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x Prokon

Optimizing Multi-market trading for solar plus storage

SUCCESS STORIES

Combining solar power plants with energy storage is a concept that is gaining increased attention as it streamlines the integration of solar power into our power grid. This case study sheds light on an innovative co-location project that we are realizing together with Prokon within the framework of a German innovation tender. The focus lies on the joint optimization and trading of solar energy in combination with a battery storage system.

The expansion of renewables cannot succeed without the meaningful integration of these sources into our existing system. The fact that at the moment renewable sources must be partially curtailed during times of peak generation or struggle with price cannibalization highlights a symptom of our power system's lack of sufficient flexibility to manage the intermittency of renewable energy.

PROJECT DETAILS

Asset Owner: Prokon

Route to Market Provider: suena

Asset location: Germany

System: Solar Park / Solar Extension + Battery

Solar Power (Tender): 6MWp

BESS Power: 2MW/2.16 MWh

Monetization

Trader: suena Autopilot

Involved Markets:

-  DA

-  ID Auction

-  ID Trading

-  Future Markets: aFRR positive (In this project, we will test providing only positive aFRR.)

Adding an energy storage system to a solar park is a good idea from both an energetic and economic perspective: energy shifting not only ensures the security of supply, e.g. for self-consumption -, even during times of unavailability of renewable sources. The energy storage system also offers further revenue opportunities and advantages to the plant, such as:

  • Aiding in imbalance management by offsetting forecast errors in energy generation to reduce financial risks.

  • Improving the capture rate (a measure of the ratio between the average electricity price (in €/MWh) that a project achieves, the Capture Price, to the Spot Price that a project attains, expressed as a percentage).

  • Mitigating yield and profit compression in solar parks with energy shifting, which manifests in continuously reduced prices due to numerous solar assets entering the market.

  • Exploiting price arbitrage during times when the storage or parts of it are not in use. In this project, as an innovation tender project, there are special requirements here, as the storage system may only charge from renewables and not from the grid.

  • Participating in grid services for frequency containment; in this case of an Innovation Tender, only aFRR positive is possible to comply with the restriction to not charge from the grid.

  • Optimizing the use of limited grid connection capacities, allowing energy storage during peak production and release when needed, particularly vital in areas with constrained grid infrastructure.

Co-locating a battery storage system is the first step towards enabling a 100% renewable energy transition. The second step involves effectively managing the flexibility and trading the energy provided by the solar-plus-storage plant. Besides the economic success story, the project also contributes to making our energy system more efficient, resilient, and sustainable.


Different Types of Co-Location

Type 1: Battery and solar plant share one grid connection, but each has a fixed power allocation and therefore do not influence each other. Energy in the battery storage system is marketed independently from the solar plant.

Type 2: Battery and solar plant share one grid connection and influence each other. The storage can be charged from the grid and the solar plant. Energy is traded on multiple markets, while storage and solar plant are regarded together for the marketing strategy.

Type 3: This is the case used for the Prokon Walshausen Project and typical for innovation tenders for solar and storage. Solar and storage share one grid connection and one meter, are therefore marketed together, but the storage can only be charged by the solar plant and not from the grid.

Co-locating Energy Storage with Solar - A Good Idea from an Energetic and Economic Perspective

ABOUT

Prokon

Prokon Regenerative Energien eG, Germany's largest energy cooperative, has been at the forefront of sustainable energy since its foundation in 1995. With a strong focus on wind energy, the cooperative manages over 360 wind energy installations with a significant installed capacity. Established in 1995 and having transitioned to a cooperative model in 2015, Prokon has been a leader in renewable energy, managing 410 wind energy installations in Germany, Poland and Finland. Besides wind energy, their portfolio includes solar and biomethane projects, showcasing their dedication to diversifying renewable energy sources.

Prokon's mission is centered around promoting a fully sustainable energy supply, demonstrated through their commitment to renewable energy and the operation of wind and solar parks. Additionally, they serve as an electricity supplier, emphasizing genuine green energy.

Further highlighting their commitment to genuine green energy is the solar plus storage project Walshausen going live in September 2024, in which, together with suena, they want to early adopt and understand the value of a co-located battery storage to evaluate future investment in the technology.

suena is the route to market provider for Renewable Energy and Battery Storage

Forecasts

Taking into account market and generation forecasts, real-time market data, and battery aging models, the Autopilot determines and executes the optimal trading schedule.

Trading the Asset's Energy - Using a Multi-Market Approach

The marketing strategy for this project involves the day-ahead, the intraday, and continuous intraday market. Trading decisions are based on the suena Autopilot, which combines forecast and technical data to optimize the dispatch schedule. The first decisions are made on the day-ahead market, then bids and offers are placed on the intraday market, and then continuous intraday trading is performed in the markets with 15-minute resolution. Any fluctuations and forecast errors are balanced out here, and the dispatch schedule is continuously optimized for every time step.

100% Transparency in Energy Trading

Transparency is a key issue in energy trading. To gain a comprehensive insight into all trading activities in real time, we offer Prokon a comprehensive energy trading dashboard to view live data as well as monthly and annual summaries.

In a 15-minute resolution, prices, trading instructions, and state-of-charge levels that were executed by the storage system, as well as a forecast of planned and expected activities up to 24 hours into the future, are shown.

Balancing Group Management

The project is integrated into the balancing group for which suena is responsible. suena acts as the balancing responsible party.

The Route to Market: We Offer Our Epex Access

As a member of Epex and holder of trading licenses, suena has its own market access through which the energy is marketed.

We are pleased to add the Prokon solar + storage project to our portfolio as our first co-location project where we have the chance to mutually learn from each other and generate valuable knowledge about the added value that a co-located storage provides.

Dr. Lennard Wilkening (CEO & CO-Founder of suena)

Innovation Tender

The German tendering system for solar plant projects is a competitive process where solar energy companies submit bids for building solar power projects. The government selects the most cost-effective and feasible proposals, granting winning bidders a contract with a fixed electricity price. This not only kick-starts the solar plant project but also supports Germany's commitment to renewable energy and carbon emission reduction.

Fulfilling Innovation Tender Requirements

Since 2021, facilities that collect temporarily stored energy generated exclusively from renewable energies and convert it into electrical energy are eligible for the tendering process. Therefore, and because they require imbalance management, co-location storages are fundamentally more sensitive in marketing but will gain relevance especially due to limited grid-connection infrastructure. suena manages the marketing of the solar park and storage in accordance with all specifications of the tendering process.

PROJECTS STEPS

AN IMPACTFUL PROJECT

AN IMPACTFUL PROJECT

Collaborating with Prokon is both lucrative and environmentally beneficial. With the project, we add to the solar capacity and simultaneously enhance the integration of renewable energy sources. Our automated trading system significantly contributes to reducing energy imbalances by swiftly adjusting to forecast changes in their portfolio. This not only bolsters grid stability but also aligns with our commitment to a sustainable energy future.

"Transparency and the mutual willingness to share knowledge and our communication with Prokon are key in these environmental achievements," says Hanna Kammering, Project and Customer Success Manager at suena. This project shows how innovative energy strategies can foster a more sustainable and efficient energy landscape.

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