Modular Solar Electri

(MSEP) System

Vahab Hassan

National Renewable 

Laboratory

June 18, 2000

Presented at the third an

nual Parabolic Trough Technology Workshop on June 18, 20

NREL/PR-550-40035
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Purpose and Objecti

• Discuss development and deploy

Modular Solar Electric Power (M

systems

• Feasibility of application of exis

power cycles to solar trough tech

• Identification of next action item
Modular Solar Electric 

(MSEP) Systems

• Concept Description

– MSEP combines field proven tech

ORC power unit and the CSP trou

– ORC power units have been succe

for resource temperatures up to 40
Modular Solar Electric 

(MSEP) Systems, con

• Concept description cont’d.

– CSP troughs have been deployed a

provide heat resources up to 735 

o

F

– Combination of these technologies 

great opportunities for modular ele
MSEP’s Unique Aspec

Advantages

• Links proven technologies such 

power cycle with trough solar te

• Makes trough technology availab

higher value distributed and remmarkets
MSEP’s Unique Aspec

Advantages

• Allows lower operating temperat

oF - 580 

oF):

– Means that lower-cost non-evacua

tubes may be used

– Efficient cost effective thermal sto– Smaller solar field
MSEP’s Unique Aspec

Advantages

• Reduces water utilization (ORC • Standalone and automated opera

minimal operator involvement
MSEP’s Past Experie

• Coolidge Solar Irrigation Project 

Solar Irrigation Facility)

– 150-200 kW Solar Powered– 23040 ft2 collector area

– Caloria HT-43, at 550 

oF in and 39

– 50,000 gal thermal storage
MSEP’s Past Experie

cont’d.

– ORC with Toluene and 

η=20%

– O&M required 4 hrs/day (2/3 of w

devoted to collector system)

– Plant operated automatically with 

during 1981-1982
MSEP’s Past Issue

• Diminished collector reflectivity over time• Equipment failure(pump seals, flexhose ru

piping, collector tracking, collector no-flow condenser freezing, tracker photodiodes cr

• Environmental issue: rainfall, storms, dust, • High O&M: cooling tower, collector system
MSEP’s Challenges and 

• Issues with operation of ORC’s a

temperatures 450 

oF to 580 

oF (c

appropriate working fluid)

• Availability of components for O• Development of new cycles
MSEP’s Challenges and 

• Development of modular solar p• Standalone operation of solar pla

costs)

• Balance between cost and efficie• Identification of potential marke• Identification of next action item