We have bragged on the value of the SaaS product that we use for producing solar proposals, Energy Toolbase, many times before in this Newsletter. One of the more interesting things that it is able to tell you is the percentage of energy that is exported to the grid. Indeed, in many instances, 50% or more of the energy produced by the PV system is not consumed locally; rather, it is sent back to the grid where the system owner receives a credit for that energy.
This is all fine and good in a pure net-metering environment combined with a tiered (or flat) utility rate structure. But such conditions are vanishing rapidly in many areas, and are already a thing of the past in SCE territory where Time-of-Use (TOU) rates and Non-Bypassable Charges erode the value of net metering, and increase the value of local consumption.
Which is where Electric Vehicles (EVs) come in, since they create an expanded demand for local electrical energy consumption. Combined with a small amount of storage - to make that energy available at the convenience of the system owner - and one recent study has found that payback periods for the solar system can be reduced dramatically. The study, which focused on Great Britain and Germany - countries with far less solar insolation than sunny SoCal - determined that:
[I]n Britain – where it currently takes an astounding 19 years to pay off rooftop solar – the payback for a “typical” 4kW rooftop PV system when combined with an 8kWh battery and a small 35kWh EV could be slashed to four years by 2025, and one year in 2030.
Of course, your mileage may vary. But as new product offerings like the Enphase Ensemble system come on line (and inevitably become cheaper), this will become a more and more standard offering. Ten years from now, when EVs are everywhere and TOU rates are not only standard, but ever more draconian, the economics of these combined systems will truly be a "no brainer."
We are eagerly looking forward to that day.