Key Takeaways

  • Shared solar (community solar) programs can put enrollment or program-size limits in place; that can freeze new subscriptions or change crediting rules.
  • If you own an EV or home battery, subscribe only for the portion of generation you can reliably use: example math helps avoid wasted credits.
  • Practical actions—check contract terms, size subscriptions to match 1–3 months of EV charging, and combine time-of-use rates with batteries—can save $100s per year.

What You Need to Know

Shared solar lets multiple customers subscribe to a single solar array and receive on-bill credits. Utilities or regulators may impose caps that limit how much capacity or how many subscribers a program can have; when a cap is reached, programs often close to new subscribers or change the crediting method.

Key contract and program items to check: subscription fee ($5–$40/month is common), contract length (1–20 years typical; some offer 20+ year terms), credit rate (often expressed in ¢/kWh relative to retail), and portability (can you move the subscription if you move?). For example calculations, use a U.S. residential electricity price of $0.16/kWh as a baseline: charging a 60-mile-range EV with a 60 kWh battery once costs roughly $9.60; a 30 kWh EV battery costs about $4.80 per full charge.

Caps matter because they change availability and economics. If a program closes due to a cap, you may lose the chance to enroll at a favorable credit rate. Regulators sometimes make caps adjustable, so check your utility or state community solar portal for enrollment status and program limits.

How to Save Money

  1. Match subscription size to likely use: Estimate your monthly kWh from regular loads plus EV charging. Example: a household using 800 kWh/month plus an EV adding 300 kWh/month should seek ~1,100 kWh/month in credits or scale subscription to offset the bill portion you want relieved. Avoid over-subscribing because excess credits might be limited or paid out at a low avoided-cost rate.

  2. Use batteries to capture credits during low-use periods: If your shared-solar credits arrive when you don’t consume (midday), a home battery (10 kWh usable size typical) can store 8–10 kWh to shift to peak hours. At $0.16/kWh, discharging 10 kWh during peak saves about $1.60 that day; over a year that can add up to $150–$400 depending on rate structure and cycling frequency.

  3. Coordinate EV charging with solar production: A Level 2 charger (around 7.2 kW) can fully charge a 30–60 kWh EV battery in 4–8 hours. Set charging from 10:00 to 18:00 when shared solar production is highest to maximize on-site use of credits and reduce reliance on exported credits that might be lower value.

  4. Watch program caps and enrollment windows: If a program is near its cap, expect enrollment to close or contract terms to become less favorable. Get on waitlists, but avoid rushed decisions: compare credit rates, monthly fees, and exit penalties before signing.

  5. Check portability and contract length: If you plan to move within the next 3–5 years, prefer shorter terms or portable subscriptions; otherwise a 10–20 year fixed subscription can lock in predictable savings.

Bottom Line

Shared solar caps can change who can join and how credits are valued, which directly affects subscribers, EV owners and battery users. Practical moves—size subscriptions to real energy needs, align EV charging with solar production, add a battery only if it improves credit utilization, and scrutinize fees and contract length—help maximize savings. Because program rules and caps vary by state and utility, confirm current enrollment status and crediting details with your local community solar administrator before you commit.