Economy & Energy
Year XV-No 92
Is it Possible Electric Energy Shortage in 2014?
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Is it Possible Electric Energy Shortage in 2014?
Monitoringing the situation of the hydroelectric reservoirs until March 31, 2014.
The situation of the reservoirs that accumulated hydro energy in March 2014 is worrisome and there is the possibility of electric energy shortage in the country this year. As it did last year, E&E has been warning about this possibility.
Measures regarding supply and demand are necessary to prevent this shortage in the National Integrated System.
The first quarter of 2014 is the driest one along eighty years and an evaluation based on this quarter indicates a probability higher than 50% of energy shortage.
Monitoring: Situation in 07/16/2014
Situation of reservoirs in 07/16/2014 compared to projections of 03/31/2014; Present stock is 41.9%. Rainfalls in June (inflow above the historical average) and reduction of the level consumption in the two previous years have stabilized the stock of the month. Real behavior, which was below the limit (that would lead to rationing), is now above it. The path is better than that considered as probable considering the statistics of the first three months of 2014 (see note 17/05).
João Antonio Moreira Patusco
Due to its continental dimensions, each Brazilian state has peculiar characteristics regarding economic, social and energy use sectors which makes them different from each other.
The article shows these characteristics, focusing mainly on analyzes and comparison of energy indexes related with socio-economy and particles emissions of this Federation Unit with that of Brazil and of the other states. The ranking concerning 30 indexes of the Amazon state and of the other states is presented.
Data until May 15 confirm the risk of electricity deficit in the National Integrated System in 2014
Carlos Feu Alvim
The risk of deficit regarding electricity supply or of “blackout” in 2014 is real and the Federal Government itself admits it but estimates that it is lower than 5%. This probability evaluation apparently does not consider that there is a correlation between the rainfalls in the first quarter of the year and in the rest of the year, as shown in this issue of E&E (Figure 5), reproduced below as Figure 1. Years that have a dry first trimester are usually dry in the rest of the year
This is due in part to climate conditions. The 2014 rainfalls were well below expectations and the water that flows into the reservoirs for electricity generation is 30% below the expected value.
Figure 1: Correlation between the average flow in the first trimester and in the rest of the year
When this correlation and the average deviation are considered, the expected inflow value in 2014 is 43 ± 4 GW.year. Using this value, one can produce a curve that indicates the probable stock path which is shown in Figure 2. In this path, indicated as probable, there will be a supply deficit of 9GW at the end of this year.
In a certain way this was accomplished in the last auction when the aluminum industry decided to sell the electricity it produces for its own use. The appointed solution would not necessarily eliminate the deficit because the process is statistical and it can happen that the deficit will be higher than the one foreseen as well as that there will be higher rainfall and so it would be verified a posteriori that no restrictions were necessary. Since the chance that this need is higher than 50%, some preventive measures should be taken.
Figure 2 shows that the projection made using data up to March 31 is being confirmed.
Extrapolation using data until March 31 that is confirmed in the two
subsequent months and that foresees the possibility of supply deficit at
the end of 2014
In the upper part of Figure 2 the graphic shows that the stock has been reduced along the years; besides the “probable” scenario, the basic scenario (average historical months inflow) and the limit scenario (inflow just necessary to satisfy the foreseen demand) projections are also shown in detail.
Conclusion: Considering the correlation between the first trimester and the rest of the year, the probability of rationing in 2014 is about 50% and measures that would induce consumption reduction and/or supply increase are necessary to prevent non-programmed interruptions and restore the system for the next year. If the adequate sectors are chosen and the process is started early, the economic loss might not be significant.
Causes and possible countermeasures
The situation in 2014 it the result of water inflow decrease which is one of the highest in the historical series and of a year – 2012- with very low rainfall and 2013, slightly lower than the average. The lack of rainfall was this year concomitant with an increase of atmospheric temperature which stimulates the use of air conditioning. Demand was 4% higher than that foreseen for the first quarter of the year. The conjunction of these factors caused the decrease to 42% of reservoirs’ capacity which would normally be full.
In Figure 2, in the right axis, it is indicated the stock in GW.year (energy generated by an average 1GW source during a year). This unit permits to represent in simple numbers what occurs in our electric system.
The Brazilian reservoirs can accumulate energy to generate about 24 GW during a year. The stock accumulated at the beginning of the year was 10GW.year which, instead of growing until the middle of the year as usual, remained practically stable.
As it has been seen, the foreseen water inflow based on the rainfall of the first trimester is 43GW.year, excluding the losses (outflow energy) of about 5 GW.year, an average of 38GW remains, which is insufficient to satisfy the foreseen demand of 64 GW.year. Even taking into account 16GW.year from other sources, (38+16=54) GW.year, it is necessary a surplus of 10GW.year to satisfy the demand. As we have verified, this is just the stock available at the beginning of the year and the situation is very close to the limit, that is, we run the risk of using it up until the end of the dry season in November.
The use of this unit also permits to appreciate in a simplified way the balance of the present system. In a normal year the average inflow in the set of reservoirs is 59 GW.year, subtracting the losses, and 54GW.year would be available. To satisfy a demand of 64 GW.year it is necessary a firm energy generation of 10 GW.year.
Much has been said about the fact that the use of thermal plants has generated the need of increasing tariffs but it should be no surprise the need of generating 10 GW on the average during the year since this is already a normal demand.
In the Brazilian system the hydroelectric plants should have the capacity of satisfying the demand oscillations along the day (higher in the late afternoon) and along the week (higher in the working days). This is due to the extraordinary flexibility of these plants to vary the generated energy. However, this demand is rather due to its generation capacity than to long term storage.
The long term capacity of hydroelectric plant reservoirs meets the mentioned demand oscillations, but it was conceived to regulate the seasonal variations of water supply, most of them associated with the rainfall regime. In the present configuration, in a normal year, 11GW.year is necessary to regulate the system. That is, the reservoirs, which have 24GW.year of capacity, use about 11 GW.year to satisfy the seasonal variation of rainfalls.
In the past, the storage capacity relative to that of generation was much bigger and the system also regulated the occurrence of dry years. Presently, to satisfy alterations due to these years, 13 GW.year is left. A decrease of 30% in inflow means a reduction of water supply of 18GW.year which cannot be satisfied by the reservoirs and more 5 GW.year of thermal capacity would be necessary (besides 10 GW.year of the already mentioned firm energy). Considering also 1 GW.year of the reservoir’s dead storage it would be necessary an average of 16GW. This is just what the system can presently generate with other sources. In some years, the system’s administrators did not activate the thermal plants in time and so the problem arose. But this did not occur this year since practically all the thermal capacity was activated.
That is, even if the system has the initial stock necessary for the maximum value (which did not occur in 2014), an inflow reduction of 30% in only one year is the limit that it can presently absorb. The system is prepared to face only one dry year. A series of dry years such as that we have now cannot be managed by the present system.
In the future it is necessary to provide the system with the necessary base generation complementation, presently about 10GW firm energy. For the time being, consumption reduction or increasing supply by a little more of 1 GW monthly might solve the problem in the following months in the scenario considered here as the probable one. This can be achieved by inducing the energy-intensive industries such as the aluminum and ferroalloys industries to reduce their energy demand. The deficit risk would be reduced but not eliminated.
Graphic Edition/Edição Gráfica:
Tuesday, 23 September 2014.