Battery optimization
Background
While the output of solar PV systems only depends on the sun and doesn't allow for any operational choices from the asset operator, batteries on the other hand require decisions on when to charge and discharge, which are subject to some constraints.
Deciding when to charge and discharge in an economically optimal way requires forecasts. For example, to know whether it makes economic sense to charge a battery at a given time, one would need to know whether the charged energy can be sold at a higher price in the future.
Basic operational flow
Tensor Cloud battery optimization generates charge and discharge plans that are used for placing bids on JEPX and when submitting operational plans to the grid operator as part of balancing operations. These plans are then used to control connected batteries in real-time. Battery optimization updates charge and discharge plans every 30 minutes, considering the latest market price and solar forecasts, and telemetry data from each battery system.
By default, our battery optimization considers all assets in the same balancing group when creating charge and discharge plans. That means batteries will also optimize the economic outcomes for other assets that only contain solar systems or electrical loads, as long as they share the same BG.
Integration with site devices
Tensor Cloud relies on hardware devices (EMS) installed on-site to collect telemetry data from batteries and other site components, like solar systems and electrical loads, and send control signals to the battery storage system. While we have established working relationships with a variety of reliable integration partners, Tensor Cloud is vendor agnostic and can work with any EMS that can provide the necessary data and receive control signals. Contact us to discuss your custom integration needs.
Updates to the plan
After placing bids on the day-ahead market based on an economically optimal plan, externalities might change, compared to when the plan was generated.
For example, solar forecasts are updated, battery operational status may be different from what was expected, there may be curtailment requests from the TSO, or market auction prices are confirmed. For this reason, it might be worthwhile to change the initial battery charge and discharge plan, even if that means incurring imbalance. If the imbalance cost is lower than potential incremental revenues, it may be worth to incur imbalance on purpose.
Thus, for periods where a sales plan has already been submitted to the TSO, Tensor Cloud battery optimization will also consider any imbalance costs caused by deviating from the plan when optimizing battery charge and discharge behavior.
Optimization inputs
The optimization considers all operational assets within each grid area in a workspace. It is based on a mixed-integer linear optimization model that has specific inputs:
- Current state of each battery (e.g., state of charge, error/maintenance state)
- Electricity price forecasts for the grid area
- Solar generation forecasts for each asset in the BG
- FIP subsidy for each asset in the BG
- Any generation or sales plans submitted to the TSO
Contact us for more details on the mathematical and logical foundation of our battery optimization service for due diligence purposes.
Battery optimization FAQ
Q: What other markets than JEPX day-ahead do you support?
A: We will start experimental support for the Japanese balancing market in 2025, with the intraday market to follow after that.
Q: Do you support stand-alone battery systems?
A: Tensor Cloud currently supports co-located batteries only but we are planning to add support for stand-alone battery storage within the next 12 months.
Q: How much revenue improvement will we get from co-located storage?
A: The revenue impact of co-located battery storage depends on a variety of factors, including the availability of an attractive FIP premium for your asset, your battery CAPEX, and the specifics of your solar generation profile. Based on our analyses of real customer use-cases, you can expect to get up to >40% increase in annual revenue.
We recommend getting started with our FIP calculator to get a rough estimate on the FIP premium you can expect for your case. After that, you can create a workspace on Tensor Cloud to run detailed techno-economic simulations of your project for a more detailed due diligence.
Q: How long does it take from initial conversation to go-live?
A: This depends on the maturity of your battery storage project, but we typically see a 3-6 month timeline from initial conversation to go-live. The bottleneck is usually not the integration with Tensor Cloud but lead times for battery storage systems, permitting, and the grid connection process.