Return for investment

For each of the 6 alternatives to oil find out and write down how much energy do you get back for the energy that is put into creating/ harnessing or storing the energy?

1. Human/animal corpse/organs/waste - 
It is said that treating the corpse/organs/waste of humans or animals can produce a fairly large amount of gas and this can be converted into energy. With the daily wastes, it can produce 1.5 million cubic feet of gas and it can fill 1250 tanker trucks. 

2. Wind power - 
A modern wind turbine has a maximum capacity of around 2000 kilowatts or  2 megawatts and it can generate enough energy and electricity for the average annual need for 1000 houses. Each house needs about 4700 kilowatts of electricity consumption. The wind turbines could produce more energy if it functions in full capacity, but it only operates 75% ~ 90% of the time. 

3. Solar power - 
If the solar paints that are 100 million square meters of a steel building are used to consvere energy for a year, it will produce 4500 gigawatts of electricity through the solar cells and this is equivalent to the production of energy of 50 wind farms. The cost of a solar panel that is 3Kw costs 6500 pounds. 

4. Coffee grounds - 
16 billion pounds of coffee is produced each year and with the amount of coffee grounds it produces, 340 gallons of biodiesel can be produced. It is said that starbucks wastes 210 million pounds of coffee grounds annually and this can produce 3 million gallons of biodiesel and 90000 tons of fuel pellets. 

5. Cows - 
Methane gas from cows can provide the drivers in a single country with a daily amount of 138,000 cubic feet of energy to run a car. Researches by Argentinian scientists have revealed that a single cow that  weighs 550 kg lets out 800 to 1000 litres of methane each day. Also, cow wastes produce 250 to 300 kilowatts of electricity daily which is enough to power 300 to 350 houses. A herd of cattle emits an average of 275 litres of pure methane and this can easily keep a refrigerator running for 24 hours. 

6.Hydropower - 
Hydropower is generated from falling, flowing or running water. With the pressure that water creates, it is converted to electrical energy. Dams are made to create such mechanical energy to electricity. The average power that a turbine creates is about 97 megawatt and a dam produces 2969640 kilowatt hours.