Zero Grid Export: A Guide to Unlocking Solar Self-Consumption

Nov 22, 2023 | Applications

The surge in popularity of solar energy is undeniable for both households and businesses, as they increasingly harness the benefits of this renewable resource. The intuitive to optimize solar energy usage has never been more pronounced in response to environmental consciousness and economic prudence. This blog post seeks to shed light on the various solutions available for achieving zero grid export and maximizing solar self-consumption.

 

I.Navigating Solar Optimization? Grasp the Core Concepts!

When delving into the optimization of solar energy usage, phrases like Zero Export, Zero Grid Export, and Solar Energy Self-Consumption commonly arise. It’s essential to grasp these concepts before immersing ourselves in the solutions for enhancing solar efficiency.

With the installation of a solar system, solar energy is generated during daylight hours, primarily catering to the operational needs of various loads. When the load demand surpasses the solar generation, the grid seamlessly supplements the power requirements. Conversely, during times of surplus solar energy, the excess is directed back to the grid.

The accompanying chart illustrates typical patterns of solar energy generation and household energy consumption. Notably, consumption peaks are observed between 6-8 o’clock in the early morning and night. The majority of solar generation occurs between these consumption peaks, resulting in surplus solar energy often being sent back to the grid.

Solar Generation and Household Consumption

In regions with feed-in tariffs, returning energy to the grid to some extent offsets the portion drawn from the grid, resulting in a bill that reflects a lower consumption. While this may seem advantageous, the reality unveils a subtler truth: power drawn from the grid is billed at a higher energy retailer price, while surplus solar power exported to the grid fetches a considerably lower rate. The opportunity cost of selling to the grid rather than fully utilizing solar energy can be substantial.

 

1. Zero Grid Export

Zero grid export is a scenario where on-site demand fully consumes all solar-powered system generation, ensuring no excess is fed back into the grid. In such a case, the solar energy generation and energy consumption pattern would seem close to the below chart.

Decreased Grid Export

Beyond the economic concerns, sustainability also matters in this context, as sending energy back and forth between the on-site system and the grid incurs potential waste during energy transmission.

By achieving zero grid export, we not only optimize economic benefits but also curtail unnecessary environmental impact.

 

2. Solar Energy Self-Consumption

Solar energy self-consumption involves efficiently utilizing solar-generated power within the premises where it is produced. It is a strategic approach to reduce dependence on external grids. Embracing zero grid export unlocks additional energy consumption opportunities and also enhances energy independence, bringing us closer to the goal of achieving solar energy self-consumption.

 

II.Solutions and Devices for Zero Grid Export

Achieving zero grid export involves either storing surplus energy for future use or synchronizing appliance consumption to align seamlessly with solar generation.

Appliances Used for Optimizing Solar Energy Usage
Appliances Used for Optimizing Solar Energy Usage

 

1.Solar Battery + Smart Energy Monitors

Smart energy monitors play a pivotal role in real-time energy data monitoring. Bi-directional monitors, attuned to solar system activity, seamlessly communicate with solar batteries, triggering charging cycles when surplus energy is detected. Solar batteries serve as substantial reservoirs, storing ample energy for subsequent consumption, forming a robust strategy for achieving zero grid export.

It is worth mentioning that the upfront cost of investing in a solar battery system, particularly one with extensive capacity, may deter some.

 

2.Smart EV Charger + Smart Energy Monitors

As electric vehicles become common in households, private EV chargers have followed suit for convenient charging. The battery packs in electric vehicles store energy crucial for powering the car, with Range Per Charge a pivotal consideration. Smart EV chargers, equipped with IoT features, can seamlessly receive signals from smart energy monitors. This functionality allows for dynamic adjustments in charging status and speed, effectively maximizing solar self-consumption.

Given that surplus solar energy typically coincides with daytime hours and workdays when electric vehicles are away for commuting, home charging during these periods might be impractical. In such scenarios, a holistic assessment of other appliances becomes necessary.

 

3.Water Heater + Energy Diverter + Smart Energy Monitors

The water heater is a household necessity, which fulfils needs such as supplying hot water for kitchen use and bathing. Particularly, water heaters with a water cylinder are popular for their ample hot water storage, ensuring availability at any time. Moreover, these water heaters hold significant potential for energy consumption and optimization.

In this solution, the water heater often collaborates with an energy diverter, known by various names such as immersion optimizer, solar PV optimizer, or power diverter. Essentially, this intelligent device harmonizes with smart energy monitors, receiving real-time data to seamlessly adjust heating power. The synergy between these components creates an optimized system, ensuring the water heater operates precisely in alignment with energy generation patterns.

 

4.Non-smart Appliances + Smart Relay Switch + Smart Energy Monitors

For homeowners seeking a more budget-friendly approach or facing limitations in retrofitting existing appliances, there exists a viable alternative. This option allows manipulation of non-smart appliances, even those devoid of any intelligent features.

A smart relay switch is an intelligent device designed to control the electrical flow in a circuit. It typically communicates wirelessly or through a network connection, enabling users to remotely manage the power supply to specific devices or appliances. Smart relay switches are often integrated into smart home systems, allowing for automated control and optimization of energy usage.

By introducing a smart relay to the circuit of appliances resorted to for solar energy optimization — think dishwashers or washing machines — an innovative solution unfolds. Through smart energy monitors, users can configure the relay to switch these devices on or off, based on data from smart energy monitors.

Compared with the first two solutions, this one offers enhanced flexibility and requires minimal investment. However, it’s essential to note a limitation — only on and off functionalities can be controlled, without the capability to adjust operating power. This means that irrespective of the rate at which solar energy is generated, the working power of the loads remains constant.

 

III.Key Device to Solar Energy Self-Consumption

Regardless of the chosen solution, the pivotal device is the smart energy monitor. Functioning as a real-time meter, it plays a crucial role in monitoring solar generation and load consumption. The energy monitor acts as a scout,facilitating adjustments to load operations through timely and insightful messages.

Multiple types of energy monitors are commonly seen in the market, and the most recommended one takes the form of a compact energy sensor, such as Bituo Technik’s SPM.

SPM

SPM Smart Energy Sensors

Its easy installation, strategically fitting into existing or new power distribution boards without occupying valuable Din-rail space. Offering both wireless and wired communication options, the SPM seamlessly adapts to diverse setups.

SPM 01 and 02 Installation

Single-phase and Three-phase SPMs Installed in a Distribution Board

 

The SPM doesn’t just stop at easy installation — it unfolds a myriad of functions for comprehensive energy management, including historical data recording and customizable alarms. Leveraging Over-The-Air (OTA) capabilities, this smart energy sensor holds the potential to continually evolve within the IoT energy management ecosystem, ensuring it stays at the forefront of innovation and versatility.

 

IV.Conclusion

Achieving zero grid export necessitates thoughtful consideration and the adoption of suitable solutions. Whether leveraging smart energy storage or managing smart appliances or non-smart loads, each plays a pivotal role in achieving efficient solar self-consumption. The crucial guidance for optimization comes from smart energy monitors, which provide essential data insights.

This journey toward unlocking solar self-consumption extends beyond mere economic intentions; it embodies a broader commitment to fostering a more sustainable world. By embracing these thoughtful approaches, we not only enhance our individual energy efficiency but collectively contribute to the larger goal of building a greener future.

Related Products

SPM01 (1P+N, 63A)

SPM02 (3P+N, 63A)

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