Indirect Solar Energy

• Hydroelectric

• Wind

• Biomass

Unit 14 – Indirect Solar - Slide 1

Hydroelectric

Unit 14 – Indirect Solar - Slide 2

Power depends on flow rate

(m3/sec) and “head” (m)

High volume? Big head?

Unit 14 – Indirect Solar - Slide 3

How much from hydro?

Unit 14 – Indirect Solar - Slide 4

Issues with hydroelectric

• Is “dispatchable”

Unit 14 – Indirect Solar - Slide 5

• Limited number of places possible.

• Can displace large number of people

• Changes flow – silt buildup?

• Drought can decrease power just when

you need it.

Wind

Unit 12 – Energy from the earth - Slide 6

• Power depends on wind velocity and

size of turbine

• Average land based power ~ 2 MW

• Goes like vmax3

Wind Potential

Unit 14 – Indirect Solar - Slide 7

Issues with Wind

Unit 12 – Energy from the earth - Slide 8

• Can be built in small pieces in short

time scales

• Little effect on the land

• Not dispatchable

• Wind doesn’t blow all the time

• Wind is not where the people are

Cape Wind Project

Unit 14 – Indirect Solar - Slide 9

April 2015 - contracts with the

state’s two largest utilities were

terminated in January after Cape

Wind missed its December 31

financing deadline.

May 2014 – Federal judge dismisses

law suit against NSTAR power

purchase agreement

130 Siemens 3.6-megawatt

offshore wind turbines with

a capacity of 468

megawatts.

Off-Shore Wind (Others)

Unit 14 – Indirect Solar - Slide 10

England 7.9 GW(7MW turbines)

Denmark 1.3 GW(8.2 MW turbines)

China 4.6 GW

Germany 6.4 GW

Unit 12 – Energy from the earth - Slide 11

What is the power from an

average coal-fired power plant?

A) around 2 kilowatts (KW)

B) around 2 megawatts (MW)

C) around 2 gigawatts (GW)

D) around 2 terawatts (TW)

Unit 12 – Energy from the earth - Slide 12

What is the power from an

average wind turbine?

A) around 2 kilowatts (KW)

B) around 2 megawatts (MW)

C) around 2 gigawatts (GW)

D) around 2 terawatts (TW)

Unit 12 – Energy from the earth - Slide 13

What is the power from an

average wind turbine?

A) around 2 kilowatts (KW)

B) around 2 megawatts (MW)

C) around 2 gigawatts (GW)

D) around 2 terawatts (TW)

Biomass

Unit 12 – Energy from the earth - Slide 14

• Recycle carbon?

(1) Burn material (2) Distill

Issues with Biomass

Unit 12 – Energy from the earth - Slide 15

• Just cycle carbon in closed loop

• At the moment, lots of land involved

• Sugar okay, corn not so much

• Diverts crop land away from food (for

animals)

Cellulosic Ethanol

Unit 12 – Energy from the earth - Slide 16

• Uses cellulosic material (e.g. corn

waste, switch grass)

• Holy Grail of biofuels

• Miscanthus

• Transportation

cost (local)

• Regularity of

supply

How much comes from renewables?

Unit 13 – Solar Energy- Slide 17

Biomass

Unit 13 – Solar Energy- Slide 18

Solar?

Unit 13 – Solar Energy- Slide 19