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Reduce the price of electricity by 15% by moving to planning on a daily average basis

EITAN PELED's picture

Education: Industrial Engineering and Management, MBA, LLB. Initiation and development of energy management systems in complexes and high-rise buildings. Establishment of a system for energy-zero...

  • Member since 2021
  • 19 items added with 3,902 views
  • Feb 7, 2022

The State of Israel has decided to base itself on solar systems as a basis for the transition to green energy. According to the government decision, the target is to reach 30% solar energy by 2030 and 70% - 80% solar energy by 2050.

Examining the volume of storage required to meet these targets requires the construction of facilities of about 36GWh by 2030 and the scope of about 200GWh by 2050. In a holistic view, the role of storage facilities is to adjust solar energy production to demand on the one hand and to match demand to production on the other. This can be achieved by setting up storage facilities as part of the solar fields on the one hand and installing storage facilities in the built-up areas on the other.

Another factor to consider is the fossil array required to complete demand and secure production. As the volume of photovoltaic production increases, production in the fossil array decreases and the efficiency of gas turbines decreases significantly. Today, the efficiency of the fossil array in Israel is about 53% and in the future is expected to fall below 25%. On the other hand electricity should be ensured during the winter when there is no sun. During these periods the scope of the fossil array should ensure all demand. (Israel is an energetic island and has no neighbors to rely on during periods of lack of sunshine).

The third factor to consider is the need to move the solar energy, generated mostly in the open spaces, to the urban and industrial consumers located within the cities. This transportation requires the establishment of large-scale high-voltage transmission infrastructure,

The planning principles of the electricity economy in the world and in Israel are based on the peak of annual demand and the peak of multi-year demand. The basic premise is that demand cannot be controlled and therefore the production, transmission and distribution system must adapt to the changing demand. Analysis of the annual demand graph shows that the peak demand (the last 1,000MWh) takes place for about 150 hours a year (out of 8,760 hours a year) about 2% of the time.

Because daily demand forecasts are inaccurate and there is a possibility that a large production facility is out of order, the need for a 19% reserve above the peak demand (daily and annual) was defined as a basis for ensuring power supply and limiting power outages below 3.5 hours per year.

The entry storage facilities (required to balance solar production) into the electricity system opens up the possibility of switching from planning based on the peak of consumption (daily and annual) to planning based on the average consumption (daily and annual average peak). Analysis of the annual solar production curve shows that if we store 50% of the energy generated in the solar fields, the efficiency of the storage facilities will be only about 20%! In summer, when solar production is at its peak, the storage facility is charged for about 5 hours and unloaded for 4 hours in the evening, a total of 9 hours out of 24 (38%) and in winter there is not enough sun and the storage facilities are not active for about five months in total.

Efficient planning of the use of storage facilities shows that they can be used simultaneously for the treatment of the daily reserve required to balance deviations in demand forecasts (currently about 2GWh for 5 hours total 10GWh and in 2030 about 3GWh for 5 hours total 15GWh in daily cycle).

A second parallel use is the balance of the fossil array to the average daily consumption and the peak of the annual daily average consumption. Analysis of the demand curve at the peak of consumption in the winter without sun shows that the daily average in 2030 will be about 14GWh and therefore there is no need to expand the fossil array and it can be reduced by 4GW (currently the array size is about 18GW - 20% reduction).

Planning the scope of the fossil array required for 2030, based on the peak of demand, shows that it should be increased to 23GW (current operation + reserve). And if we move to a daily average base and transfer a significant portion of the reserve to the storage facilities, the size of the array will be 16GW, saving 7GW! In order to implement this design, a storage system of about 45GWH is required (overlaps by 75% for the storage system required for solar production in 2030) and with the expansion of solar production, it is embedded in it and does not require storage facilities beyond what is required for solar energy storage.

In choosing the location of the storage facilities, they should be divided between their installation in the solar fields (when they serve the storage of solar energy, the reserve and also the balance of the fossil array) and their installation in their built-up area. The installation of solar facilities in built-up areas meets several needs simultaneously: for the national system - balancing the transmission and distribution network while lowering the planning base to the average annual daily peak (instead of the annual peak), as part of the reserve, balancing the fossil array and collecting energy from the photovoltaic facilities on the roofs. And for the residents of the neighborhood: UPS - prevention of power outages, solution for charging electric cars, and kosher electricity on Saturdays and holidays.

In a multi-year vision (until 2050) about 150GWh of the storage facilities will be installed in the solar fields and 50GWh of the storage facilities will be installed in the built-up areas.

The savings for the Israeli electricity economy can reach NIS 100 billion and more by the year 2050. (Reduction in electricity prices by about 15%).

Matt Chester's picture
Matt Chester on Feb 7, 2022

This seems to provide a grid-wise benefit-- as such do you think governments should look to support/incentivize energy storage like they have for years for tax credits for solar systems? 

EITAN PELED's picture
EITAN PELED on Feb 7, 2022

The government's support for solar energy rests on the need to reduce carbon emissions. In Israel the cost of solar energy is similar to the cost of gas turbines and in Europe the cost of solar energy is more expensive than the cost of fossil energy.
Moving to planning the energy system over the daily average instead of peak demand leads to significant savings in fossil system costs because turbines operate continuously at the same power and thus their efficiency increases significantly (in Israel this means an increase from 53% to 80% efficiency) and at the same time carbon emissions decrease. From this it is clear that in terms of the benefit to the consumer public the entry of storage facilities on a considerable scale into the cities is great and therefore the state should support this directly. (In Israel, the Electricity Authority is considering supporting the storage facilities in the built-up areas through availability payments based on the capacity of the facility + payment for its unloading and charging) In my opinion, this is the correct model for other countries as well.

EITAN PELED's picture
EITAN PELED on Feb 7, 2022

An obvious question is where to place the storage facilities in the built-up areas. Today the accepted approach is behind the electricity meter. This is an approach that is very limited in the scope of storage (depending on the ability of a low-voltage grid to conduct the energy to the national grid). The preferred connection of the storage facility should be twofold: on the one hand to the low voltage, to serve the neighborhood / building, and on the other hand to the high voltage, to serve the national network.

EITAN PELED's picture
EITAN PELED on Feb 7, 2022

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