Power plants could cut a third of their emissions by using solar energy
If part of the fuel used by a power plant is replaced with solar energy, power plant emissions will be reduced. This is also required in order to meet the emission reduction targets. The COMBO-CFB project − Combination of concentrated solar power (CSP) with circulating fluidized bed (CFB) power plants − examined how various types of hybrid plant solutions can produce power flexibly according to demand, without the need for energy storage.
The concept in which steam generated by a solar field was fed directly into the power plant’s high-pressure turbine brought a reduction in emissions and fuel consumption which, at best, exceeded 33 per cent. Furthermore, a reasonable dimensioning of the hybrid plant and process optimisation can bring efficiency benefits as compared to the use of separate power production methods.
In a hybrid power plant, solar energy production which varies with weather is balanced by using a steam boiler. The production concepts developed through this project will expand the application possibilities of the CSP technology.
The dynamic nature of a hybrid process poses challenges to production system design and operation, particularly when the share of solar energy in power production is high. The COMBO-CFB project examined these challenges by using the Apros software designed for dynamic modelling, as well as through combustion tests conducted by using VTT’s pilot equipment in Jyväskylä, Finland.
The process can be further improved by attaching predictive control system and a short-term solar irradiance forecast. In the COMBO-CFB project, Vaisala developed a cloud camera which identifies cloud movements in the sky in order to increase the accuracy of the solar irradiance forecast for the area.
The implementation of the CSP technology in power production is reasonable in areas with an abundance of sunlight like the Mediterranean countries. However, this technology can also be implemented in areas with less sunlight by using hybrid power plants in which solar power is supported by another form of energy. Denmark is already using a CSP-bio hybrid plant to produce district heating.
Project partners to VTT was Telog, Pöyry, Finnish Energy and the Federation of Finnish Technology Industries. Project manager was Matti Tähtinen and research scientist was Elina Hakkarainen.
Concentrated solar power (CSP) technology
Concentrated solar power is a renewable energy technology that can be used to produce both electricity and heat. Other applications include for example desalination. The CSP technology involves the concentration of energy contained by sunlight by using mirrors. This energy is converted into heat that runs the turbine, similarly to traditional power plants. Unlike in traditional power plants, however, the power production varies depending on the irradiance level.
Final report: http://www.vtt.fi/inf/pdf/technology/2017/T296.pdf
Apros simulation tool: http://www.apros.fi/en/
CAPTION:The project accumulated knowledge about the CSP technology by visiting internationally renowned commercial and test plants, as well as through research exchange with the German Aerospace Center (DLR). Photo: The Puerto Errado plant in Calasparra, Spain.
VTT Technical Research Centre of Finland Ltd is a leading research and technology company in the Nordic countries. We use our research and knowledge to provide expert services for our domestic and international customers and partners, and for both private and public sectors.
@This article is published by conbio.info 2017-05-09 and based on a press release which has ben edited by Lennart Ljungblom. conbio.info is focusing on news that may have an impact on bioenergy business and also bioenergy news with impact on society and other relevant areas, on line since 2013.