L R AS Published on Sunday 1 December 2019 - n° 300 - Categories:power plants
Analysing hybrid power plants in another way
The American NREL has been studying the potential of hybrid power plants that combine wind, solar and storage. The development of such plants is driven by the need to increase profitability and to take into account parameters beyond the discounted cost of electricity, taking into account time-varying revenues and better managing the variability inherent in renewable energy.
Once RE accounts for 10-20% of total electricity production, the cost of energy should no longer be considered, but should include other criteria that maximise profitability. This is essential because RE is increasingly in competition with traditional sources of energy production. The plant owner needs to pay attention to the savings to be made on land use costs, electrical and physical infrastructure, and operational expenses. The plant owner should also increase the value of the facility to capitalize on revenue streams through forward capacity markets (where appropriate), dispatchable operation in markets where energy prices vary over time, and ancillary services (where appropriate).
The main factor in a renewable energy installation is the quality of the resources that are provided and their distribution over time. At present, however, most plants are designed around energy sales contracts with the main objective of minimising the cost of energy. For NREL, this approach is outdated. The characteristics of the energy resources and the market in which the system delivers electricity should be taken into account.
NREL states that "the complexity and uncertainties inherent in optimising the physical design of hybrid power plants go beyond current practice". The full potential of future low-cost, high-value hybrid power plants for the electricity grid must be realized.
PV Magazine of 28 November
Editor's note A new stage of reflection has been reached with this observation: it is not enough to obtain the lowest price for wind or solar electricity. It is necessary to take into account the intermittency as well as the cost of the installations. It is therefore necessary to determine what is most profitable for the electricity company, which will be obliged to compensate for the intermittency, to make the energy travel, and to pay to install and operate the production infrastructure. We move from a consideration of the gross energy produced (solar kWh versus gas or nuclear kWh), to a global cost price that takes into account all the production factors in order to determine a cost price. This is both more realistic and also a second step in the design of renewable energies that compete with other energy sources.
