A complete eight-stall worked example, every line item

Most of the posts on this blog take one input and move it. This one moves nothing. It is the engine's default scenario, laid out line by line, so that every figure quoted elsewhere has a place it can be traced back to.

The site: eight Tesla V4 stalls in PG&E territory on the BEV-2 rate, retail price $0.45 per kWh, Standard ramp, 20% down on a ten-year loan at 8%. Every default is the one documented on the methodology page; none has been adjusted.

Capex and the cheque at closing#

The utility upgrade line is zero in the default; a real site enters its interconnect quote here. The build-cost post covers where the hardware and install figures come from.

The running costs#

Electricity and the network fee rise with volume. Rent escalates. The property tax falls as the assessed base depreciates. Everything else is flat.

Twelve months of the ramp year#

Utilization follows the Standard curve, from 100 kWh per stall per day in a fifteen-day opening month to 260 in December. Net operating cash is revenue less every line above, including the loan payment.

Month one carries the $46,875 of sales tax. Months three, six, nine and twelve receive the quarterly LCFS cash: $3,856, $8,017, $9,143 and $9,462, one quarter in arrears and net of the aggregator's 15% commission. The year ends with $609,600 kWh dispensed, $274,320 of charging revenue, $30,478 of net LCFS credit, and a cumulative position of −$158,515, which is the peak cash deficit on the capex table above.

Fifteen years#

From year two the month-twelve level grows 5% a year to year seven and 3% after that; retail price escalates 5% a year; electricity escalates 5%; rent 3%. LCFS credits run for nine years. The loan ends after year ten.

Three features of the table explain most of what the headline numbers say.

The site turns operationally positive in year nine, slips back in year ten when the LCFS line ends, and then steps up by $159,000 in year eleven when the loan does. The cumulative hole is at its deepest, $556,572, in the last year of the loan, not the first year of the site.

Revenue grows faster than electricity: 3.5× over the horizon against 3.2×, because price escalates on the whole volume while the fixed demand line does not escalate with throughput at all. The margin per kWh widens slowly over fifteen years.

Cumulative cash crosses zero in year fourteen. That is the 171-month payback.

Assembling the headline#

The tax shield is the federal marginal rate applied to the full depreciable basis in year one, since bonus depreciation is at 100% in the default; whether an owner can use it depends on their own return, which the tax-stack post discusses. The terminal value is a sale assumption at the end of the horizon, and the payback-vs-NPV-vs-IRR post explains why an IRR of 8.7% and a multiple of 3.98× can describe the same site. The engine's reverse solve reports the two things that would change the verdict: a retail price of $0.579 instead of $0.45, or year-two utilization of 281 kWh per stall per day instead of 227.

That is the whole default scenario. Every other post on this blog that quotes "the default site" is quoting a row from one of these tables, and the scenario wizard produces the same tables for any address, tariff and set of inputs.

Engine outputs are model projections under the stated assumptions, not advice or guarantees. All defaults are documented on the methodology page and are the engine's shipped values as of this post's date.