Energy conversion/Description: Difference between revisions

From IMAGE
Jump to navigation Jump to search
No edit summary
No edit summary
Line 34: Line 34:
The costs of solar and wind power are the model determinedby learning and depletion dynamics. For renewable energy, costs relate to capital, O&M and system integration. The capital costs mostly relate to learning and depletion processes (learning is depicted in learning curves, see Box X; depletion is shown in cost–supply curves).  
The costs of solar and wind power are the model determinedby learning and depletion dynamics. For renewable energy, costs relate to capital, O&M and system integration. The capital costs mostly relate to learning and depletion processes (learning is depicted in learning curves, see Box X; depletion is shown in cost–supply curves).  


The additional system integration costs relate to 1) discarded electricity in cases where production exceeds demand and the overcapacity cannot be used within the system, 2) back-up capacity, and 3) additional, required spinning reserve. The two last items are needed to avoid loss of power if the supply of wind or solar power suddenly drops, enabling a power scale up in a relatively short time, in power stations operating below maximum capacity (Hoogwijk, 2004).
The additional system integration costs relate to 1) discarded electricity in cases where production exceeds demand and the overcapacity cannot be used within the system, 2) back-up capacity, and 3) additional, required spinning reserve. The two last items are needed to avoid loss of power if the supply of wind or solar power suddenly drops, enabling a power scale up in a relatively short time, in power stations operating below maximum capacity ( [[Hoogwijk, 2004]]).
*To determine discarded electricity, the model makes a comparison between 10 different points on the load-demand curve, at the overlap between demand and supply. For both wind and solar power,  a typical load–supply curve is assumed (see Hoogwijk, 2004). If supply exceeds demand, the overcapacity in electricity is assumed to be discarded, resulting in higher production costs.  
*To determine discarded electricity, the model makes a comparison between 10 different points on the load-demand curve, at the overlap between demand and supply. For both wind and solar power,  a typical load–supply curve is assumed (see Hoogwijk, 2004). If supply exceeds demand, the overcapacity in electricity is assumed to be discarded, resulting in higher production costs.  
*Because wind and solar power supply is intermittent (i.e. it varies and therefore is not reliable), the model assumes that so-called back-up capacity needs to be installed. For the first 5% penetration of the intermittent capacity, it is assumed that no-back is required. However, for higher levels of penetration, the effective capacity (i.e. degree to which operators can rely on plants producing at a particular moment in time) of intermittent resources is assumed to decrease (referred to as the capacity factor). This decrease leads to the need of back-up power(by low-cost options, such as gas turbines), the costs of which are allocated to the intermittent source.
*Because wind and solar power supply is intermittent (i.e. it varies and therefore is not reliable), the model assumes that so-called back-up capacity needs to be installed. For the first 5% penetration of the intermittent capacity, it is assumed that no-back is required. However, for higher levels of penetration, the effective capacity (i.e. degree to which operators can rely on plants producing at a particular moment in time) of intermittent resources is assumed to decrease (referred to as the capacity factor). This decrease leads to the need of back-up power(by low-cost options, such as gas turbines), the costs of which are allocated to the intermittent source.
Line 48: Line 48:
*Intermittence does not play an important role, as hydrogen can be stored to some degree. Therefore, there are no equations simulating system integration.
*Intermittence does not play an important role, as hydrogen can be stored to some degree. Therefore, there are no equations simulating system integration.
*Hydrogen can be traded. Therefore, a trade model is added, similar to the trade models for fossil fuels, as is described in the chapter on energy resources.
*Hydrogen can be traded. Therefore, a trade model is added, similar to the trade models for fossil fuels, as is described in the chapter on energy resources.
}}
}}

Revision as of 15:49, 18 November 2013