The single greatest problem that the Green Revolution faces is the amount of infrastructure needed to support it. I propose here a less centralized and more modular approach.
To begin with, at the height of the Auto Age there were 250,000 gas stations in the United States, each of which had an average roofing surface area of 5,000 square feet, with 50,000 square feet of total property size. The average solar panel generates 20 watts per square foot, and costs $1.00 per watt, in addition to $2.00 of installation fees, with an average lifetime of 30 years. The average cost per watt of energy in the United States is $0.15 as of this posting.
Putting all of these numbers together, there would be a total of 1.25 billion square feet of roofing available for solar panel installations in United States gas stations. To cover it all with panels would create 25 billion watts of energy at an initial cost of $75 billion in startup costs. Adjusting for the life of the solar panels, that comes out to $2.5 billion per year, or $0.10 per watt.
From here, there are two possible approaches. The first is to allow gas stations to work together, so that at any one point in time the panels which are receiving sunlight are able to supplement the electrical needs of panels which are in the dark.
The second approach is to install some form of energy storage device in each gas station, so that any one station can supply electricity from its own energy reserves between dusk and dawn. To store 12 hours of energy from 25 billion watts of solar panels would come out to 1.2 million watt-hours per gas station, and 300 billion watt-hours in total. Current battery costs are $100 per kilowatt-hour, which translates to $30 billion in total costs. Lithium batteries last for about 6 years, so it would average out to $5 billion per year, or another $0.20 per solar panel watt.
Alternatively, some hybrid approach combining the two above options can also be used, and is likely to be preferred, as it will increase the affordability of the infrastructure to a point where it will be cost competitive with other forms of energy. For instance, if only 3 hours of energy is stored instead, that would come out to 300,000 watt-hours per gas station, 75 billion watt-hours in total, $7.5 billion in total costs, $1.25 billion in yearly costs, and $0.05 per solar panel watt.
But would this all be enough energy to support an entire nation's worth of electric vehicles? At 25 billion watts, this option would generate 600 billion watt-hours of energy per day, and 219.15 trillion watt-hours in a year. An average electric vehicle travels on average 13,500 miles per year, and uses 4 million watt-hours of energy per year. So the proposed network would be able to support 55 million or so vehicles, or one fifth of the total number of vehicles in current operation within the United States.
Clearly additional space would be needed for a comfortable transition to an all-electric vehicle economy. If another 20,000 square feet of unused property at each gas station were to be converted into small solar farms, the total would rise to 125 billion watts, or 3 trillion watt-hours per day, and 1 quadrillion watt-hours per year. This would be enough to safely service 275 million electric vehicles. And with $0.10 per watt in solar costs plus $0.05 per watt in battery storage, it would remain cost competitive with traditional forms of energy.
The only question left to be answered is whether service stations can have the ability to safely transfer such an extraordinary amount of electrical energy to the vehicles they are servicing. If AC-DC adapters are used, as they currently are, then the wait times would be prohibitively long. Fortunately however, the technology already exists to bypass the reliance on Direct Current, and instead directly convert an Alternating Current into electrical storage. This can theoretically be used both to store solar charge in the service station's lithium batteries, and to rapidly transfer that energy into the customers' electric vehicles. With the cooperation of electric vehicle manufacturers, charging times can therefore be significantly reduced, from hours to minutes.
In conclusion, at a lifetime amortized cost of $0.15 per watt, existing infrastructure can very easily and affordably be retrofitted to accommodate the electric vehicles of the future.
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