lecture 2 eea- sap, chennai

8/12/2019 Lecture 2 EEA- SAP, Chennai

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School of Architecture and Planning, Anna University Campus, Chennai

AD9022 ENERGY EFFICIENT ARCHITECTURE

RENEWABLE SOURCESOF ENERGY


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The world has reached peak conventional oil and gas, meaning oil and gas

companies are digging deeper and deeper into unconventional sources, with

disastrous environmental and social consequences.

Minimizing climate change impacts will require substantial cuts in global

emissions - as quickly as possible.

Coal is still relatively readily available, but catastrophic in terms of climate

changing emissions. The world can no longer afford to hang on to its old energy

paradigm, and its dangerous dependence on fossil fuels.

The pressure on the earths nonrenewable resources can be alleviated by

judicious use of earths renewable resources.



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The use of renewable energy in buildings has increased significantly recently due

to a number of other factors:

1.Increased fuel costs.

2.Reduced costs of renewable energy.

3.Increased interest in reducing building carbon footprints.



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A large variety of renewable energy systems, including the following:

Solar thermal panels

Photovoltaic panels

Wind turbines (large and small scale)

Bio gas and Biomass.

Tidal power.



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Which renewable

option is best for

my building?

Depends on the

size of thebuilding, energy

use, building

location, and

operational time.

And most

importantly

payback period.



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Before considering the use of renewable energy, one should examine how

buildings energy demand can be reduced through clever and often innovative

design techniques.

This includes passive building design techniques.(many of which add little or

no additional cost to buildings and are therefore of particularly high value toclients) review heating and electrical supply options.(including the use of

renewable energy)

This provides clients with the options available and assists in selecting the most

appropriate energy source for their development.

Actively encourage clients to procure low energy buildings and to include

renewable systems as a part of a detailed and integrated low energy strategy.



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Policies and programs promoting energy efficiency & renewable energyIntegration in Buildings in India.

The government through Ministry of New and Renewable Energy (MNRE) has

incentives the use of renewable energy technologies (RETs) in buildings through

Subsidies and other fiscal incentives such as tax holidays, accelerated

depreciation rates etc.

MNRE has started a solar cities program to promote the use of solar energy.

Energy Conservation Building Codes (ECBC) have also been developed to

propagate the practice of designing energy efficient buildings.

Though these codes are voluntary till now, their implementation has provided

a strong base for further energy efficiency measures in future.



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Solar thermal panels

Solar hot water systems gather energy from solar radiation and turn it into heat

that is then distributed in the form of hot air or water to where it is to be used or

stored until needed.

An active solar water heater consists of a solar collector(s), a hot water storage

tank(s), and a pump.



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In addition, a heat exchanger and expansion tank are required in freezing winterclimates and an electrical generation device is needed if regular AC grid-

connected power is not available.

Piping, insulation, valves and fittings are considered installation materials and

are normally available at hardware stores and plumbing centres.



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A solar collector consists of a translucent cover, an absorption plate and a heat

transfer system, involving hot water pipes or hot air.

A good liquid solar collector should have a minimum life expectancy of 2030

years.

Most of the collectors built since about 1980 are manufactured with materials

that should give a 3050 year lifespan with a small amount of periodic

maintenance.

Good liquid collectors typically have copper water ways (piping and

tubing), a tempered glass cover and an insulated metal enclosure.



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Although a little of the radiation falling on the translucent cover will be re-

reflected away, most will pass through and be absorbed by the absorption plate

and heat the water contained in it.



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WHY USE A SOLAR HOT WATER SYSTEM?

All Eco buildings should use solar energy to heat their water if possible.

This is because solar hot water systems (SHWS) are not only easy to build or buyand install but, above all, they use the free, clean energy of the sun.

HOW GREEN IS A SHWS?

The domestic sector is responsible for around 30 per cent of the carbonemissions of developed countries, mainly owing to the CO2 emitted as a by-

product of power generation and fossil fuel burning. Of this 30 per cent, 25 per

cent goes to heating water for use from the taps and to provide pre-heating for

space heating systems.



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PHOTOVOLTAICS

Photovoltaic cells convert sunlight directly into electrical

energy.

The electricity they produce is DC (direct current) and caneither be:

used directly as DC power;

converted to AC (alternating current) power; orstored for later use.



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The basic element of a photovoltaic system is the solar cellthat is made of a semiconductor material, typically silicon.

There are no moving parts in a solar cell, its operation is

environmentally benign and, if the device is correctly

encapsulated against the environment, there is nothing that

will wear out.



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Because sunlight is universally available, photovoltaicdevices have many additional benefits that make them not

only usable, but of great value us. They are the future and by

2020, when the conventional oil supplies begin to really dry

up, they will be everywhere.



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CROSS-SECTION OF A TYPICAL PV SOLAR SECTION



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WHAT IS A PV SYSTEM?

PV cells are typically grouped together in a module for ease of

use.

A PV system consists of one or more PV modules, which convert

sunlight directly into electricity, and a range of other system

components that may include an AC/DC inverter, back-up

source of energy, battery to store the electricity until it is needed,

battery charger, control centre, mounting structures andmiscellaneous wires and fuses.



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WHATS GREEN ABOUT PV?

The electricity produced by every square metre of PV can

effectively displace emissions of more than two tonnes of CO2 to

the atmosphere over its lifetime.

Counters impacts of buildings that are responsible for generating

over 50 per cent of all emissions of greenhouse gases globally.



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ADVANTAGES OF PHOTOVOLTAICS AS A DOMESTICSOURCE OF ENERGY

They are low maintenance.

Once installed they will simply require their surfaces cleaning, especially industy environments.

They can provide power in locations remote from the grid.

PVs are a transportable technology and can be moved betweenbuildings.

They can provide power during blackouts.



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WIND TURBINES

Wind energy has been used for pumping water and milling

grain for hundreds of years.

More recently, wind energy has also been used for electricitygeneration.

Developing countries can take advantage of wind power on a

small scale, both for irrigation (wind pumps) and forgeneration of electricity (wind generators).



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WIND TURBINES



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WIND TURBINES

Small wind turbine systems, with a capacity ranging from 50

W to 10 kW and rotor diameter ranging from about 0.5 m to 7

m, are primarily used in battery charging.

The batteries can then be used for energy supply for houses,

hospitals, farms, telecommunication, navigation, etc. Wind

energy systems can also operate in parallel with diesel sets

or solar PV systems.



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WIND TURBINES



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COST, SAVINGS AND EARNINGS

Maintenance checks are necessary every few years, and will generally cost

around Rs.7000 to Rs. 14000 per year depending on turbine size.

A well-maintained turbine should last more than 20 years, but you may needto replace the inverter at some stage during this time, at a cost of ,Rs. 70,000

to Rs. 1,40,000 for a large system.

Savings:

Building-mounted turbines tend to produce less electricity per kW than pole-

mounted ones.

A well-sited 6kW turbine can generate around 10,000kWh per year equivalent

to around 5.2 tonnes of carbon dioxide a year generating income and savings.



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BIOMASS

Biomass is a renewable energy

resource derived from the

carbonaceous waste of various

human and natural activities.

It is derived from numerous sources,

including the by-products from the

timber industry, agricultural crops,raw material from the forest, major

parts of household waste and wood.



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BIOMASS

Biomass does not add carbon dioxide to the atmosphere as it

absorbs the same amount of carbon in growing as it releases

when consumed as a fuel.

Its advantage is that it can be used to generate electricity with

the same equipment or power plants that are now burning

fossil fuels.

Biomass is an important source of energy and the most

important fuel worldwide after coal, oil and natural gas.



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BIOMASS

Biomass fuels used in India account for about one third of the

total fuel used in the country, being the most important fuel used

in over 90% of the rural households and about 15% of the urban

households.

Advantages of biomass energy as an alternative energy source,

as it is renewable and free from net CO2 (carbon dioxide)

emissions, and is abundantly available on earth in the form of

agricultural residue, city garbage, cattle dung, firewood, etc.

Bio-energy, in the form of biogas,



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Geothermal energyis thermal energy generated and stored inthe Earth.

Thermal energy is the energy that determines the temperature of

matter.

The Geothermal energy of the Earth's crust originates from the

original formation of the planet (20%) and from radioactive

decay of minerals (80%)..



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70% comes from the decay of radioactive nuclei with longhalf lives that are embedded within the Earth

Some energy is from residual heat left over from Earths

formation.

The rest of the energy comes from meteorite impacts.



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space heating

air conditioning

industrial

processes drying

Greenhouses

Aquaculture

hot water

resorts and pools melting snow



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Direct Sources function

by sending water down a

well to be heated by the

Earths warmth.

Then a heat pump is

used to take the heat

from the underground

water to the substance

that heats the house.

Then after the water it is

cooled is injected back

into the Earth.



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lecture 2 eea- sap, chennai

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