With the rapid development of the solar photovoltaic (PV) industry in the past decade, the different uses of photovoltaics have flourished. The PV energy storage system is the combination of photovoltaic power generation and energy storage batteries and is beginning to be widely used in the industry by households. These home systems may or may not be connected to the public electricity grid. Large renewable energy corporations have developed their own PV energy storage systems, such as, SMA Solar Technology AG in Germany, BOSCH, BYD in China, and Neovoltaic. In 2012, ReneSola launched two types of household PV energy storage systems which are being sold to homeowners in Germany, Australia, United Kingdom, and the USA. Solar PV panels are installed as part of the PV energy storage system in your home and can help to lower monthly energy bills. At the end of this article, are images of ReneSola PV energy storage systems.
What is a Household Photovoltaic Storage System?
A household PV energy storage system is a combination of PV and energy storage to meet the needs of families who want to power their own homes. The extra or leftover energy can be stored in the battery or sold to the public grid. The basic interface system includes: PV input, electricity input, and electricity output. The main system components are the solar control unit, battery energy storage control unit, an inverter, energy and system control unit, and remote monitoring unit. Household PV energy storage system supports the concept of families powering their own homes with solar energy and homes can be in remote environments. This is different from the distributed PV power generation system which refers to electricity that is produced at or near the point where it is used.
Increasing Development of Household Photovoltaic Energy Storage Systems
Household PV energy storage systems have accelerated in development in the last two years for the following reasons:
1. Government guidance and support
In earlier years, Germany and the USA had launched the ‘Million Roofs Plan’ which directly led to a surge in the renewable energy power generation markets of Germany and the USA. Japan and Germany have proposed before to achieve the full realization of the denuclearization to achieve strategic energy transformation. The combination of solar energy and energy storage system achieve the features of clean, sustainable, and low dependence; and has become the preferred alternative to nuclear power. This also improves the popularity and enthusiasm for solar energy storage systems. In recent years, many countries in the world that emphasize the use of solar power have lowered feed-in tariffs (FIT) and further reduced costs of solar power generation, encouraging more homeowners to use the electricity for themselves rather than selling the electricity to the national grid. For PV energy storage systems, the German KFW bank along with the German Federal Ministry for the Environment, Nature Conservation and Nuclear Safety (BMU) support the distributed PV energy storage deal that took effect on May 1, 2013. This marks Germany’s distributed PV policy’s expansions from only subsidizing power generation units to include subsidies for protecting solar energy storage units. And this has guided other countries in the use of PV energy storage systems.
2. Initiatives of related industry sectors
First, electricity companies to ease the pressure on the supply of energy at peak periods and to lower the impact of mid-day peak electricity generation on the grid connected centralized ground and roof-mounted solar systems, with an attitude of ‘welcome, support, and service’, promote households to use solar energy storage systems. The storage of energy will help alleviate the pressure on the grid, especially in the afternoon peak hour of PV power output. After being stored in the storage facility, the electricity will be discharge at night during peak hours, achieving PV optimization of load matching and power generation. Second, household storage equipment manufacturers have developed household energy storage systems that suit the needs of various countries, such as the most common PV products of the 3 – 10kw PV inputs and the 8 – 20kwh energy storage. Third, PV module manufacturers are proposing higher demands on the production of modules, including improved power efficiency and longevity, and reduced production costs of modules. Fourth, inverter manufacturers have proposed higher demands on inverter production, including improved conversion efficiency, longevity, and reduced production costs of inverters. Fifth, as lithium iron phosphate batteries are the most commonly used in household PV energy storage systems, the batteries’ features of good safety performance, long life cycle, good performance at high temperatures, and high energy density makes the entire system have greater longevity and guarantees its security.
3. Economic Development and Solar Market Growth
As the economy continues to develop, the increase of the cost of traditional power generation PV costs shows a downward and compared to traditional power generation costs, it has been found that in many countries the price of PV electricity during the day is already very competitive. The ‘grid parity’ era has arrived. In Australia, Denmark, Germany, Hawaii, Italy, and Spain, the cost of PV power generation is now less expensive than residential electricity. Based on the 2015 forecast of the cost of PV power generation, this will be the case for California, Brazil, France, Japan, and Turkey even when electricity fees do not increase, This makes household energy storage system more
4. Increase in Users Understanding of PV Power Generation and its Environmental Impact
With oil, natural gas, and other non-renewable energy shortages, the awareness of saving energy, and the use of and investment in large centralized PV power plants and rooftop PV power plants, ordinary people are slowly beginning to realize that PV power generation is the best alternative to traditional energy sources. People will begin to see that household PV energy storage systems are economical and feasible. With government subsidies for PV fixed tariffs, residents can be encouraged to power their homes with PV energy storage systems and benefit by selling electricity to the utility company.
According to the Japanese market research data, as many as 70% of people expect to be using solar energy or other renewable energy generations systems or home energy storage systems to provide all the energy needed for living. The reason for their vision is not just because household storage battery can be used for emergency power in the event of disasters, but rather through the use of a combination of solar power systems to promote the use of renewable energy sources and to achieve ‘energy creation, energy storage, energy efficiency, and smart energy’.
Vision for the Future
It can be predicted that with the advent of the photovoltaic ‘grid parity’ era and the technological innovation of household PV energy storage products, and the additional guidance and policy support to boost the photovoltaic and energy storage products, PV household energy storage systems need to adapt to the times and develop into family oriented and people friendly products. PV energy storage systems will become an affordable way of green energy for every person.
ReneSola manufactures its two types of PV energy storage systems which are sold in the USA, Europe, and UK markets. See below images of ReneSola PV energy storage systems. If you have any questions regarding these products or would like to inquire about purchasing one, please send us an email at firstname.lastname@example.org