With lightning perhaps starting in ponds, it may have then spread to creeks, rivers and then the sea. Once enough complex organic compounds and minerals over millions of years have built up as a food source in the sea and on land for bacteria mosses and fungi and other smallish lifeforms to flourish then small creatures would eventfully come from the sea or from lakes to then evolve into bigger lifeforms.
This would make sense, as millions of years of nutrients, minerals, organic compounds and salts would make their way towards the sea spread by rain and floods.
How much lighting would be required to start life ?
There are 2,000 thunderstorms at any given moment worldwide. Lightning flashes more than 3 million times a day worldwide — that’s about 40 times a second or
1.4 billion strikes a year,
How to work out the Energy figures ?
1.4 billion (1,400,000,000) lighting strikes a year with each containing around one billion (1,000,000,000) joules of energy x 4.543 billion years (4,543,000,000, age of Earth).
so !.4 billion strikes x 1 billion joules of energy x 4.5 billion years.
That is not counting volcanic lightning or cloud to cloud lighting, red sprites, blue jets and green elves or other sources etc
These figures would need to be calculated as well as they would be creating gas oxidation etc
A typical lightning bolt contains 1 billion volts and contains between 10,000 to 200,000 amperes of current.
Each strike spreading ground currents from several meters to several hundred metres depending on the surface conductance rock, soil or water etc, creating fulgurites on sandy soils
Lighting also creates increased levels of ozone, some oxides and nitrogen, and those amounts would need to be calculated over the age of the Earth as well
A comparison between levels of Lightning (pre human created global warming) over 50,000 years ago needs to be worked out and compared with lightning levels 50,000 years to today.
Sources
A typical lightning bolt contains 1 billion volts and contains between 10,000 to 200,000 amperes of current.” But it generally it is only for microseconds so actual power compared to what we use normally is inconsequential.
https://www.quora.com/What-is-the-voltage-and-amperage-of-an-average-lightning-bolt
Lightning contains around one billion (1,000,000,000) joules of energy
https://www.realclearscience.com/blog/2012/05/could-we-harness-lightning-as-an-energy-source.html
1,400,000,000 strikes every year
https://www.metoffice.gov.uk/weather/learn-about/weather/types-of-weather/thunder-and-lightning/facts-about-lightning
Study shows lightning adds to ozone level
https://www.eurekalert.org/pub_releases/2003-03/tau-ssl031903.php