The AnanaS consortium project investigated the technical feasibility and economic performance of combined solar‑thermal and combined heat and power (BHKW) systems for district heating and electricity supply. The study combined extensive data collection, load‑profile analysis, and detailed simulation of integrated plant concepts. The technical results are presented in three main areas: performance of existing BHKWs, load‑profile based forecasting, and simulation of hybrid solar‑BHKW configurations.

First, a nationwide survey of BHKWs provided measured thermal and electrical efficiencies, cost structures, and start‑up behaviour. The data revealed that continuous operation of BHKWs (so‑called “dauerläufer”) yields significantly lower heat‑generation costs than oversized units that are started and stopped frequently. However, the specific heat‑generation cost is highly sensitive to the ratio of electricity and gas prices, making the pay‑back period a key risk indicator. The CO₂ balance analysis showed that the environmental benefit of coupled generation diminishes as the share of renewable electricity increases, indicating that future BHKWs will need to incorporate biogas or hydrogen to maintain a low carbon footprint.

Second, the load‑profile analysis used standard gas consumption profiles from BDEW and temperature‑dependent clustering to identify distinct demand patterns. Correlation analysis between heat and electricity demand confirmed a strong link, enabling joint optimisation of plant operation. Forecasting models based on outdoor temperature and the identified clusters were able to predict heat demand with high accuracy, while anomaly detection highlighted rare deviations that could be addressed by flexible storage. The analysis also quantified the available roof area for solar collectors, showing that the potential collector area can be doubled compared to the VDI 3988 reference without a prohibitive increase in specific yield.

Third, a comprehensive simulation study evaluated combined solar‑BHKW systems with shared and separate storage options. The model incorporated realistic hydraulics, BHKW dynamics, and solar‑thermal performance. Results indicated that a shared storage configuration reduces the number of BHKW starts and improves overall system efficiency. Oversizing the solar collector area mitigates low solar‑coverage rates in heat‑dominated profiles; the simulation demonstrated that doubling the collector area relative to VDI 3988 remains economically viable. The study also explored the impact of varying storage volumes and BHKW regulation strategies, concluding that continuous operation with adequate storage yields the lowest heat‑generation costs, while the pay‑back period remains uncertain due to price volatility.

The project was carried out by the AnanaS consortium, comprising academic research institutions and industry partners. Over the project duration, the partners collaborated on data collection, model development, and economic assessment, with the German federal authorities providing regulatory and market context. The findings provide a detailed technical basis for the design of future hybrid solar‑BHKW plants, highlighting the importance of continuous operation, adequate storage, and flexible regulation to achieve economic and environmental targets.