Solar and Electricity Test

Passive solar heating

Captures sunlight with windows and converts to low-temperature hear for space heating (3 season room)

Face South

Advantages to solar heating

No cost to operate

No pollution

Eliminate/reduce heating

Disadvantages to solar heating

Added cost for design and building

Doesn’t work well during extreme weather

Solar power tower

Computer controlled mirrors that track the sun and focus sunlight on a central heat collection tower.

(Mojave desert in California)

Solar power tower advanatages

Cost will drop as tech improves

Solar power tower disadvantages

Costs 8x more to build

Where is the largest solar power tower?

Ivanpah, Mojave Desert

347,000 mirrors

173,500 heliostats

Operated by NRG

Solar thermal plant

Sunlight is collected and focused on oil-filled pipes

that run through the middle of curved solar collectors

Solar thermal plant advantages

Generate high temps

Cheaper than nuclear

Solar thermal plant disadvantages

Expensive to operate

Only good in dry desert locations

Solar cooker

Focuses and concentrates sunlight in a box typically covered in glass to trap infrared radiation waves to cook food in rural villages in developing countries.

Solar cooker advantages

No energy needed

Solar cooker disadvantages

2-4 hours to cook average meal

PV cells

An electronic device that converts sunlight into electricity using the photovoltaic effect

How much does it cost, the payback time, and the grants to install PV solar cells?

$20,000

Federal grant - $8,000

NYS grant - $4,500

$12,500 in total

6-8 years

What do PC solar cells do?

Produces power for home

Makes DC and uses invertor

Extra power sold back to utilities

Nighttime power comes from utilities

Pros to PV cells

100% renewable

Can be done on individual homes or commercial buildings

Does not need 100% sunshine to operate

Warranty for 25- 30 years of operation

Cons to PV cells

Expensive but cost is decreasing

Only produces power during day

Can be damaged by weather

Requires large surface area to be built

Hydroelectric power plant

Water spins the turbines in the “powerhouse”. Water is stored in a reservoir during low electricity production. Water is released, and flows are controlled as electricity demands peak.

Hydropower pros

High energy output

Low operating/maintenance costs

Low air pollution

2-10 times longer life than other

Most efficient way of making power

Hydropower cons

Creates floods

Destroys habitats

Uproots people

Decreases fish harvest

What is an example of tidal power?

Barrage de la Rance

1966

France

Tidal power pros

Tidal energy spins turbines

Long endurance

Tidal power cons

Few suitable sites

Expensive to build

3 examples of biomass

Wood

Ethanol

Sugar

Biomass pros

Potentially renewable resource

Less air pollutants released

Decrease in use of fossil fuels

Moderate-high net energy yield

Biomass cons

Removal of trees depletes soil nutrients

Soil erosion (turbidity)

Flooding

Loss of wildlife habitats

Large land areas needed

Heavy pesticide/fertilizer use

Reduces biodiversity and ecological integrity

Wave energy pros

Operates 24/7

Little impact on life

Wave energy cons

Expensive to build

Hard to maintain

Ocean current energy pros

Large force

Reliable

Ocean current energy cons

Expensive to build

Corrosion from salt water

Hard to maintain

Geothermal energy

Heat contained in underground rocks and fluid that can be tapped for energy.

Numbers about geothermal energy

22 countries use it

It supplies 1% of world energy

USA makes 44% of geothermal in Hawaii, Cali, Nevada, and Utah

Geothermal energy pros

Reliable

96% less CO₂ emitted

Fairly cheap to make

Geothermal energy cons

Scarcity of locations

Noisy

Oder (rotten eggs)

How many homes can one windmill power?

700

Wind power pros

100% renewable

Little maintenance

Dual use of farm land

1 windmill = 1 acre

Wind power cons

Large

Can’t be in residential areas

Not reliable

Cogeneration

Cogeneration or combined heat and power is the use of a heat engine or power station to generate electricity and useful heat at the same time

Solar-hydrogen

Water can be split into gaseous hydrogen and oxygen.