Let's start with energy conversion as I mentioned earlier energy appears in Nature in several forms. 1
We human make energy work for us by converting it from oneform to another form. 2
Let's consider fossil fuel. How fossil fuel are converted into other forms of energy. 3
I will show that in the following simple diagram by burning fossil fuel roughly of 90 percent 4
of the chemical energy is converted into heat using heat engine. 5
The thermal energy can be converted into mechanical energy 6
heat engine have a conversion efficiency of 60 percent. 7
The far majority of the current cars and trucks are based on this principle. mechanical energy can be 8
converted into electricity using electric generator which has efficiency of 90 percent this show that 9
in all process steps, making efficiency out of fossil fuel at least 50 percent of initial available 10
chemical energy is lost in the various conversion steps chemical energy can be directly converted into 11
electricity using something. 12
called fuel cell. the most common fuel used in fuel cell technology is hydrogen chemical conversion efficiency 13
is 60%. A regenerative fuel cell operates in the reverse mode and converts electrical energy into chemical energy 14
electrical energy into chemical energy such as an operation is called electrolytes 15
and the device operated in such a mode is called electrolyzer. 16
hydrogen electrolyzers of 50-80% have been reported. 17
Another route of making electricity is based on an alternative 'fuel' , nuclear energy. 18
Nuclear energy is the energy generated in nuclear fission reactions and generates heat as well. 19
This can be converted in electricity using the just introduced heat engines and electric generators. 20
Next, we will look at alternative energy conversions, which are not based on 21
fuels. 22
hydroelectricity is one example. 23
This potential energy of rainwater falling in mountain area or elevated is converted into mechanical 24
energy using dense using so-called tidal pools. 25
The potential energy stored in tidal can also be converted to mechanical energy the kinetic energy of 26
wind can be converted into mechanical energy using windmills. 27
Finally solar energy can be converted into electricity as well. 28
If solar light is directly converted into electricity using a devices based on semiconductor material 29
we call it photovoltaics. 30
Photo means light. 31
voltaic means electricity. 32
Typically the efficiency of most commercial modules are the range between 15 to 20 percent. solar light 33
can also be converted into heat. 34
This is what we call it solar thermal energy 35
example are heating of water flowing through a block observable material that is heated in sunlight. 36
This heat can be converted into electricity again. 37
Using the heat engine as the conversion efficiency of heat engine strongly depends on temperature and 38
concentrated solar power system are used to generate electricity so solar heating using so-called high 39
temperature collectors. 40
Next to generating heat and electricity solar energy can be converted into chemical energy as well. 41
Next to generating heat electricity solar energy can be converted into chemical energy as well. 42
This is what we refer to as a solar fuel. this is possible by using photovoltaics and regenerative 43
fuel cell. 44
But solar light can be also directly converted to fuel using photo electrochemical devices. 45
This means we can convert solar energy into electricity, heat and chemical energy 46
Renewable energy sources. renewable energy sources are the energy sources that are replenished by nature. 47
Process at a rate of comparable or faster than its rate of consumption by Humans 48
hydro wind solar energy. 49
All our renewable energy sources fossil fuel and nuclear energy are not renewable energy as their fuel 50
are consumed faster than they are generated in nature from all energy sources. 51
Based on chemical , thermal, nuclear, hydro, wind, solar, geothermal roughly one-third is being used to 52
generate electricity 53
electricity is a form of electrical energy that can be easily and cheaply transported with relatively small 54
losses. 55
through an electric grid we might not realize it anymore but electricity has made today's modern society 56
possible. 57
It's as simple of modern life and progress. 58
Electricity has been practically used for more than a hundred years now. 59
Electricity provide us the energy to cook food, to wash and to do laundry illuminate houses and street 60
watch TV, air conditioning and heat work on computer , surfing the Internet. 61
Access to electricity determines the living standards of humans. 62
We must realize that at around one point two billion out of there 7 billion people worldwide still don't 63
have access to electricity grid electricity worldwide is mainly generated from oil, coal, gas, nuclear 64
or hydro power. 65
Here we see the relative contribution of these resources to global electricity generation 2007 66
65 percent of electricity is coming from fossil fuel. 67
as shown. where coalis dominant contributor. 68
Unfortunately coal produce roughly 2 times more carbon dioxide being generated unit of energy in reference 69
to gas. nuclear power is responsible for 60 percent off the wall its electricity generation and the 70
hydro power and hydro power was 90 percent by far the largest contributor among the renewable energy 71
sources in their conversion from chemical and nuclear power to electricity. 2/3 of the energy is 72
lost. 73
1/3 end up form electricity means 40 percent of electrical energy is used in the residential purpose 74
and 47 percent is used in industry and 13 percent of energy is lost in transmission as you can see 75
in 2007 transport didn't play a significant role in electricity consumption. 76
However it expected that transport related electricity consumption will increase in the coming decade 77
as well. 78
In 2007, 22 hundred tera watt hour of electricity was generated world wide if we consider 79
0.5 gigawatt nuclear power plan. 80
It's means we need about 5000 nuclear power plants at around the world. 81
If our electricity needs the will it be fully covered by nuclear power realize that sources for electricity 82
generation might differ from country to country for example In the Netherlands, electricity generation 83
Heavily depends on the local gas resource and in Brazil hydro-electricity is the most important resource. 84
in the last 100 years 85
in the last 100 years that humankind's energy infrastructure heavily relies on fossil fuel. 86
We are quickly using that solar energy of millions and millions of years of cover into chemical energy 87
by photo-process and the stored in the form of gas, coal and oil. 88
How did we do that before the Industrial Revolution. 89
The main source of electrical energy back then was wood and biomass which is secondary forms of solar 90
energy the energy source was replenished in same characteristic time as the energy being consumed in 91
the pre-industrial era. 92
Humankind was basically living on secondary form of solar energy. 93
We are not claiming that since energy consumption was fully sustainable way of living. 94
We have to take in mind that due to increasing population density was already playing a role as the 95
end of first millennium. 96
In Europe the sun has been energy source for all process. 97
on the surface of this planet. 98
Wind is a result of temperature difference in the atmosphere introduced by solar radiation. waves are 99
generated by wind, cloud and rains are initially formed by evaporation of water due to sunlight because 100
the sun is the only real energy source we have. 101
We need to move back again to an era in which we start to utilize the sun to satisfy our energy needs is 102
in the next block, in next section we will introduce you to that technology which is called solar 103
energy specially PVor photovoltaic energy. 104
See you in the next block.