OrkustofnunThe National Energy Authority

Prof. Dr. Gudni A JóhannessonDirector General

GEORG 25. Nov 2016

Role and Opportunities of Geothermal in Smart Energy Systems

1

Originally by Cullen & Allwood 2010

Global Primary Energy Use 2006

Definition of Exergy and Energy Quality

Heat reservoir

Mechanical work - ExergyHeat flow

Anergy

Environment

Quality of energy at T1

(Max exergy output)/energy

Exergy destroying processes

Electricity or fuels converted directly to heat

Mixing of water at different temperatures

Friction losses in fluid flow

Quality of energy• Quality of energy is the proportion of the

stored energy that can be used to generate work.

T0

Tr Qr

Work

Exergy X for a heat source depending on temperature

T0

Tr Qr m cHitastig varmageymis HlutfalloC K hágildisorku

500 773,15 0,43400 673,15 0,38300 573,15 0,33250 523,15 0,29200 473,15 0,25150 423,15 0,20100 373,15 0,15

80 353,15 0,1260 333,15 0,1040 313,15 0,0720 293,15 0,03

0 273,15

Viðmiðunarhitastig 273,15

W

Temperature Proportion exergy

Ref temperature

Electricity and fossil fuelsQuality factor 0,9 – 1,0

How Smart is Smart

• What is our perspective– The electricity producer – maximum revenues– The consumer – adequate service for a

minimum cost– Global climate change – minimum emissions

• Smart Stupid grids• Smart energy systems • Good energy quality management EQM

Energy Quality ManagementCommunity Level

Global EQM Potential

Total Primary energy use

475 TWhHeating 233 TWH

Saving potential by Energy Quality Management

150 TWh?

Total coal burning127 TWh

2006 values

The

Lind

al D

iagr

am

http://www.therockymountaingoat.com/2014/02/valemount-may-get-geothermal-workshop/

Geothermal Heat 2014

28.1 PJ in total

The Deep Drilling Project

>500 OC250 OC

Heat pump – highest theoretical COP

-5 0 5 10 15 20 25 300.00

2.00

4.00

6.00

8.00

10.00

12.00

14.00

16.00

Nothitastig 35 CNothitastig 55 C

0TTT

r

r

Source temperature OC

Heat pumps – measured COP

Fig. 1: Values of COP for brine/water heat pumps (as used typically in geothermal heat pump systems), measured in the Heat Pump Test Centre

Toess (extract from http://www.wpz.ch/)

The Price for Exergy• Reykjavik Energy – marginal cost

– Electricity including distribution• Energy price 13,79 kr/kWh• Exergy price 13,79 kr/kWh

– Hot water• Price 131,45 kr/m3 DT=(80-40) K • 46,4 kWst Reservoir quality at 80 C = 0,12• Exergy price = 2,83 kr/kWh/0,12 = 23,6 kr/kWh

• Heat pump alternative – equalized marginal cost• Relative COP = 0,58 x COPtheoretical

The Role of District Heating and Cooling

H. Lund et al. / Energy 68 (2014) 1e11

Supplied energy for district heating in Sweden, TWh

Oil

Biofuels, waste, peat

Heatpumps

Waste heat

Natural gas

Coal

Electricity

Increased market penetration• Integration into the total energy system• Increased penetration of district heating

and cooling networks• New generation of networks - prosumers• Industries• Biocultures• Absorptive and adsorptive cooling• Improved public acceptance• Deposition of gasses with reinjection

Future concepts?

• The HC-radiator

80OC

40OC

Heating

Cooling

No mechanical heating or cooling

Ambient outside air

Future Concept - Villa NOPOLI?

• Village with no powerlines• District heating system with mixture of

water and ethanol• Ethanol is evaporated and condensed on

house level for small electricity generation, cooking and afternoon toddy.

• Combined with local generation with wind or solar. (TESLA Powerwall?)

Thank you