In order to understand the cost of wall mounted energy storage battery, we need to understand the accounting structure of its cost? Unlike independent photovoltaic, energy storage cells lack a set of widely accepted benchmark measures, such as USD per watt of installed capacity or average wall mounted battery cost. The cost of the energy storage battery may vary according to the total powerwall battery capacity of the system (expressed in dollars per kilowatt hour (KWH)) and the charge or discharge rate (expressed in dollars per kWh). Second, some users may prefer to optimize their systems to achieve longer discharge time, while others may have peak demand and want to optimize their storage solutions to obtain power (kw) instead of powerwall battery capacity (KWH). In view of the diversity of family preferences and load distribution, the use of a single indicator may lead to the accuracy of cost reporting, making it difficult to compare between different systems. Therefore, we use the total installed price as the main indicator, rather than the indicator normalized to the system size.
After understanding the accounting components of household energy storage batteries, we adopted and studied two main situations of wall mounted energy storage battery: one is small battery (3 kW / 6 KWH) and the other is large battery (5 kW / 20 KWH). For each, we tested the sensitivity of two sets of alternatives: DC or AC coupled configurations, and retrofits or new installations. The difference between DC and AC coupling determines whether the battery directly stores the power from the photovoltaic panel or first converts it into AC power, thereby allowing AC charging from the photovoltaic panel and the grid.
The small power wall battery box is designed for the self consumption of typical customers, including peak demand adjustment and service time conversion, while the large battery box is designed to support greater backup energy demand to improve fault recovery capability.
We found that the benchmark price of a small lifepo4 powerwall box using a 5.6kw solar photovoltaic array and a 3kW / 6kW lithium-ion battery is about twice that of an independent grid connected 5.6W solar photovoltaic system (see Figure 1). The price of the DC coupling system ($27703) is $1865 lower than the price of the AC coupling system of the new photovoltaic plus energy storage device ($29568).
The price premium of AC coupling system is mainly due to the hardware and labor costs related to the additional grid connected inverter required for AC coupling. However, when comparing AC and DC coupled systems, the installation price is not the only consideration: AC coupled systems are more effective in applications where photovoltaic energy is usually used for power generation, while DC coupled systems are often more effective in applications where photovoltaic energy is stored and later used。
How much is the power wall mounted energy storage battery cost?The specific cost is affected by the needs of customers, such as the capacity and functionality of wall mounted batteries
