Understanding how power flows from a large energy source (such as a 100MW capacity power station) to a modular data center that consumes 1MW or less per rack requires breaking down the power distribution system and each of its key components. The following table illustrates this breakdown, from the source (100MW) to individual racks, each consuming a fraction of the total. ### **Power Breakdown from 100MW to Individual Rack** | **Stage** | **Power** | **Key Components** | **Principle/Formula** | **Notes** | | ----------------------------- | --------------------- | ------------------------------------------------------------------------ | ----------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------- | | **1. Power Generation** | 100MW (source) | Power Plant (generation source, e.g., grid, solar, etc.) | Total power available = 100MW | Power is generated from various sources like hydro, fossil fuels, nuclear, or renewable energy. | | **2. Transmission** | ~99MW | Transmission lines (High Voltage) | P_transmission = Power – (Transmission loss) | Transmission losses occur due to resistance in cables, typically 1-3% of total power. | | **3. Substation (Step-down)** | ~99MW | Transformers (Step down to Medium Voltage) | Medium Voltage (MV) = High Voltage (HV) / Transformer turns ratio | Transformers reduce the voltage from transmission level to safer, more manageable levels for distribution. | | **4. Distribution** | ~98MW | Distribution grid (Medium Voltage lines) | P_distribution = P_transmission – (Distribution losses) | Further losses (around 1-2%) happen as power is distributed to local substations or facilities. | | **5. Data Center Substation** | ~98MW | Substation (Step down to Low Voltage) | Low Voltage (LV) = MV / Transformer ratio | Converts medium voltage to low voltage (usually 400V or 480V for data centers). | | **6. Power Feeders** | 1MW per feed | Power Feeder Cables | P_load = P_substation / number of feeds | Feeds distribute power from substation to modular data centers. | | **7. Modular Data Center** | 1MW per module | Power distribution units (PDU), uninterruptible power supply (UPS), etc. | Energy consumed per module = 1MW | Data centers often use redundant power systems (N+1) to ensure uptime. | | **8. Rack Power** | 10kW to 50kW per rack | Racks with IT equipment (servers, GPUs, etc.) | Power per rack = Total DC power / Number of racks | A typical high-density rack consumes 10-50kW depending on its configuration (e.g., GPUs, cooling systems). | ### **Detailed Breakdown with Formulas and Principles** 1. **Power Generation (100MW)**: Power generation is the source of energy that provides 100MW. This power can come from various sources such as fossil fuels, renewable energy (solar, wind), or hydroelectric plants. The key principle is that this is the total power available before any transmission losses occur. $ P_{\text{generated}} = 100MW $ 2. **Transmission**: High voltage (HV) transmission lines transport power from the source to distribution centers. Transmission loss occurs due to resistance in the lines, typically 1-3%, depending on the distance and efficiency of the transmission network. $ P_{\text{transmission}} = P_{\text{generated}} - \text{losses} \approx 100MW \times (1-0.02) = 98MW $ (assuming 2% loss) 3. **Substation (Step-down)**: A transformer steps down the voltage from HV to MV (Medium Voltage) for distribution. The turns ratio of the transformer determines how much the voltage decreases. $ V_{\text{medium}} = V_{\text{high}} / \text{turns ratio} $ This step reduces voltage to manageable levels (e.g., 33kV) for local distribution. 4. **Distribution**: Power is distributed via medium voltage lines to local substations or directly to data centers. There’s an additional 1-2% power loss in the distribution network. $ P_{\text{distribution}} = P_{\text{transmission}} \times (1 - 0.02) = 98MW \times 0.98 \approx 96MW $ 5. **Data Center Substation**: At the data center, another transformer steps down the power from medium voltage (33kV) to low voltage (400-480V), which is appropriate for use in IT equipment. The substation will split this power into multiple feeders for modular data centers. 6. **Power Feeders**: Each feeder typically supplies around 1MW to modular data centers. If the data center requires multiple 1MW modules, several feeders will be used. This is the stage where power is directed to specific IT infrastructure. $ P_{\text{feeder}} = P_{\text{substation}} / \text{number of feeds} $ 7. **Modular Data Center (1MW per module)**: Inside the modular data center, power is distributed to PDUs (Power Distribution Units), which supply power to servers, racks, and cooling systems. The power for each module is roughly 1MW. 8. **Rack Power (10kW - 50kW per rack)**: Depending on the density of the rack (number of servers, GPUs, etc.), each rack in the modular data center consumes between 10kW and 50kW. High-performance computing racks with multiple GPUs can consume power on the higher end of this spectrum. $ P_{\text{rack}} = \frac{P_{\text{module}}}{\text{number of racks}} $ For example, if the 1MW module contains 20 racks, each rack would consume around 50kW. --- ### **Key Takeaways:** - **Transmission and distribution losses** must be factored in when planning large-scale power infrastructure for data centers. - **Substations and transformers** are crucial for stepping down power from high voltage (for long-distance transmission) to low voltage (for direct use in servers and IT equipment). - **Modular data centers** often use **redundant power systems** (N+1) to ensure reliability, which adds extra complexity to the power distribution system. - **Rack-level power consumption** can vary widely depending on the type of IT equipment and its cooling requirements. High-performance racks can consume up to 50kW, while more standard racks consume 10-20kW. This structured breakdown provides an overview of how power flows from a large capacity (100MW) generation source down to individual racks in a modular data center. Each stage has its own cost, losses, and operational considerations that must be accounted for during the planning and setup of data center infrastructure.