ybrid Solar and Fossil ower Generation by Justin Zachary, hd Bechtel ower orporation Frederick, Maryland USA resented at Solar ower International 09 Anaheim, A 8907 10/09 1
Outline oncentrated Solar Thermal Types Trough Tower Linear Fresnel ybrids onfigurations Integrated Solar ombined ycle (IS) Integrated Solar Rankine ycle Desalination onclusions and Recommendations 8907 10/09 2
oncentrated Solar Thermal Options arabolic Trough Medium Temperature: 698 F 725 F (370 385 ) entral Tower and eliostats igh Temperature >932 F (500 ) Linear Fresnel Low Temperature: 482 F 572 F (250 300 ) 8907 10/09 3
Summary of the S Technologies Technology Type Tower Trough Linear Fresnel Working Fluid Temperature Steam Synthetic Oil TF Steam ~1022 F (550 ) ~716 F (380 ) ~518 F (270 ) (or higher) 8907 10/09 4
ybrid Solar and ombined ycle lants 8907 10/09 5
Why Integrate Solar and Fossil? liminates concern over the intermittent nature of solar energy an be used to either increase power or reduce fuel consumption Incremental cost increases in steam cycle equipment are smaller than for standalone solar facility 8907 10/09 6
Integrated Solar ombined ycle 8907 10/09 7
IS for igh Temperature ~1022 F (550 ) S V I R Solar Field Gas Turbine A Steam Turbine I S I V L V L T L S Fuel Air eat Recovery Steam Generator Solar Field Steam Generation lose to Main Steam onditions 8907 10/09 8
IS Medium Temperature ~716 F (380 ) Design riteria The most efficient use of solar energy is supplementing saturated steam generation The least efficient use of solar energy is feedwater preheating or steam superheating 8907 10/09 9
IS for Medium Temperature ~716 F (380 ) S V I R Solar Field Gas Turbine A Steam Turbine I S I V L V L T L S Fuel Air eat Recovery Steam Generator Solar Field Generated Steam Goes to Superheater 8907 10/09 10
IS for Low Temperature S V I R Solar Field Gas Turbine A Steam Turbine I S I V L V L T L S Fuel Air eat Recovery Steam Generator Solar Field Generated Steam Goes to old Reheat Line 8907 10/09 11
urrent IS rojects roject Location Solar Technology lant Output Solar ontribution Kureimat gypt Trough 140 MWe 20 MWe Victorville alifornia Trough 563 MWe 50 MWe almdale alifornia Trough 617 MWe 62 MWe Ain Beni Mathar Morocco Trough 472 MWe 20 MWe assi R'Mel Algeria Trough 130 MWe 25 MWe Yazd Iran Trough 430 MWe 67 MWe Martin Solar Florida Trough 480 MWe 75 MWe Agua rieta Mexico Trough 480 MWe 31 MWe 8907 10/09 12
ybrid Solar and Steam ycle lants 8907 10/09 13
Integrated Solar With Rankine ycle igh Temperature Above 1,022 F (550 ) For subcritical plants, S steam is directly mixed with main steam from the fossil boiler to the turbine It is expected that the next generation of power tower boilers could produce supercritical steam for direct injection Solar boilers with two pressure circuits could be also connected to the hot reheat I steam. 8907 10/09 14
Integrated Solar With Rankine ycle igh Temperature Above 1,022 F (550 ) Steam Turbine Solar Field A Boiler Feedwater eaters 8907 10/09 15
Integrated Solar With Rankine ycle Medium Temperature ~716 F (380 ) Direct integration of S steam in the coal fired boilers is complex and requires sophisticated controls S generated steam is used to displace steam extractions to the feedwater heaters. Reducing the boiler load slightly increases efficiency, thus yielding additional fuel savings 8907 10/09 16
Integrated Solar With Rankine ycle Medium Temperature ~ 716 F (380 ) Steam Turbine Solar Field A Boiler Feedwater eaters 8907 10/09 17
ontrol and Transient Behavior hallenges ybrid system must include in depth analysis of the transient behavior of the entire system Lack of experience with utility scale IS, operating scenarios (startup, shutdown, and solar transients) must be modeled and control schemes developed to protect component integrity While predictable, the intermittent nature of S steam creates a new set of requirements for conventional equipment integration 8907 10/09 18
ybrid Solar, Including MD Desalination arabolic Trough ower lant with Oil Steam Generator and MD Desalination arabolic Trough ower lant with Oil Steam Generator and MD Desalination Solar Field Steam Turbine Solar Superheater MD System Steam Generator Seawater Solar reheater Brine Deaerator xpansion Vessel 8907 10/09 19
ybrid Solar, Including RO Desalination arabolic Trough ower lant with Oil Steam Generator and SWRO Desalination 8907 10/09 20
ybrid Summary Integration of S with conventional fossil plants minimizes the effect of the intermittent nature of the solar energy supply. The addition of S to new and existing plants improves efficiency and reduces the carbon footprint. Sizing optimum solar field is a site specific task, based on available real estate and equipment capacity. 8907 10/09 21
Questions? jzachary@bechtel.com 8907 10/09 22