Sustainable Energy Technologies
MSE0290
3. Solar
Eduard Latõšov
Contents
Nature of solar radiation
Resources
Utilisation
Technologies
Planning
Summary
Nature of solar radiation
Nature of solar radiation
The Sun
The sun is a star, a hot ball of glowing
gases at the heart of our solar system.
Source: http://www.slate.com/blogs/bad_astronomy/2014/01/30/lunar_transit_sdo_sees_the_moon_block_the_sun.html
Nature of solar radiation
The Sun. Some facts.
1. The Sun is the Solar System
The mass of the Sun accounts for 99.8% of the mass of the Solar System. And most of that final
0.2% comes from Jupiter. So the mass of the Earth is a fraction of a fraction of the mass of the
Solar System.
2. The Sun is mostly hydrogen and helium
74% of its mass comes from hydrogen with 24% helium.
The remaining 2% is includes trace amounts of iron, nickel, oxygen, and all the other elements we
have in the Solar System. In other words, the Solar System is mostly made of hydrogen.
4. The Sun is huge, but tiny
With a diameter of 109 times the size the Earth, the Sun makes a really big sphere. You could fit 1.3
million Earths inside the Sun. Or you could flatten out 11,990 Earths to cover the surface of the Sun.
That’s big, but there are some much bigger stars out there. For example, the biggest star that we
know of would almost reach Saturn if it were placed inside the Solar System.
In the Sun's interior, a
thermonuclear fusion
reaction
converts the hydrogen into
helium releasing huge
amounts of energy.
Nature of solar radiation
Distribution
Solar radiation refers to the electromagnetic
radiation that reaches the Earth from the Sun.
Source: http://www.physicalgeography.net/fundamentals/7f.html
Nature of solar radiation.
Distribution
Resources
Resources
Global
The global solar flux (in kWh/m2/y) at the
Earth’s surface over the year
Resources
Europe
The average energy received in Europe is about 1 200 kWh/m2 per year.
Resources
Examples
Resources
Examples
Utilisation
Utilisation
Cumulative PV capacity grew at 49%/yr on average since 2003
Utilisation
Utilisation
Utilisation
The sun could be the world’s largest source of electricity by 2050, ahead of
fossil fuels, wind, hydro and nuclear, according to a pair of reports issued
today by the International Energy Agency (IEA).
The two IEA technology roadmaps show how solar photovoltaic (PV) systems
could generate up to 16% of the world’s electricity by 2050 while solar thermal
electricity (STE) from concentrating solar power (CSP) plants could provide an
additional 11%.
Combined, these solar technologies could prevent the emission of more than 6
billion tonnes of carbon dioxide per year by 2050 – that is more than all
current energy-related CO2 emissions from the United States or almost all of
the direct emissions from the transport sector worldwide today.
Cumulative technology contributions to
power sector emission reductions in ETP
2014 hi-Ren Scenario, relative to 6DS, up
to 2050
Utilisation
Technologies
Technologies
Solar collector
heat
Photovoltaic cell
electricity
Others (mainly steam/electricity production).
electricity
Technologies
Solar collectors
Types
flat plate solar collector
evacuated tube solar collector
Technologies
Solar collectors
flat plate solar collector
Flat-plate collectors, developed by Hottel and
Whillier in the 1950s, are the most common type.
Technologies
Solar collectors
evacuated tube solar collector
Technologies
Solar collectors
comparison
Technologies
Solar collectors
comparison
Technologies
Photovoltaic cell
Photovoltaics is the direct conversion of light
into electricity at the atomic level.
SOME
FACTS
Some materials exhibit a property known as the
photoelectric effect that causes them to
absorb photons of light and release
electrons
The photoelectric effect was first noted by a
French physicist, Edmund Bequerel, in 1839,
who found that certain materials would produce
small amounts of electric current when exposed
to light. In 1905, Albert Einstein described the
nature of light and the photoelectric effect on
which photovoltaic technology is based, for
which he later won a Nobel prize in physics.
Technologies
Photovoltaic cell
Sunlight is composed of miniscule
particles called photons, which
radiate from the sun. As these hit
the silicon atoms of the solar cell,
they transfer their energy to loose
electrons, knocking them clean off
the atoms.
Creating this imbalance is made possible by the internal organisation of silicon. Silicon
atoms are arranged together in a tightly bound structure. By squeezing small quantities
of other elements into this structure, two different types of silicon are created: n-type,
which has spare electrons, and p-type, which is missing electrons, leaving ‘holes’ in their
place.
When these two materials are placed side by side inside a solar cell, the n-type silicon’s
spare electrons jump over to fill the gaps in the p-type silicon. This means that the n-type
silicon becomes positively charged, and the p-type silicon is negatively charged, creating
an electric field across the cell. Because silicon is a semi-conductor, it can act like an
insulator, maintaining this imbalance.
Technologies
PV System
Technologies
PV System
Tracked and Static
Technologies
PV System
Tracked VS Static
EXAMPLE: CASE SPECIFIC VALUES
Technologies
Others. CSP
CORE IDEA:
CONCENTRATE SOLAR ENERGY TO GET
HIGH TEMPERATURE TO GENERATE STEAM
Concentrated solar power (also called concentrating solar
power, concentrated solar thermal, and CSP) system
Technologies
Others. CSP
Parabolic. Pipe. 1/2
Technologies
Others. CSP
Parabolic. Pipe. 2/2
PS10 solar power
plant in Andalucía,
Spain
Technologies
Others. CSP
CSP is being widely commercialized and
the CSP market has seen about 740 MW of
generating capacity added between 2007
and the end of 2010. More than half of this
(about 478 MW) was installed during 2010,
bringing the global total to 1095 MW.
Spain added 400 MW in 2010, taking the
global lead with a total of 632 MW, while
the US ended the year with 509 MW after
adding 78 MW, including two fossil–CSP
hybrid plants.
Technologies
Others. CSP
Planning
Planning
Capital costs
Source: IEA
Planning
Capital costs
Source: IEA
Planning
Technical definitions
The output per watt (W) installed (sometimes termed “watt-peak”, or Wp) does not
depend on nominal efficiency, which determines the required receptive area per watt.
The nominal efficiency relates to the power generated under so-called “standard
test conditions” (STC) – module temperature of 25°C, vertical irradiance of 1 000
W/m2, air mass of 1.5 (distance travelled through the atmosphere 50% greater than
when the sun is exactly overhead) and a specific irradiance spectrum. For example,
modules of 1 m2 would generate a maximum power of 150 W with 15% efficiency, and
200 W with 20% efficiency under the STC.
The actual output depends on the solar resource, the orientation of the modules and
the “performance ratio” (PR) of the system, which takes into account all efficiency
losses resulting from actual module temperature, module mismatch, varying irradiance
conditions, dirt, line resistance and conversion losses in the inverter.
Well-designed PV plants achieve average PR
of 80% to 90% throughout the year.
Planning
LCOE
Levelised cost of electricity (LCOE)
Source: IEA
Planning
LCOE
Summary
Disadvantages
CONS
1. Expensive
Debate! Nowadays, the best solar panels can in many situations be cheaper than buying electricity
from the utility. This wouldn`t have been possible without incentives.
2. Intermittent
Solar energy is an intermittent energy source. Access to sunlight is limited at certain times (e.g.
morning and night). Predicting overcast days can be difficult. This is why solar power is not our first
choice when it comes to meeting the base load energy demand. However, solar power has fewer
problems than wind power when it comes to intermittence.
3. Energy Storage is Expensive
Energy storage systems such as batteries will help smoothen out demand and load, making solar
power more stable, but these technologies are also expensive.
4. Associated with Pollution
While solar power certainly is less polluting than fossil fuels, some problems do exist. Some
manufacturing processes are associated with greenhouse gas emissions. Nitrogen trifluroide and
sulfur hexafluoride has been traced back to the production of solar panels. These are some of the
most potent greenhouse gases and have many thousand times the impact on global warming
compared to carbon dioxide. Transportation and installation of solar power systems can also
indirectly cause pollution. There’s nothing that’s completely risk-free in the energy world, but solar
power compares very favorably with all other technologies.
5. Exotic Materials
Certain solar cells require materials that are expensive and rare in nature. This is especially true for
thin-film solar cells that are based on either cadmium telluride (CdTe) or copper indium gallium
selenide (CIGS).
Summary
PROS
Advantages
1. Renewable
Solar energy is a renewable energy source. This means that we cannot run out of solar energy, as
opposed to non-renewable energy sources (e.g. fossil fuels, coal and nuclear).
We will have access to solar energy for as long as the sun is alive – another 6.5 billion years
according to NASA
2. Abundant
The potential of solar energy is beyond imagination. The surface of the earth receives 120,000
terawatts of solar radiation (sunlight) – 20,000 times more power than what is needed to supply the
entire world.
3. Sustainable
An abundant and renewable energy source is also sustainable. Sustainable energy sources meet
the needs of the present without compromising the ability of future generations to meet their
needs.
4. Environmentally Friendly
Harnessing solar energy does generally not cause pollution. However, there are emissions
associated with the manufacturing, transportation and installation of solar power systems – almost
nothing compared to most conventional energy sources. It is clear that solar energy reduces our
dependence on non-renewable energy sources. This is an important step in fighting the climate
crisis.
5. Reduces Electricity Costs
With the introduction of net metering and feed-in tariff (FIT) schemes, homeowners can now “sell”
excess electricity, or receive bill credits, during times when they produce more electricity than what
they actually consume.
Other keywords: SILENT, DISTRIBUTED, MANY APPLICATIONS, LOW MAINTENANCE
Any questions?