Battery Storage, Dynamic Rates, and Solar Power: What the 2026 Research Findings Reveal for Direct Investors
Two independent studies will provide the first empirical evidence in 2025/2026 of the combined effects of battery storage, dynamic rates, and photovoltaics: a reduction in electricity costs behind the meter ranging from 12.7 to over 80 percent. For direct investors, the dynamic tariff is thus shifting from an optional consideration to a mandatory part of every due diligence process—as a cash flow stabilizer and a safeguard against changes in the market regime starting in 2027.
The short answer
The combination of battery storage, a dynamic electricity rate, and a photovoltaic system demonstrably reduces electricity costs behind the meter—by 12.7 to over 80 percent, depending on the amount of load that can be shifted. For direct investors, the dynamic rate is not a business model in its own right, but rather a cash flow stabilizer: It makes the anchor customer more cost-effective and ensures the system is ready for connection starting in 2027.
This article is intended for direct investors in photovoltaic systems with equity capital of at least 100,000 euros and a system lifespan of 20 to 40 years. It explains how the combination of battery storage and dynamic electricity rates affects cash flow stability and system valuation—and which regulatory requirements will make this model a standard practice rather than an optional one by 2026.
1. What Scientific Studies in 2025/2026 Will Prove for Direct Investors
Dynamic electricity rates link the price of electricity to spot market prices on an hourly or quarter-hourly basis. Until the end of 2025, their economic impact in conjunction with photovoltaics was largely based on model calculations. Two independent studies from the fourth quarter of 2025 provide empirical evidence for the first time—thereby shifting the discussion from forecasting to a robust data foundation for investment analysis.
1.1 The Lorenz Study: 448 households, five years of smart meter data
A team from the universities of Bamberg, Würzburg, Zurich, and Chemnitz analyzed smart meter data from 448 German households over a five-year period (2019 to 2023). Key finding: A household with a photovoltaic system, a 10-kWh storage unit, and a day-ahead rate pays an average of 12.7 percent less for the remaining electricity from the grid than it would with a fixed-price plan—simply by strategically shifting its self-consumption, without actively responding to price signals.
If the storage control system also actively responds to day-ahead prices, up to six percentage points are added. In the theoretical optimal scenario with perfect price forecasting, an additional benefit of up to 14 percent is possible. Important to note: The model does not make solar power itself any cheaper—what decreases is the price of the remaining electricity that the household draws from the grid. The researchers based their calculations on BDEW fixed prices, a feed-in tariff of 8.1 cents per kilowatt-hour, and hourly EPEX spot prices.
1.2 The Neon/Naturstrom Study: Heat Pumps and Electric Cars
A second study by Neon Neue Energieökonomik, commissioned by naturstrom AG, simulated how heat pumps and electric cars would perform under a dynamic rate structure from September 2024 through August 2025. While the Lorenz study focuses on the typical household, Neon’s analysis includes large-scale consumers with flexible usage patterns. The range extends from about 6 percent for a heat pump alone to 82 percent for an electric vehicle in combination with time-varying grid fees pursuant to Section 14a of the German Energy Economy Act (EnWG).
One finding from both studies is particularly relevant for investors: A home storage system without a solar power system is hardly cost-effective even under a dynamic rate structure—at best, it results in a cost reduction of about 8 percent after deducting the investment. The economic benefit only materializes when the system is combined with a solar power system. The dynamic electricity rate is therefore not a standalone business model, but rather a multiplier for an already functioning direct investment.
| Use case | Cost savings vs. fixed price | Study |
|---|---|---|
| Solar PV system + 10-kWh storage unit, without active optimization | −12,7 % | Lorenz et al. 2025 |
| Solar PV system + 10-kWh storage unit, with day-ahead optimization | up to an additional +6% | Lorenz et al. 2025 |
| Heat Pump, Intelligently Controlled | about −6% | Neon / Naturstrom 2025 |
| Heat Pump + Time-Varying Grid Fees (Section 14a of the Energy Industry Act (EnWG)) | up to 28% off | Neon / Naturstrom 2025 |
| Electric car, smart charging control | about −30% (avg.) | Neon / Naturstrom 2025 |
| Electric Cars + Time-Varying Grid Fees (Section 14a of the Energy Industry Act (EnWG)) | up to 82% off | Neon / Naturstrom 2025 |
| Residential Storage Solo (without PV), Net After Investment | about −8% | Neon / Naturstrom 2025 |
| Sources: pv magazine, November 24, 2025, on the Lorenz study; Neon brief study for naturstrom AG, October 2025; naturstrom AG press release, October 27, 2025. As of August 2026. | ||
2. Why the dynamic electricity rate beats the fixed rate: three factors
2.1 Effect 1 — Optimization of Self-Consumption
A solar power system generates the most electricity around noon—precisely when solar generation (and, during windy periods, wind generation as well) is high and prices on the electricity exchange are at their lowest on an annual average. In 2025, German day-ahead prices fell below zero for 573 hours (plus 81 hours with a zero price), setting a new record; these hours are concentrated in the sunny spring and summer months, when supply exceeds demand. A storage system shifts additional kilowatt-hours from this low-cost period into the evening, when the dynamic tariff is typically well below the fixed-price level. This spread between midday and evening is the real driver of the calculation.
2.2 Effect 2 — Avoiding Peak Loads
For just a few hours each year—especially on dark, windless winter evenings—market prices rise well above the fixed rate. Electricity price fluctuations are significantly greater in winter than in summer because, when solar and wind generation is low, demand drives up the price. It is precisely during these hours that electricity demand is at its highest anyway. A property with a storage system and solar array largely bridges these expensive periods using energy from the storage system; the fixed-price customer pays for them proportionally as part of their flat rate. Over the course of the year, these peak-load hours account for only a small portion of consumption, but they have a disproportionately large impact on the fixed price.
2.3 Effect 3 — Movable Loads
As soon as a heat pump or electric car is installed in a property, the savings potential multiplies. A heat pump that schedules its operation during the cheapest hours can save up to 28 percent with time-of-use grid rates. An electric car that waits for the next low-price hour reduces its charging costs by an average of 30 percent—and up to 82 percent under Section 14a of the Energy Economy Act (EnWG). The key finding of the studies is therefore not the individual figure, but the interplay: shiftable load makes consumption a controllable variable.
Any direct investor who invests in a new photovoltaic system in 2026 would be wise to link the revenue side (direct sales, market value of solar power) with the consumption side at the same property—thereby taking advantage of both halves of the same price curve. We describe the revenue effects on the electricity market in our analysis of negative electricity exchange prices and PV investments; here, we focus on their counterpart on the consumption side.
3. What the study figures actually mean in terms of direct investment
Direct investors do not profit directly from the dynamic tariff—their main sources of revenue are EEG feed-in tariffs and direct sales, which we cover in the Guide to PV Storage Investments and the 2026 EEG Feed-in Tariff Guide. The tariff has an effect one level down: on consumers behind the meter.
3.1 Consequence 1 — More Stable Core Customers
A direct investment whose returns are partly based on self-consumption or tenant electricity supplied to a commercial or residential end-user becomes more economically viable when these electricity customers can cover their remaining electricity needs at a low cost. If the dynamic rate reduces the price of the remaining electricity by 10 to 15 percent, the risk that the end-user will later seek to renegotiate the model decreases. Particularly in tenant-electricity arrangements, where the plant operator also serves as the energy supplier for its tenants, affordable residual electricity procurement fosters acceptance. Stable anchor customers mean stable cash flows—which is key to preserving value over a 20-year term.
3.2 Consequence 2 — Interoperability for the Period After 2027
The planned CfD requirement for new installations (contracts effective July 17, 2027) caps the potential for market value gains on the revenue side while simultaneously reducing market value risk. Precisely because the potential on the revenue side is diminishing, every lever on the consumption side becomes more important. Variable rates are part of this. Our article on the CfD requirement for PV investors explains how the regulatory framework is changing.
3.3 Consequence 3 — Smart meter requirement already met
For photovoltaic systems of 7 kilowatts or more, the smart metering system has been mandatory since the Solar Peak Act took effect—and it is precisely this metering system, including the smart meter gateway, that is the basic requirement for hourly billing under a dynamic rate plan. A PV system of 7 kilowatts or more that goes into operation in 2026 is therefore already technically equipped for this model. For more details, see our overview of the 2026 smart meter mandate.
| Consumption type | Residual Electricity Fixed Rate | Dynamic residual current | Estimated annual savings |
|---|---|---|---|
| Commercial customers without flexible load (40,000 kWh/year) | 28 cents per kWh | 25 cents per kWh | about 1,200 € |
| Commercial building with a heat pump (60,000 kWh/year) | 28 cents per kWh | 22 cents per kWh | about 3,600 € |
| Commercial property with a wallbox charging station (80,000 kWh/year) | 28 cents per kWh | 17 cents per kWh | about 8,800 € |
| Methodology: Indicative ranges based on the Neon study (October 2025) and the HTW Berlin Energy Storage Survey 2026, applied to commercial consumption profiles. This is not a statement regarding returns or guarantees, but rather guidance on stabilizing anchor customer cash flow. As of August 2026. | |||
4. Section 41a of the Energy Industry Act (EnWG) and the Provider Obligation: Status as of 2026
As of January 1, 2025, Section 41a of the Energy Industry Act (EnWG) requires every electricity provider to offer at least one dynamic rate plan in its portfolio. These new rules have shifted the landscape: The savings outlined in the studies are no longer a question of whether such an offer exists, but rather which energy provider offers it and under what terms. Availability is guaranteed by law; however, the quality of the terms varies significantly across the market.
4.1 Market Overview of Specialty Providers in Early 2026
By early 2026, a market comprising about a dozen specialized providers had established itself—including Tibber (which reports having around 400,000 customers in Germany), aWATTar, Rabot Charge, Octopus Energy, Ostrom, 1KOMMA5°, Voltego, Lichtblick, naturstrom smart, and Enpal. Alongside these are the mandatory offerings from basic providers and municipal utilities, which typically fall short in terms of the quality of their terms and conditions. Those who have a choice should pay attention not only to the spot market surcharge but also to the quality of the app: hourly price views, forecasts, and push notifications are often more important in everyday life than the last 0.2 cents in surcharge.
4.2 Smart Meter Rollout: Reality and the Law
Hourly billing requires a smart metering system as defined by the Metering Point Operations Act; a traditional meter or a modern metering device without a smart meter gateway is not sufficient. For the fourth quarter of 2025, the Federal Network Agency reports approximately 3.1 million smart metering systems installed at approximately 56.5 million metering locations—a total penetration rate of 5.5 percent. For cases subject to mandatory installation under the law (annual consumption of 6,000 to 100,000 kWh, PV systems of 7 kW or more, and controllable consumption devices pursuant to Section 14a of the Energy Industry Act), the rate stands at 23.3 percent; this exceeds the statutory interim target of 20 percent set for the end of 2025.
For direct investors, this means that the installation of a smart meter is mandatory for any new system with a capacity of 7 kW or more. Anyone who wishes to sign up for the rate plan later will have already met the technical requirements. The question is no longer whether a dynamic rate plan is technically feasible, but rather when the metering point operator will carry out the installation. Since 2025, customers have been entitled to installation within four months upon voluntary request. The regulatory gap between the metering system requirement and the provider’s obligation has been closed since 2025; the only remaining open question for 2026 is the rollout speed.
5. The Environmental Dividend: Curtailment as an ESG Argument
Direct investors with an ESG mandate have had an additional, verifiable argument since 2025. The energy transition’s power system produces surpluses precisely when they are least needed—and that’s exactly where storage and flexible electricity use come into play.
5.1 Curtailment Data for 2024
The Federal Network Agency reports PV curtailment of 1,389 gigawatt-hours for 2024—a 97 percent increase compared to 2023 and the largest jump among all renewable energy sectors; Bavaria alone accounted for 986 gigawatt-hours. This was due to new installations and high solar radiation in the summer of 2024. For 2025, the Federal Network Agency expects another increase in light of continued expansion. The combination of a photovoltaic system, storage, and a dynamic tariff is the direct technical solution: The Neon study demonstrates that an intelligently charged electric vehicle can draw up to 42 percent of its electricity from hours that would otherwise have been subject to curtailment.
5.2 CO2 Impact per Kilowatt-Hour Shifted
The impact can be quantified for ESG reporting. With an emissions factor on the order of that of the German electricity mix (approximately 350 grams of CO2 per kilowatt-hour, according to the Federal Environment Agency), every kilowatt-hour replaced by storage and control during a high-emissions hour avoids approximately 0.35 kilograms of CO2. Over a 20-year plant lifespan, this adds up to a measurable reduction in emissions that can be documented in any investor presentation—and can even be continuously verified using mandatory smart meter data.
6. Practical Application: How a Dynamic Electricity Rate Is Technically Integrated
A smart meter and an energy management system are essential for optimally combining a battery storage system with dynamic pricing and a solar power system. In this architecture, the battery storage system acts as a smart buffer between the home electrical system, the solar power system, and the public grid. Implementation takes place across three layers, which are planned separately: metering system, control system, and contract.
6.1 Layer 1 — Intelligent Measurement System
A smart meter is a digital electricity meter that automatically collects consumption data and transmits it at short intervals to metering point operators, grid operators, and electricity providers. It is required by law for dynamic rates, as this is the only way to enable hourly billing. The primary metering point operator supplies the smart meter in accordance with the specifications of the Federal Office for Information Security; for systems rated at 7 kW or higher, installation is mandatory and must be included in the connection application. The meter records active power consumption every 15 minutes—these values form the basis for billing under any dynamic rate plan. Without them, the provider falls back on standard load profiles, and the advantage of the model is lost.
6.2 Layer 2 — Energy Management System (EMS)
An energy management system (EMS) automatically controls electricity procurement and consumption: It optimally aligns battery storage, photovoltaic systems, and flexible loads—such as heat pumps or wallboxes—with the price signals of the dynamic rate plan. Specifically, it activates individual devices selectively during hours when market prices are low and scales them back during high-price hours; it automatically determines when to charge, store, and procure electricity. For commercial investments, open platforms are recommended that allow for a change of provider without replacing hardware and integrate devices via standard interfaces such as EEBus or Modbus.
6.3 Tier 3 — Electricity Contract
The contract is signed last—ideally only once the metering system and control system are operating reliably. The choice among specialized providers is primarily a matter of markup margins, base fees, app quality, and additional services such as load management and forecast accuracy. The sequence is crucial: Because Layers 1 and 2 function independently of the provider, a later switch remains possible at any time without having to replace hardware. A properly set up property thus remains competitive, even as the provider market continues to consolidate.
7. Storage System Design: Cycle Life, Grid Charging Capability, and Sizing
7.1 The battery must be capable of being charged from the mains
To take advantage of the price difference between cheap and expensive hours, the battery must be able to actively recharge from the public grid—not every system allows for this. Charging takes place using low-cost electricity from the power exchange or from the home’s own generation when the sun is shining; during periods of high prices, the battery releases the energy. Without the ability to charge from the grid, the benefit is limited to simply shifting self-consumption, and part of the effect from procuring electricity on the spot market is lost.
7.2 Offset the price difference against losses and wear and tear
Every charging cycle results in conversion losses; in practice, approximately 85 to 90 percent of the charged energy is usable. Additionally, charging from the grid increases the number of charging cycles per year and thus the rate of wear and tear. Additional revenue is generated only if the price difference between off-peak and peak hours is large enough to exceed charging losses and battery degradation. This calculation is an essential part of any serious economic analysis—operational experience shows that overly optimistic assumptions overstate the effect.
7.3 Aligning Capacity with Flexible Demand
A storage system that is too small cannot fully take advantage of short-term price windows; one that is too large incurs acquisition costs that are not recouped over the system’s lifecycle. The optimal capacity depends on the property’s flexible electricity consumption—heat pump, wallbox, and controllable large appliances. In all cases, controllability via the energy management system remains crucial: without intelligent control at 15-minute intervals, the savings potential cannot be realized.
8. Three Arguments for Investment Due Diligence 2026
- Stabilized risk profile. A photovoltaic system connected to an end user carries a renegotiation risk: If electricity becomes too expensive over the long term, the question of adjusting the terms arises. A dynamic tariff structurally alleviates this pressure and reduces price volatility for the end consumer. Potential drawbacks, such as price fluctuations, are quantified in the data and are largely mitigated by the storage component. The tariff thus stabilizes cash flow over the term of the agreement.
- Grid Connection Compatibility for 2027 and Beyond. With the mandatory CfD requirement taking effect in 2027, the balance between revenue and procurement costs will shift. Variable concepts will then no longer be optional but rather the key to achieving the documented 12 to 28 percent reduction in procurement costs. A plant built in 2026 that has incorporated the technical setup into its design will already be ready for connection under the market regime starting in 2027—without the need for retrofitting.
- An ESG narrative with measurable impact. The amount of CO2 avoided per year of operation is not a marketing claim, but a quantifiable metric that can be documented in every annual report—and is continuously verifiable through mandatory smart meter data. For institutional investors with ESG mandates, this is precisely the level of data quality that is increasingly in demand today.
Are you planning a direct investment that includes a self-consumption or storage component?
Logic Energy plans, finances, and manages photovoltaic systems—from site selection through permitting and inverter selection to smart meter connection—all under one roof. The contractual partner for direct investments is mediplan Helm e.K., a partnership with personal liability of the owners. Talk to us about your specific investment opportunity.
9. Conclusion
A study conducted in Bamberg, Würzburg, Zurich, and Chemnitz in 2025 provided the first empirical evidence for what had previously been a model assumption: A 10-kWh storage system combined with a photovoltaic system and a dynamic rate reduces residual electricity costs by an average of 12.7 percent. A second study by naturstrom and Neon shows that the effect extends to as much as 28 percent for heat pumps and 82 percent for electric cars. With the provider obligation under Section 41a of the Energy Economy Act (EnWG), the model has been available nationwide since 2025; and with the smart meter requirement for systems of 7 kW or more, every new PV system is technically equipped for it anyway.
For direct investors, the implication is clear: Variable rates will no longer be an option in 2026, but rather a standard part of any serious due diligence process—as a cash flow stabilizer, as a safety net for the market conditions starting in 2027, and as an ESG data point with a measurable impact. Logic Energy designs photovoltaic systems in which these components are factored in from the very beginning. mediplan Helm e.K. signs every investment agreement with personal owner liability.
Frequently Asked Questions
What does a dynamic electricity rate mean for my direct investment in solar power?
It reduces the residual electricity costs for consumers downstream of the meter, thereby stabilizing the system’s cash flow. It has no direct impact on the system’s return on investment—which comes from EEG feed-in tariffs or direct sales. Its value lies in providing a more stable base of customers and ensuring compatibility with the market regime starting in 2027.
Which studies support these cost savings?
Two independent studies from the fourth quarter of 2025: the Lorenz study conducted by the Universities of Bamberg, Würzburg, Zurich, and Chemnitz (448 households, five years of smart meter data, 12.7 percent) and the Neon study commissioned by naturstrom AG (heat pumps up to 28 percent, electric cars up to 82 percent). Both are publicly available.
Do I need a smart meter for a dynamic rate plan?
Yes. Hourly billing requires an intelligent metering system with a smart meter gateway; a traditional meter or a modern metering device is not sufficient. For photovoltaic systems of 7 kilowatts or more, installation has been mandatory under the Solar Peak Act anyway and must be included in the grid connection contract.
Which providers will be operating in Germany in 2026?
As of early 2026, there are about a dozen specialized providers, including Tibber, aWATTar, Rabot Charge, Octopus Energy, Ostrom, 1KOMMA5°, Voltego, Lichtblick, naturstrom smart, and Enpal. In addition, since the enactment of Section 41a of the Energy Industry Act (EnWG), every basic provider has been required to offer a mandatory plan, though the terms of these plans are generally less favorable.
Is a battery storage system worth it without a solar power system when you have a dynamic rate plan?
Hardly. The Neon study shows that, at best, a home storage system without a solar PV system results in a cost reduction of about 8 percent after the investment has been recouped—too little to pay for the storage system through spot market use alone. The economic benefit only materializes when the system is used in conjunction with a solar PV system.
What role does Section 14a of the Energy Industry Act play in terms of economic viability?
Section 14a of the Energy Industry Act (EnWG) allows for time-of-use grid fees for controllable consumption devices such as heat pumps and wallboxes. It significantly increases the savings: for heat pumps, from about 6 percent to up to 28 percent; for electric cars, from about 30 percent to up to 82 percent. For properties with controllable large-scale consumers, it is the key additional lever.
Is a dynamic rate plan part of the standard configuration of a Logic Energy system?
Yes. Logic Energy designs photovoltaic systems so that the metering system, energy management, and connection allow for the dynamic rate from the very beginning. The rate agreement itself remains the responsibility of the end consumer; however, the technical requirements are already in place for any system with a capacity of 7 kilowatts or more.
What are the disadvantages of a dynamic rate for investors?
The main drawback is price volatility: During rare peak-load hours, the spot price exceeds the fixed price. It is precisely these hours that the storage component largely offsets. Without storage and without shiftable loads, the benefit is minimal—the effect is only realized through flexible consumers within the facility.
References
- pv magazine — Battery Storage and Dynamic Rates: Study Shows Clear Financial Benefit, Nov. 24, 2025
- Neon New Energy Economics — Brief Study on Dynamic Electricity Rates for naturstrom AG (Full-Text PDF), October 2025
- naturstrom AG — Up to 82 Percent: Study Shows Savings Potential of Dynamic Electricity Rates (Press Release), Oct. 27, 2025
- pv magazine — Study Identifies High Savings Potential Through Dynamic Electricity Rates and Time-Varying Grid Fees, Oct. 27, 2025
- Section 41a of the Energy Industry Act (EnWG) on gesetze-im-internet.de — Requirement to Offer Dynamic Electricity Rates, as of 2026
- Federal Network Agency — Rollout of Smart Metering Systems, Q4 2025 Analysis (23.3% mandatory installation rate, approximately 3.1 million smart metering systems), as of March 27, 2026
- CHP Information Center — Negative Electricity Prices in 2025: 573 hours of negative prices, a new record, March 11, 2026
- pv magazine International — PV curtailment jumps 97% in Germany in 2024 (BNetzA data), April 3, 2025
- HTW Berlin — Energy Storage Inspection 2026, 2026
- German Solar Industry Association (BSW-Solar) — Battery Storage Capacity to Increase Fivefold Within Five Years, January 12, 2026
Edited by Logic Energy. Last updated: August 2026.
