus being reached in sunny areas that have high electricity prices.
*including external costs of coal, such as health and climate change

4. The geography of solar PV market penetration – 3 drivers
1. Local retail price of electricity:
since solar PV is distributed/decentralized, it may someday compete with coal and other centrally generated sources, because it has no distribution costs.
b. since solar peaks in the day near peak demand times for electricity, it doesn’t have to compete with low cost baseload electricity that is available at night, but rather expensively-priced peak load retail power.
2. Local solar resources
3. Local cost of solar systems, including any gov’t incentive programs
Sunny places with currently high electricity prices are poised to be early areas of large market penetration.
In Japan, a country of modest solar energy resources, solar PV has become cost competitive with retail electricity. This happened because 1) Japan subsidized solar purchases to achieve mass production by many companies, and 2) Retail electricity is expensive, approximately 20 cents per kilowatt-hr. Subsidized mass production drove costs down to where they are today –
Cloudy Germany has a similar program to Japan’s, and led the world in installations in

5. What are some things that solar electricity can provide power for?
anything we currently use electricity for
plug-in cars, making it possible to replace petroleum for personal transportation, at least
What about the intermittency problem? See the Scientific American article for solutions using proven technology (The Grand Solar Plan, January 2008)
Also – plug-in car batteries may soon be part of a “smart grid” that can store electricity when needed. Some think hydrogen may be the ultimate energy storage/carrier, someday.