The Experts below are selected from a list of 1545 Experts worldwide ranked by ideXlab platform

D Santana - One of the best experts on this subject based on the ideXlab platform.

  • maximizing the Power block efficiency of solar tower plants dual pressure level steam generator
    Applied Thermal Engineering, 2018
    Co-Authors: Jesus Gomezhernandez, P A Gonzalezgomez, Javier Villa Briongos, D Santana
    Abstract:

    Abstract Solar tower plants (STP) are one of the most promising renewable technologies to substitute conventional Power plants. To further increase its penetration in electricity markets, it is necessary to maximize its efficiency. This work addresses the challenge of increasing the inlet pressure up to 165 bar at the high pressure turbine (HPT) to improve the Power block efficiency. Nowadays, these plants operate Rankine cycle with reheating using steam at 126 bar at the inlet of the HPT. This pressure is limited in current STP by the working temperatures of the molten salt, which range from 285 °C and 565 °C, the pinch point temperature difference in the evaporator and the current steam generator (SG) layout. A new steam generator design with dual-pressure level evaporation is proposed. The heat exchangers that form the SG are designed thermomechanically and the Power cycle performance is analyzed using the first and second laws of thermodynamics. The results show that the novel dual-pressure level SG layout increases the Power block efficiency from 44.14% to 44.64%. Assuming a market pricing scenario of two-tier tariff and a Power Purchase Agreement price of 16.3c€/kWhe, the new SG layout yields an extra economic benefit of 623 k€ per year due to an increase of energy produced of 5.71 GWhe/year.

Surachai Chaitusaney - One of the best experts on this subject based on the ideXlab platform.

  • a novel methodology for designing solar Power Purchase Agreement of rooftop pvs under the behind the meter scheme
    Energy Reports, 2020
    Co-Authors: Chawin Prapanukool, Surachai Chaitusaney
    Abstract:

    Abstract With a great reduction in the cost of rooftop photovoltaic systems (PVs), many new business models of PVs and the behind-the-meter scheme (BTMS) have been launched, especially the solar Power Purchase Agreement (SPPA). The SPPA is a model that the potential investors supply and sell the PV output Power to customers with the discount rates, directly. If the excess energy supplied to the grid is allowable, the investors will get additional revenue from the reverse Power. The proposed rates from the investors are practically formulated in term of the SPPA discount rates on utility’s retail rate. Therefore, to convince the customers while retaining revenue of the investors, attractive and feasible SPPA discount rates should be investigated thoroughly. The proposed methodology in this paper to determine the SPPA discount rates for rooftop PVs under the SPPA and BTMS is presented. The cost optimization was developed and proposed to minimize the SPPA electricity charges while maintaining an acceptable internal rate of return (IRR). The benefit of the customers is the lower electricity charges, while the benefit of the investors is the sold Power from rooftop PVs. Furthermore, with the proposed methodology, the large general service load in Thailand to assess the effect of the rate of excess energy and size of rooftop PVs. From the result, it showed that an oversized rooftop PVs will restrict the SPPA discount rates. The customers will get the higher SPPA discount rate if the rate of excess energy increases.

  • designing solar Power Purchase Agreement of rooftop pvs with battery energy storage systems under the behind the meter scheme
    Energies, 2020
    Co-Authors: Chawin Prapanukool, Surachai Chaitusaney
    Abstract:

    With a significant growth of rooftop photovoltaic systems (PVs) with battery energy storage systems (BESS) under the behind-the-meter scheme (BTMS), the solar Power Purchase Agreement (SPPA) has been developed into one of the most attractive models. The SPPA is a scheme where the investors propose to directly sell electricity from rooftop PVs to the customers. The proposed rates are typically performed in terms of the discount rates on the time-of-use (TOU) tariff with demand charges. The operation modes of the BESS should also be designed in accordance with the proposed rates. Therefore, this paper proposes a methodology to design the discount rates and operation modes of the BESS which will minimize the electricity charges of the customers while maintaining the revenue of the investors under the SPPA and BTMS. The reverse Power flow is considered as additional revenue to the investors. This paper also implements the proposed methodology with tariff structure in Thailand. The result showed that the installed capacity of rooftop PVs and battery capacity directly affect the discount rates and operation modes of the BESS. The rate of excess energy also has a significant impact on the discount rates but not affect the operation modes.

Jesus Gomezhernandez - One of the best experts on this subject based on the ideXlab platform.

  • maximizing the Power block efficiency of solar tower plants dual pressure level steam generator
    Applied Thermal Engineering, 2018
    Co-Authors: Jesus Gomezhernandez, P A Gonzalezgomez, Javier Villa Briongos, D Santana
    Abstract:

    Abstract Solar tower plants (STP) are one of the most promising renewable technologies to substitute conventional Power plants. To further increase its penetration in electricity markets, it is necessary to maximize its efficiency. This work addresses the challenge of increasing the inlet pressure up to 165 bar at the high pressure turbine (HPT) to improve the Power block efficiency. Nowadays, these plants operate Rankine cycle with reheating using steam at 126 bar at the inlet of the HPT. This pressure is limited in current STP by the working temperatures of the molten salt, which range from 285 °C and 565 °C, the pinch point temperature difference in the evaporator and the current steam generator (SG) layout. A new steam generator design with dual-pressure level evaporation is proposed. The heat exchangers that form the SG are designed thermomechanically and the Power cycle performance is analyzed using the first and second laws of thermodynamics. The results show that the novel dual-pressure level SG layout increases the Power block efficiency from 44.14% to 44.64%. Assuming a market pricing scenario of two-tier tariff and a Power Purchase Agreement price of 16.3c€/kWhe, the new SG layout yields an extra economic benefit of 623 k€ per year due to an increase of energy produced of 5.71 GWhe/year.

Chawin Prapanukool - One of the best experts on this subject based on the ideXlab platform.

  • a novel methodology for designing solar Power Purchase Agreement of rooftop pvs under the behind the meter scheme
    Energy Reports, 2020
    Co-Authors: Chawin Prapanukool, Surachai Chaitusaney
    Abstract:

    Abstract With a great reduction in the cost of rooftop photovoltaic systems (PVs), many new business models of PVs and the behind-the-meter scheme (BTMS) have been launched, especially the solar Power Purchase Agreement (SPPA). The SPPA is a model that the potential investors supply and sell the PV output Power to customers with the discount rates, directly. If the excess energy supplied to the grid is allowable, the investors will get additional revenue from the reverse Power. The proposed rates from the investors are practically formulated in term of the SPPA discount rates on utility’s retail rate. Therefore, to convince the customers while retaining revenue of the investors, attractive and feasible SPPA discount rates should be investigated thoroughly. The proposed methodology in this paper to determine the SPPA discount rates for rooftop PVs under the SPPA and BTMS is presented. The cost optimization was developed and proposed to minimize the SPPA electricity charges while maintaining an acceptable internal rate of return (IRR). The benefit of the customers is the lower electricity charges, while the benefit of the investors is the sold Power from rooftop PVs. Furthermore, with the proposed methodology, the large general service load in Thailand to assess the effect of the rate of excess energy and size of rooftop PVs. From the result, it showed that an oversized rooftop PVs will restrict the SPPA discount rates. The customers will get the higher SPPA discount rate if the rate of excess energy increases.

  • designing solar Power Purchase Agreement of rooftop pvs with battery energy storage systems under the behind the meter scheme
    Energies, 2020
    Co-Authors: Chawin Prapanukool, Surachai Chaitusaney
    Abstract:

    With a significant growth of rooftop photovoltaic systems (PVs) with battery energy storage systems (BESS) under the behind-the-meter scheme (BTMS), the solar Power Purchase Agreement (SPPA) has been developed into one of the most attractive models. The SPPA is a scheme where the investors propose to directly sell electricity from rooftop PVs to the customers. The proposed rates are typically performed in terms of the discount rates on the time-of-use (TOU) tariff with demand charges. The operation modes of the BESS should also be designed in accordance with the proposed rates. Therefore, this paper proposes a methodology to design the discount rates and operation modes of the BESS which will minimize the electricity charges of the customers while maintaining the revenue of the investors under the SPPA and BTMS. The reverse Power flow is considered as additional revenue to the investors. This paper also implements the proposed methodology with tariff structure in Thailand. The result showed that the installed capacity of rooftop PVs and battery capacity directly affect the discount rates and operation modes of the BESS. The rate of excess energy also has a significant impact on the discount rates but not affect the operation modes.

Javier Villa Briongos - One of the best experts on this subject based on the ideXlab platform.

  • maximizing the Power block efficiency of solar tower plants dual pressure level steam generator
    Applied Thermal Engineering, 2018
    Co-Authors: Jesus Gomezhernandez, P A Gonzalezgomez, Javier Villa Briongos, D Santana
    Abstract:

    Abstract Solar tower plants (STP) are one of the most promising renewable technologies to substitute conventional Power plants. To further increase its penetration in electricity markets, it is necessary to maximize its efficiency. This work addresses the challenge of increasing the inlet pressure up to 165 bar at the high pressure turbine (HPT) to improve the Power block efficiency. Nowadays, these plants operate Rankine cycle with reheating using steam at 126 bar at the inlet of the HPT. This pressure is limited in current STP by the working temperatures of the molten salt, which range from 285 °C and 565 °C, the pinch point temperature difference in the evaporator and the current steam generator (SG) layout. A new steam generator design with dual-pressure level evaporation is proposed. The heat exchangers that form the SG are designed thermomechanically and the Power cycle performance is analyzed using the first and second laws of thermodynamics. The results show that the novel dual-pressure level SG layout increases the Power block efficiency from 44.14% to 44.64%. Assuming a market pricing scenario of two-tier tariff and a Power Purchase Agreement price of 16.3c€/kWhe, the new SG layout yields an extra economic benefit of 623 k€ per year due to an increase of energy produced of 5.71 GWhe/year.