Your Neighborhood Solar Panels Could Charge Your Car at Half the Price — If the Rules Allow It

In Switzerland today, two energy revolutions are happening on the same street corner — and completely ignoring each other. Rooftop solar panels generate more electricity than local residents can use. A few meters away, electric vehicle drivers plug into public chargers and pay among the highest per-kilowatt-hour prices in Europe. The surplus solar gets sold back to the grid for 0.06 Swiss francs per kilowatt-hour. The EV drivers pay 0.57. That's nearly a tenfold gap — and it exists not because the physics are complicated, but because the institutions haven't caught up.

A new paper by Li, Liu, Orfanoudakis, Okur, Panda, Vergara, and Koirala (2026) proposes a deceptively simple fix: let the neighborhood solar community become the EV charger. Their concept, called Community-to-Vehicle (C2V), is less a technological innovation than an institutional one. It requires no bidirectional batteries, no wholesale market participation, no complex grid hardware. It requires a pricing rule and a regulatory handshake — and Switzerland's own new electricity law, which came into force on 1 January 2026, already provides the framework to make it legal.

The Science

The study is built around a real building: NEST, a research and innovation facility at the Empa campus in Dübendorf, outside Zurich. NEST hosts a mixed community of residential renters and office workers, along with 36 kilowatts-peak of rooftop solar panels — enough to generate about 22,238 kilowatt-hours of electricity per year, against a community annual demand of 44,075 kWh. Three households in the community own PV systems; four do not.

This real-world dataset is combined with measured EV charging profiles drawn from approximately 18,000 public charging points across Switzerland, logged between 2022 and 2025. The researchers filtered these to the Zurich region in 2025, focusing on 11 kW AC chargers — the standard public charging speed for most EVs today — to produce 20 representative charging profiles that reflect actual driver behavior rather than idealized assumptions.

The modeling framework runs hourly simulations over a full representative year, comparing two institutional scenarios. In Scenario 1 (S1), the status quo: the local energy community operates under collective self-consumption rules, sharing solar among members at a negotiated internal price and exporting whatever's left to the grid at the feed-in tariff. EV drivers charge independently at a commercial public charger. The two systems never interact. In Scenario 2 (S2), the C2V model: the community installs two 11 kW charging points, declares itself the charging infrastructure provider, and directs surplus solar to those chargers before exporting anything to the grid. EV users pay a "community charging price" — set below the commercial rate but above the community's own cost of buying grid electricity — regardless of whether the electrons come from solar panels or the grid.

To capture the range of possible EV demand levels, the study defines three sub-scenarios — Low, Medium, and High — based on how much of the community's solar surplus is actually absorbed by EV charging. This is an important design choice: it acknowledges that real-world EV demand is variable and tests the framework across a realistic spread of outcomes.

What They Found

The central result is striking in its clarity. Under the C2V framework, the share of locally generated solar power absorbed within the community — rather than exported to the grid — rises from 62% in the separation scenario to 89% in the High C2V scenario (Li et al., 2026). That 27 percentage point gain is achieved entirely by redirecting surplus that would otherwise leave the community at rock-bottom prices.

Local PV Absorption Rate by Scenario

Label	Value
S1 (Separation)	62 %
C2V – Low	62 %
C2V – Medium	75 %
C2V – High	89 %

Source: Li et al. (2026). Low/Medium/High refer to EV surplus utilization levels.

To understand why this matters, consider the price ladder at the heart of the paper. The researchers formalize it as:

$${\lambda }^{\text{sell}}<{\lambda }^{\text{loc}}<{\lambda }^{\text{buy}}<{\lambda }^{\text{EV}}<{\lambda }^{\text{public}}$$

Starting from the left: electricity exported to the grid fetches just 0.06 CHF/kWh (the feed-in tariff, \lambda^{\text{sell}}$). The internal community sharing price, $\lambda^{\text{loc}}, sits at 0.10 CHF/kWh — already a 67% improvement for solar households compared to exporting. The community's cost of buying grid electricity, ${\lambda }^{\text{buy}}$, is 0.241 CHF/kWh. The proposed community EV charging price, ${\lambda }^{\text{EV}}$, is swept between 0.30 and 0.55 CHF/kWh in the analysis. And commercial public charging costs 0.57 CHF/kWh. Every link in this chain represents a value that currently evaporates between institutional boundaries. C2V captures it.

For the households with solar panels, the benefit is direct and democratic. When surplus solar is routed to EV chargers rather than to the grid, PV-owning households receive the internal sharing price (0.10 CHF/kWh) rather than the feed-in tariff (0.06 CHF/kWh) for that energy. The gain is modest per kilowatt-hour, but it accumulates meaningfully over a year — and, crucially, it is distributed proportionally among all solar households regardless of how large their installation is. The percentage revenue increase is nearly identical across the three PV-owning households in every scenario (Li et al., 2026). C2V doesn't just raise incomes for solar households; it raises them equitably.

Electricity Price Ladder: From Feed-in to Public Charging

Label	Value
Feed-in tariff (λ_sell)	0.06 CHF/kWh
Local sharing price (λ_loc)	0.1 CHF/kWh
Grid retail tariff (λ_buy)	0.241 CHF/kWh
Community EV price (λ_EV, mid)	0.4 CHF/kWh
Public charging price (λ_public)	0.57 CHF/kWh

Source: Li et al. (2026), EKZ (2025), MOVE (2025). Community EV price shown at midpoint of swept range (0.40 CHF/kWh).

For EV drivers, the math is even more compelling. At a community charging price of 0.40 CHF/kWh — a reasonable midpoint in the study's sweep — drivers pay 30% less than at a commercial charger. At 0.30 CHF/kWh, that gap widens to nearly 47%. Under the High scenario, this translates to aggregate annual savings worth thousands of francs across the EV user pool, depending on charging volume.

For the community itself, the infrastructure economics look surprisingly favorable. Two 11 kW AC chargers cost roughly 6,000 CHF to install. According to the study's revenue model, a community charging price of 0.40 CHF/kWh generates annual infrastructure revenue sufficient to recover that investment within a few years — and potentially within a single year under the High charging scenario. The revenue comes from two sources: the premium earned when surplus solar (bought from prosumers at 0.10 CHF/kWh) is sold to EV drivers at the community rate, and a smaller margin earned when grid electricity is passed through to chargers at the same community rate.

EV Charging Supply Mix by C2V Scenario

Label	Value
C2V – Low	1 MWh
C2V – Medium	3 MWh
C2V – High	6 MWh

Source: Li et al. (2026). High scenario absorbs up to ~6 MWh of surplus PV annually.

There is one complication worth taking seriously. Peak electricity import — the maximum power the community draws from the grid in any given hour — rises by approximately 20 kW when the C2V chargers are operating at full capacity. That takes the community's peak import from around 10.8 kW to 30–32 kW, roughly matching the combined rated power of both chargers. This may require an upgrade to the community's grid connection before C2V deployment. The researchers are careful to note, though, that peak export does not worsen: because the annual surplus peak doesn't coincide with the times EV users are present in the study's charging profiles, C2V doesn't make reverse power flows into the grid any worse (Li et al., 2026). The grid concern is real but bounded — predictable and plannable, not an operational risk.

Why This Changes Things

The deeper significance of this paper isn't in the numbers, impressive as they are. It's in the diagnosis of why this value gap exists in the first place — and how rarely that diagnosis gets made clearly.

Energy communities and EV charging infrastructure occupy the same physical streets, often the same distribution network substations. But they live in different regulatory worlds. Charging Point Operators (CPOs) buy electricity at retail rates, add margin, and sell to drivers. Energy communities manage collective solar assets under self-consumption agreements. Neither framework was designed with the other in mind, so the surplus solar and the EV demand simply talk past each other — like two people in the same room speaking different languages.

C2V is, at its core, a translator. By making the energy community itself the charging infrastructure provider, it collapses two separate institutional structures into one. The settlement rules for existing community members don't need to change. The grid doesn't need to be rebuilt. The EV drivers don't need to become community members. They just need to be offered a price — one that happens to be better for everyone except the commercial CPO who would otherwise have served them.

This matters beyond Switzerland. Germany, the Netherlands, Italy, and the UK have all introduced some form of collective self-consumption or energy community framework in recent years, under the European Union's Clean Energy Package. Each of these frameworks faces the same structural gap: locally generated renewable energy that can't reach local EV demand because the institutions don't touch. The C2V concept, and the price-ladder logic underlying it, is directly portable to any of those contexts.

There's also a subtler point about the design of incentives. The community charging price, ${\lambda }^{\text{EV}}$, doesn't change how much energy flows — it only determines who captures the value. Set it high, and the community recovers its infrastructure costs faster but passes less savings to EV drivers. Set it low, and drivers benefit more but the payback period stretches. This isn't a technical optimization problem with a unique solution; it's a governance decision, one that different communities with different priorities might resolve differently. The paper is admirably honest about this: "the community must decide how to split it" (Li et al., 2026).

That framing — treating the charging price as a redistribution lever rather than an efficiency variable — is a genuinely useful contribution to how we think about local energy governance. It means communities can tailor C2V to their own values: prioritize fast cost recovery to reinvest in more infrastructure, or prioritize cheap charging to attract more EV users and increase solar absorption. Both are valid. Both are achievable with the same physical hardware.

What's Next

The study is honest about its scope. The NEST case study is a single, relatively small community — seven households, 36 kWp of solar, and a clean dataset of Swiss charging behavior. Real-world deployment will encounter messier conditions: variable EV arrival times, cloudy weeks that collapse solar surplus, communities with more complex membership structures, and the organizational challenge of actually convincing a local energy community to take on the role of charging infrastructure provider.

The authors identify four clear directions for future work. First, the framework could be extended to include Vehicle-to-Community (V2C) discharge — where EV batteries send power back to the community during peak demand hours, adding flexibility in both directions. Second, the model currently treats EV availability and solar generation as deterministic inputs; incorporating stochasticity would make the analysis more robust for real deployment planning. Third, the charging price and infrastructure size (number and rating of chargers) are currently set independently; joint optimization could find better tradeoffs. Fourth, multiple communities could be aggregated to offer system-level services to grid operators — scaling C2V from a neighborhood curiosity to a meaningful grid asset.

There's also a regulatory question the paper doesn't fully resolve: who, exactly, operates the community charging infrastructure? Under Switzerland's new LEC framework, third-party participants can join an energy community, and the framework explicitly permits external users to transact with the community. But the operational and liability questions for a community that suddenly becomes a public charging provider are non-trivial. Early pilots, ideally at sites like NEST itself — a research campus already equipped with metering infrastructure and institutional appetite for experimentation — would be a natural next step.

What this paper establishes, clearly and quantitatively, is that the value is there to be captured. Somewhere between the 0.06 CHF/kWh that solar households receive for their surplus and the 0.57 CHF/kWh that EV drivers pay at public chargers, there is a spread of 0.51 CHF per kilowatt-hour that currently flows to no one. It evaporates in the gap between two regulatory frameworks that were designed independently and never told to cooperate.

C2V is a proposal to close that gap — not with new technology, but with a clearer set of rules about who can sell to whom, and at what price. In an energy transition that often reaches for technical solutions first, there's something refreshing about a paper that says: the physics already work. The challenge is institutional. And institutions, at least, can be redesigned.