Solar Unit

More vocab from Nova – Saved by the Sun Greenhouse gas – Gases that can absorb and emit infrared radiation.infrared radiation By their percentage contribution to the greenhouse effect on Earth the four major gases are – water vapor, 36–70% water vapor – carbon dioxide, 9–26% * key one to be concerned about carbon dioxide – methane, 4–9% methane – ozone, 3–7% ozone This process (absorbing and emitting infrared radiation(is the fundamental cause of the greenhouse effect.greenhouse effect

Carbon footprint - A carbon footprint has historically been defined as "the total set of greenhouse gas (GHG) emissions caused by an organization, event, product or person. greenhouse gas Renewable energy- Renewable energy is energy which comes from natural resources such as sunlight, wind, rain, tides, wavepower, and geothermal heat, which are renewable (naturally replenished).energynatural resources sunlightwindraintides geothermal heatrenewable

Carbon Dioxide Carbon Dioxide is: – a greenhouse gas (the one believed to be the most responsible for global warming). – Produced from animals breathing. – Produced from burning fossil fuels. – Produced from using energy (electricity) in our homes (which mostly comes from coal – produces CO2 or nuclear power) – Reduced by plants and using less energy

Non-renewable energy source – energy such as gasoline and natural gas which take millions of years to build up.

MORE SUN FACTS Emits energy in different sized waves (RADIATION). –Light (visible) –Heat (infrared - invisible) –Radio waves and X-rays (invisible)

Heat Transfer Heat Transfer: Conduction, Convection, Radiation Radiation – the sun’s energy being sent out in waves (visible and invisible) Convection – the up and down of liquids and gases caused by heat transfer (hot air rises). Conduction – heat being transferred by contact.

When is your shadow the longest? (sunrise and sunset) When is your shadow the shortest? (noon)

Why do dark colors get warmer faster? Dark colors do not exactly absorb more heat, but they do convert a higher percentage of light into heat. If you notice when heading out in the sun with a dark colored shirt it gets hot, where a lighter colored shirt would not get nearly as hot.the sun This is due to the amount of light being absorbed by the color. The lighter the color the smaller the range of visible light being absorbed and converted into heat.

White objects reflect all visible light, where black objects absorb all visible light. While color is a factor of light absorption, it is not the only factor. You will find that some dark objects remain cooler in direct sunlight then other lighter objects. This is due to the fact that there are other factors at play, maybe one material is a poorer insulator; possibly there is a shine to darker object, leading more light to be reflected as a result. If the material is the same, you will find that darker colors become hotter.play

Solar water heater lab: – A good solar water heater will be black in color. – A good solar water heater will have a lid.

2 main forms of solar powers are – – Heat – Light

Surface area - Surface area is the area of a given surface. Roughly speaking, it is the "amount" of a surface. Would a increase in surface area increase or decrease the heat? (increase)

Questions for back of surface area lab. 1. How was water heated by solar energy in the past? 2. What was the Day and Night system, and what was it used for? 3. How do solar water heaters work today?

The greenhouse effect is a process by which heat (thermal radiation) from earth is absorbed by atmospheric greenhouse gases, and is re-radiated in all directions.greenhouse gases Since part of this re-radiation is back towards the earth it results in a higher temperature.

Nuclear power Sustainable energy is the sustainable provision of energy that meets the needs of the present without compromising the ability of future generations to meet their needs.sustainable energy Nuclear power- Conventional fission power is sometimes referred to as sustainable, but this is controversial politically due to concerns about peak uranium, radioactive waste disposal, and the risks of a severe accident.fission powerpeak uranium radioactive waste disposal