Case study-Powering Spain's Largest C&I Energy Storage Plant

Project Summary

TradeInn Smart Shopping Center, a large e-commerce warehouse near Barcelona, Spain, has deployed a landmark solar-plus-storage solution supplied by ATESS. The project comprises two identical integrated systems which together deliver 2.2MWp of photovoltaic (PV) capacity, 1.26MW of power conversion system (PCS) capacity and 5MWh of battery storage on a single site; each unit pairs 1.1MWp of PV with a 630kW PCS and a 2.5MWh battery.

According to the project's EPC partner, this is currently the largest single-site energy storage plant in Spain. Built around the ATESS PCS630 hybrid inverter and the flexible SMC200 PV access solution, the systems maximize on-site solar self-consumption, peak shaving and energy shifting. Based on the EPC's financial forecast, the project is expected to save the asset owner approximately €10,000 per month on grid electricity costs while generating an estimated 2,700 MWh of clean energy every year.

1. Background

TradeInn Smart Shopping Center is the warehouse facility of a major online shopping platform, located near Barcelona, Spain. As a large e-commerce warehouse, the facility runs extensive logistics, storage and data operations that demand continuous, high-volume electricity supply around the clock. In Spain's energy market, where grid electricity prices remain elevated and peak consumption is expensive, an energy-intensive facility operator faces substantial and growing electricity bills, together with increasing pressure to lower its carbon footprint.

2. The Challenge

A facility of this scale faces several interconnected challenges:

· High grid electricity costs: large warehouse loads translate directly into significant monthly grid bills.

· Consumption peaks: concentrated demand during peak periods incurs high grid charges.

· Clean-energy requirements: the operator needed a credible path to power operations with on-site renewable energy.

· Flexible, scalable design: the solution had to integrate PV smoothly, adapt to site conditions and support future expansion.

3. The Solution

ATESS supplied two complete, containerized PV-plus-storage systems for the site. Each system pairs 1.1MWp of PV with a 630kW PCS and a 2.5MWh battery, and comprises the following components:

· ATESS PCS630 hybrid inverter (×1): high-efficiency bidirectional power conversion for charging the battery from solar energy and discharging to the load or grid, with robust, reliable C&I-grade performance.

· ATESS SMC200 solar charger controller (×8): a flexible PV access solution that modularizes solar integration, simplifying system sizing, installation and future expansion.

· ATESS Bypass630 bypass cabinet (×1): ensures continuous power supply for critical loads during outages.

· Isolation Transformer 630 (×1): provides galvanic isolation and grid adaptation for safe, stable operation.

· ATESS Enerlog monitoring system (×1): real-time data acquisition with remote monitoring through a web/app platform.

· Hybrid Container 20 HC Type 1 (×1): an all-in-one containerized solution that minimizes footprint and shortens on-site installation.

Table 1 summarizes the scope of delivery for one system, as confirmed in the project's EPC documentation. Since two identical systems are deployed at the site, the quantities are doubled accordingly. All items are subject to the sales contract.

Figure 1 Scope of delivery (source: ATESS)

With two systems deployed at the site, the project totals 2.2MWp of PV, 1.26MW of PCS capacity and 5MWh of battery storage — forming, according to the EPC partner, the largest single-site energy storage plant in Spain to date.

4. System Architecture

Figure 1 shows the system architecture of each unit. Three groups of PV modules feed the ATESS PCS630 hybrid inverter through SMC200 solar charger controllers. The PCS630 connects to the BYPASS630 cabinet, which supplies the site's load and can exchange power with the grid. The battery is integrated into the system through the isolation transformer. The ATESS Enerlog data acquisition unit collects system data to a local server, enabling real-time monitoring through the web/app platform. In the diagram, red dashed lines represent communication cables and black solid lines represent power cables.

Figure 2 System diagram of each ATESS PV-storage system unit

6. Expected Performance & Benefits

Based on the Barcelona-area solar resource (approximately 1,450 equivalent full-load hours per year) and a PV system efficiency of 0.85, each 1.1MWp system is estimated to generate about 1,356 MWh of alternating-current (AC) energy per year. With two systems, total annual generation is estimated at approximately 2,712 MWh of clean electricity per year. Actual output depends on local irradiance, temperature, shading and operational factors.

According to the EPC partner's financial forecast, the project is expected to save the asset owner approximately €10,000 per month on grid electricity costs. These savings come primarily from:

· Maximized on-site solar self-consumption, replacing grid purchases with solar power.

· Peak shaving and energy shifting: surplus solar energy is stored during the day and discharged during high-price or high-demand periods.

· Reduced reliance on grid electricity, lowering exposure to volatile market prices.

Beyond cost savings, the project advances the owner's decarbonization goals by displacing a meaningful share of grid electricity with on-site solar energy, while delivering reliable power for a facility that operates around the clock.

7. Conclusion

The TradeInn Smart Shopping Center project demonstrates how a large, energy-intensive warehouse can combine PV and battery storage into a single, reliable, containerized solution. The system generates an estimated 2,700 MWh of clean energy every year. For warehouse operators facing high grid costs and consumption peaks, this landmark C&I project is a practical, proven reference for energy cost optimization and decarbonization.