What are residential energy storage systems and the components in them

The household photovoltaic field is an important part of the photovoltaic market, and the global household photovoltaic installation has returned to rapid growth in the era of parity. From the perspective of development stage, the penetration rate of household photovoltaic in some developed regions has been high. The development mode has changed from subsidy driven, full access to the Internet to self economic driven, spontaneous self use.

The demand for supporting energy storage is gradually emerging. However, China’s household photovoltaic market started late, and after 2019, it will witness explosive growth driven by the economic nature of the subsidy policy itself, financial penetration and other factors.

What is the residential energy storage systems? This article will introduce the core components, product types, technical routes, business models, pricing models and demand volumes of residential energy storage systems in detail.

Core components

The core of the household optical storage system is photovoltaic+battery+energy storage inverter. The residential energy storage systems and household photovoltaic are combined to form a household optical storage system.

The optical storage system mainly includes electric core, energy storage inverter (bidirectional converter), component system and other parts.Typical systems are generally 5kW (modules+inverters) with 10kWh (energy storage batteries) or 10kW+10kWh.

The battery cell is the core of the home energy storage system, accounting for about 45-50% of the cost; The energy storage converter can control charging and discharging, and conduct AC/DC conversion, accounting for 10-15% of the cost;

The module system, i.e. photovoltaic system, is used for solar power generation, with the cost accounting for about 20-25%; The installation cost will increase from 10000 in 2021 to about 20000, accounting for 15-20%.

Product type

The residential energy storage systems products include integrated machine and split type.

● Integrated machine type:

The integrated machine is an integrated system that places the photovoltaic inverter, battery and controller inside.It can display the working status quickly and intuitively through the touch screen, modify the parameters and allow multiple working modes for easy use. Generally, there are three working modes: solar energy priority mode, AC priority mode and SE priority mode (peak load shifting mode).

● Split type (inverter+battery system):

The household split unit battery and inverter are installed separately. Users can match the inverter of residential energy storage systems according to their own needs. In addition, they can match the switching power supply or inverter as the standby power supply.

Generally, it includes four types: hybrid home photovoltaic+energy storage system, coupled home photovoltaic+energy storage system, off grid home photovoltaic+energy storage system, and photovoltaic energy storage management system.

Technology route

The mainstream technology route of residential energy storage systems is lithium iron phosphate, and sodium ion and lithium ferromanganese are new routes in the future.

The technical route of energy storage battery includes lithium ion, lead battery, liquid flow battery, etc. At present, lithium iron phosphate lithium battery is more in line with the design requirements of energy storage battery than ternary lithium battery due to its high safety, long cycle life and other characteristics. It is the mainstream development route of energy storage battery.

Tesla energy storage battery is also gradually changing from ternary to iron lithium route. In addition, some companies, such as CATL and Pylon Tech, are already developing and testing sodium ion and ferromanganese lithium batteries. It is expected that the technical route of energy storage batteries in the future is expected to be further improved.

Business model of residential energy storage systems

The sales model includes direct sales and distribution, brand and channel building advantages. The sales models in the residential energy storage systems industry chain are as follows.

Cell/energy storage inverter supplier

The inverter / energy storage cell suppliers are divided into To C and To B. To C generally integrates the home storage system, builds its own channel and promotes its own brand, which has certain consumption attributes. To B is a general product supplier, which sells products to integrators without consumption attributes, and earns material costs and processing fees.

System Integrator

System integrator does not have complete product production capacity. They can purchase electric cells or energy storage inverters. Some enterprises also produce some components by themselves for simple system product integration. However, they have channel sales resources and rely on existing channels to cooperate with local dealers and installers.

Dealer/Installer

Dealers/Installers connect with upstream integrators, deliver to the end users after the installation construction is completed, and earn sales and installation fee commissions.

Pricing model

The price difference of residential energy storage systems between China and other countries is the largest, which is higher than industrial and commercial energy storage and MW energy storage. Other countries are nearly 133% higher than China (based on the highest price). The price is mainly CIF, and the seller bears the main risk.

At present, household storage products within 30kWh are priced at 1.0-1.5 RMB/Wh in China and 2.0-3.5 RMB/Wh in other countries, including the electric core, BMS and shell, and the 10 year warranty of the connecting harness. The quotation methods include EXW, FOB, CIF and DDP. The quotation consists of goods pricing, accessories, FOB/CIF/DDP, etc. At present, CIF offers are the majority, and sellers bear high risks.

Compared with China, terminal pricing in other countries is higher, with 30% – 50% price increase for dealers and installers. At present, the price in China is low, with a gross margin of 20% – 30%. The gross margin of the all-in-one machine is higher than that of the battery or inverter. Under the pricing model in other countries, labor wages and travel expenses will increase costs.

In addition, repair/after-sales expenses of about 5% should be considered. The sales price in other countries will be increased by 30-50% respectively by dealers and installers.

You can contact us to get a quote for your specific needs and application scenarios.

Demand volume

The demand for residential energy storage systems is growing rapidly, with a year-on-year growth of 56% in 2021. The data shows that in 2021, the global installed capacity of energy storage will be about 10GW/22GWh, with a year-on-year growth of 84%/105%. Among them, the distributed installed capacity of energy storage will be about 2.5GW/5.6GWh, with a year-on-year growth of 45%/40%.

The household installed capacity of distributed energy storage will be about 1.9GW/4.4GWh, with a year-on-year growth of about 53%/56%.The global household storage is booming. The main driving factors are from two aspects, one is the continuous increase of policy support, and the other is the economic drive of high returns.

The policy support of tax relief and fund subsidy was given, and the household savings economy was improved with the continuous rise of household electricity prices. Countries around the world have launched relevant policies to stimulate the installation of residential energy storage systems.Relevant policies can be divided into indirect tax relief and direct fund subsidy, so as to reduce the installation cost of household storage.

In addition, under the trend of rising global residential electricity prices, the spontaneous use of household storage can save more electricity expenses. Therefore, the yield of household storage is constantly rising, thus stimulating the continuous growth of household storage units.