What is a home energy storage system?
Home energy storage is the storage of electrical energy for use when needed – also known as electrical energy storage products or “battery energy storage systems” (BESS), hereinafter referred to as home storage. The core component of a BESS is a rechargeable battery, typically a lithium-ion or lead-acid battery. The other components are the inverter, a control system that intelligently controls charging and discharging.
With energy storage in the average home, we can realize the concept of distributed generation, ease the pressure on grid transmission, reduce the use of fossil fuels, and is a necessary decentralization initiative to achieve carbon neutrality or zero-neutrality.
Benefits of home storage systems:
Overcoming Transmission Losses: Electricity losses from power stations to households are inevitable, especially in densely populated metropolitan areas where it is not possible to build power stations within them, and transmission losses are even greater. However, if households are encouraged to generate and store electricity on their own, and external transmission is reduced, then transmission losses can be significantly reduced, and grid transmission can be made efficient.
Household energy storage, if connected to the grid and feeding surplus electricity from household generation into the grid, can greatly relieve pressure on the grid: 1) by providing power supply response during peak hours, it can reduce the use of inefficient diesel generation; and 2) by using an industrial frequency that matches the local grid, such as 50Hz or 60Hz.
Reducing the use of fossil energy: Households storing their own power generation can greatly improve the efficiency of electricity use, while the technology of generating electricity from fossil energy sources such as natural gas, coal, oil and diesel will be phased out.
Reducing energy bills: households storing their own power generation can dramatically reduce grid electricity use.
Avoid peak tariffs: Storage batteries can store electricity during low peak periods and discharge it during peak periods.
Realize the independence of electricity consumption: Families will store solar power generation during the day and use it in the evening, and at the same time, it can be used as a backup power source in case of sudden power outage.
Deficiencies in home storage systems:
Environmental Impact of Batteries: Early home storage systems generally used lead-acid batteries, which have the advantage of being highly recyclable – 99% of lead-acid batteries in the United States are recyclable. However, the lead and sulfuric acid electrolytes in lead-acid batteries are extremely harmful to the environment. In addition, lead-acid batteries have a short lifespan and are gradually being replaced by lithium-ion batteries.
However, although lithium-ion batteries have a long service life, they are not recyclable (or it is difficult to do so), and some lithium-ion batteries contain nickel, cadmium and manganese, which will also cause pollution to the environment.
High upfront cost: Today’s battery cost is very high, ranging from $400-700/kWh.
Complicated installation: some home storage systems have to be equipped with additional inverters, and smart monitoring devices.
Large footprint: the size of a system is about 500x250x700mm (not counting the solar panels), and at this stage, only single-family houses can meet the space requirements.