One major problem with wind and solar energy is that they are conditional. Explain how hydroelectric pumped storage could be used to eliminate this obstacle? *​
Link to the article https://thinkprogress. org/the-inside story-of-the-worlds-biggest-battery -and-the-future-of-renewable-energy -8984c81283c/

Hydroelectric pumped storage can be used to eliminate the conditional nature of wind and solar energy. At times of peak production of energy from either solar or wind (during summer and windy days), the excess electrical energy produced can be stored using hydroelectric pumped storage methods. When conditions no longer favour energy production from either wind or solar sources, these stored energy can then be regenerated for use.

Explanation:

Pumped-storage hydroelectricity is a type of hydroelectric energy storage used by electric power systems to store excess electrical power during periods of low demand for later release at periods when demand for energy rises again. It stores energy in the form of gravitational potential energy of water, pumped from a lower level reservoir to a higher level reservoir.

At times of low electrical demand, excess generated energy is used to pump water into the upper reservoir. When there is higher demand, water is released back into the lower reservoir through a turbine, generating electricity.

This form of energy storage is useful in circumventing the conditional nature of renewable energy sources such as wind and solar energy. At times of peak production of energy from either solar or wind (during summer and windy days), the excess electrical energy produced can be stored using hydroelectric pumped storage methods. When conditions no longer favour energy production from either wind or solar sources, these stored energy can then be regenerated for use.

assuming that your periodic table has eighteen columns, you should highlight   the four elements in the third column from the left of the table.

neutral atoms of elements after calcium contain d electrons. the energy of d orbitals of a particular main shell lies between the energy of the s and p orbitals of the next main shell. for example, electrons in the have energy higher than those in the orbital while lower than those of the orbital.

by the aufbau principle, electrons fill orbitals one at a time, starting from those of the lowest energy. the orbital is therefore filled right after orbitals and before orbitals.  

potassium has electron configuration and calcium . the s orbital of a main shell holds a maximum of two electrons. the next element would thus have the electron configuration and satisfy the requirements.

a neutral atom of the element contains three electrons on top of the most recent noble gas element. it should thus be placed in the third column of the periodic table. both scandium and yttrium would satisfy the conditions. an aufbau diagram indicates that the 4f orbital is filled before the 5d. however, it appears that exceptions exists for both lanthanum and actinium. neutral atoms of the two d-block elements also demonstrate the and should be highlighted as well.