renewable energy - building blocks

8/2/2019 Renewable Energy - Building Blocks

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Renewable Energy Essentials

Building Blocks


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Energy Basics

What is renewable energy?

Difference between power and energy

Typical domestic service requirements Space and water heating

Lighting and appliances Matching renewables to these energy services -

which produce heat and which produceelectricity?

Key differences between renewables and fossilfuel systems

Renewables in the context of carbon allowances


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What is renewable energy?

Definition

Energy flows which are replenished at the same

rate as they are used (Sorenson, 1979)

Secure and inexhaustible Also low carbon dioxide emissions

All six technologies stemming from solar energy


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Forms of renewable energy

Direct

Photovoltaic

solar water heating ground source heat

pumps

Indirect

Biomass(photosynthesis)

Wind (thermal currents)

Hydro (hydrologicalcycle)


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Power and energy

Energy and power are NOT the same thing

Energy - is measured in Joules (J) (after James Joule)

Power - is measured in Watts (W) (after James Watt)


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Power or energy?

Energy is more often measured in kilowatt-hours(kWh) as this is the unit used to pay for energy.1 kWh = 3600 kJ

Power is measured in Watts (W) or kilowatts (kW) andis the rate of consuming (or generating) energy1 W = 1 Joule per second

For comparison, a 1-bar electric fire has a powerconsumption of 1kW (1000 J/s)


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Power or energy?

Energy consumption = power consumption x time

(e.g. If a 1-bar electric fire left on continuously for 1 day it would

consume 24 hours 0 x 1 kW = 24 kWh of energy)

Energy generation = power generation x time

(e.g. If a 5kW wind turbine generates equivalent to rated power for

30% of the year, it will generate 5 x 0.3 x 8760 = 13,140kWh per

year)

Power refers to either heat or electricity


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Heat or electricity

Type of outputType ofrenewableenergy Heat Electricity Heat and

Electricity

Photovoltaic Solar water heating

Micro-hydro Ground source heat pump

Biomass CHP

Wind Biomass heating


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Energy use in the home

Carbon Emissions of the UK Housing Stock in 2001 by End Use

Lights and appliances 24%

Domestic hot water 20%Cooking 3%

Space heating 53%


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Household energy consumption

2-bed terrace 2000 9,850

Size ofproperty

Annual energy demand (kWh)

DHW Space heating

3-bed semi 2500 13,500

4-bed detached 3000 20,750

Power (electricity for lighting and appliances)Typical annual household consumption about 4,000 kWh


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What are the key differences between the

renewable energy technologies to be coveredand conventional fossil fuel systems?

Intermittency Storage

Complexity

Auxiliary systems

Lower (or zero) running costs

Carbon neutral reduce CO2 emissions and

other pollutants Harness local resources so potential for

local income generation


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Carbon allowances

550ppmvconvergence at 2050

Future projections

450ppmvconvergence at 2030

Total Personal

10.40 5.20

9.60 4.80

8.20 4.10

6.80 3.405.30 2.70

3.90 2.00

tCO2 550 ppm (2050 tCO2 450 ppm (2030

Total Personal

1.40 5.20

8.90 4.50

6.00 3.00

3.00 1.502.60 1.30

2.10 1.10

Total Personal

10.70 5.40

10.40 5.20

10.80 5.40

11.70 5.9

BAUYear

2002

2005

2010

2020

2030

2040

2050

renewable energy - building blocks

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