The Election Commission will require around 30 lakh electronic voting machines (EVMs) and a preparation time of nearly one-and-half years for the smooth conduct of simultaneous elections to the Lok Sabha and state assemblies, sources have said.

An EVM comprises one control unit, at least one ballot unit and one voter verifiable paper audit trail (VVPAT) unit.

According to the sources, the commission will require nearly 30 lakh control units, about 43 lakh ballot units and about 32 lakh VVPATs for the simultaneous polls, taking into consideration the reserve units kept for replacement in case of any malfunction or damage.

Sources said there is a shortfall of nearly 35 lakh voting units -- control units, ballot units and VVPAT units -- for the simultaneous conduct of Lok Sabha and assembly polls.

As deliberations on the conduct of simultaneous polls gathered steam, the Election Commission had informed the Law Commission a few months ago that it would also require adequate warehousing facilities to store the electronic voting machines.

The Law Commission, which is working on a report on holding simultaneous elections to Lok Sabha and state assemblies, had organised an interaction with the EC on its requirements and challenges for holding synchronised polls.

Sources aware of the interaction said much would depend on the number of polling stations set up when such an exercise takes place. When Lok Sabha and assembly elections are held simultaneously in some states, voters cast their votes in two separate EVMs. In the last Lok Sabha elections, there were 12.50 lakh polling stations.

The commission now requires around 15 lakh control units, 15 lakh VVPAT units and 18 lakh ballot units for 12.50 lakh polling stations.

An EVM has shelf life of 15 years.

While there was no official estimate available on how much these voting units cost, at the previous procurement rates also the total cost for one crore units will be in excess of Rs 15,000 crore, including over Rs 6,500 crore for VVPAT units.

The cost can go even higher if local body polls are also held together with Lok Sabha and assembly polls.

The high-level committee on "one nation, one election" headed by former president Ram Nath Kovind is examining holding simultaneous elections to the Lok Sabha, state assemblies, municipalities and panchayats, keeping in view the existing framework under the Constitution and other statutory provisions.

According to sources, the poll watchdog in its interaction with the Law Commission also listed out challenges such as need for more warehousing facilities for EVMs.

Referring to the nearly one-and-half years of preparatory time, they said two public sector undertakings -- ECIL and BEL -- who manufacture EVMs would also need to be informed well in advance.

They said the semiconductor industry should also be stable to cater to the enhanced demand. When the interaction took place, there were problems related to the semiconductor industry which seem to have settled now, they pointed out.

The EC would also need time for "first-level check" (FLC) of EVMs before polls.

The EC has already commenced FLCs for the 2024 Lok Sabha elections in a phased manner across India.

During FLCs, EVMs, including VVPATs, machines are checked for mechanical flaws by engineers of Bharat Electronics Ltd. (BEL) and Electronics Corporation of India Ltd. (ECIL).

Faulty machines are returned to the manufacturers for repair or replacement. A mock poll is also held to check the two machines in the presence of representatives of political parties.