When they calculate that Solar + battery would cost $50-131/MWh, how is that number reached? What is the number of charge cycles and over what time span? It seems obvious that the cost of producing, installing and operating a 1MWh system of solar and batteries will cost more than a one time payment of $50-131.

Most of the time when I try to find any data there is the underlying assumption that the charge cycle is a day and night cycle, where the day produce the energy needed during the night, and not a seasonal storage that basically has a single charge cycle per year.

Those are American prices with tariff insanity.

It is much cheaper in the rest of the world. Recent Chinese storage prices are down to ~$50/kWh.