Solar + EV integration
Splitting charging between work and home changes the math meaningfully. Add your driving, home solar offset, and workplace details to see the real annual cost difference.
How it works
Step 1
Check with HR or facilities to confirm whether charging is free, subsidized, or paid, and at what rate.
Step 2
Consider station availability, your parking situation, and how often you're actually at the workplace on a typical week.
Step 3
Size your home solar system to cover your full charging need independently, with workplace charging as additional savings on top.
When an employer offers genuinely free workplace EV charging, it's almost always the lowest-cost charging option compared to any home charging arrangement, including solar-offset charging, since there's simply no cost at all for that portion of energy. Even a modest share of daily charging shifted to a free workplace station can meaningfully reduce annual charging costs.
Not all workplace charging is free, and some employers charge a rate that may be higher, lower, or comparable to a home solar-offset rate. In these cases it's worth comparing the actual workplace rate against your home blended rate, referencing current EIA electricity data, rather than assuming workplace charging automatically saves money, since a poorly priced workplace station could actually cost more than charging at home with solar.
If a reliable share of charging happens at work, less energy needs to come from home solar, which could mean a smaller home system, per the system size by monthly kWh usage tool, adequately covers your remaining need. This is worth factoring into sizing conversations with an installer if workplace charging access is well-established and expected to continue, though it's generally wiser to size for full independence and treat workplace charging as a bonus rather than a dependency.
Employer benefits, parking situations, job changes, and charging station availability can all shift over time in ways outside your control, so relying heavily on workplace charging in your core financial planning carries some risk. Sizing your home system to independently cover your full charging need, with workplace charging layered on top as additional savings, provides a more resilient long-term plan.
If workplace charging meaningfully reduces your home charging need, check the solar array oversize calculator to see how that affects your ideal home system size, keeping in mind the resilience considerations above. The community and shared solar hub fills in the rest of that picture.
Questions
For 30 miles of daily driving with 80% home solar offset, splitting charging 50/50 with free workplace charging cuts annual cost roughly in half, from about $243 to $121 a year. The savings scale directly with how much of your total charging the workplace station actually covers.
Not necessarily. Free workplace charging is typically cheaper than any home charging option, but subsidized or paid workplace charging might cost more or less than solar-offset home charging depending on the specific workplace rate. Compare the actual workplace rate against your home solar blended rate rather than assuming workplace charging automatically wins.
Yes, if a meaningful share of charging happens at work, less energy needs to come from home solar, which could mean a smaller home system is sufficient. This is worth factoring into sizing decisions if workplace charging access is reliable and expected to continue long-term.
It's worth treating workplace charging as a bonus rather than a guaranteed permanent arrangement when making long-term sizing decisions, since employer benefits and charging station availability can change. Sizing your home system to cover your full charging need independently provides a more resilient baseline, with workplace charging as additional savings on top.
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