Flexibility Needed

As Costs are no longer the Bottleneck for more Renewables, attention shifts to Flexibility

Electric grids cannot store energy, so energy produced and consumed must match at any time. Fossil production could easily adapt to consumption changes. With weather dependent production it is more efficient if consumption follows production to avoid costly energy storage. This is called the “Paradigm Change”.

In “Energy Only Markets” electricity prices do not follow supply and demand instantly. Consumption and renewable energy production during a certain period define fossil power plant schedules. Short term deviations are balanced in the control power market using contracts with large power producers and consumers.

Unfortunately, with growing shares of volatile generation, such flexibility at the same time becomes more necessary and less available. When renewable generation exceeds demand, energy must even be destroyed (shedding).

Demand Side Management improves PV integration

The cheapest way to store energy is to use existing customer flexibility. In the past, there was no need to use it as fossil generation could supply the flexibility needed. Many energy applications do not need to draw energy at night when the sun is not shining: This includes heating and cooling applications, water treatment and pumping, and batteries that power electric vehicles. Here energy can be drawn from the grid at day time, while the output can be used around the clock. This is how the paradigm change can be implemented to make better use of solar energy production potential. 

Another possibility is to use decentral co-generation (CHP) of heat and electricity: it is easy to operate the plant at night to produce electricity when photovoltaic (PV) energy is not available, and store the heat that is co-generated with the electricity for use during the next days.