What is the cost of electricity storage battery per kWh? Do you even need a storage for your photovoltaic system? Here you will find the answers.
What is the Purpose of Electricity Storage?
Photovoltaics generates electricity from sunlight. Accordingly, a photovoltaic system can only generate a lot of energy when the sun is shining. This applies especially to the time from morning to afternoon. In addition, you have the greatest electricity yield in spring, summer and fall. Unfortunately, these are also the times when your household needs comparatively little electricity. Electricity consumption is highest in the evening hours and during the dark winter months. So, in summary, this means:
● The system delivers too little electricity just when you need it.
● On the other hand, too much electricity is produced during the time when demand is lowest.
Therefore, the Legislature has created the possibility to feed solar power that you do not need yourself into the public grid. You receive a feed-in tariff for this. However, you must then purchase your electricity from the public energy suppliers at a cost during times of higher demand. The ideal solution to be able to effectively use the electricity yourself is an residential battery backup for your photovoltaic system. This allows you to temporarily store excess electricity until you need it.
Do I Necessarily Need an Residential Battery Storage for My Photovoltaic System?
No, photovoltaics also works without electricity storage units. However, in this case you will lose the surplus electricity in high-yield hours for your own consumption. In addition, you have to purchase the electricity from the public grid at times of highest demand. You get paid for the electricity you feed into the grid, but you then spend the money on your purchases. You may even pay more for it than you earn by feeding it into the grid.
In addition, your income from the feed-in tariff is based on legal regulations, which can change or be completely cancelled at any time. In addition, the feed-in tariff is only paid for a period of 20 years. After that, you have to sell your electricity yourself through brokers. The market price for solar power is currently only about 3 cents per kilowatt hour.
Therefore, you should strive to consume as much of your solar power as possible yourself and therefore buy as little as possible. You can only achieve this with a electricity storage for home that matches your photovoltaics and your electricity needs.
What Does the kWh Figure Mean in Relation To Home Electricity Storage?
The kilowatt hour (kWh) is a unit of measurement of electrical work. It indicates how much energy an electrical device generates (generator) or consumes (electrical consumer) during one hour. Imagine a light bulb with the power of 100 watts (W) burns for 10 hours. Then this results in:
100 W * 10 h = 1000 Wh or 1 kWh.
For home battery storage systems, this figure tells you how much electrical energy you can store. If such a electricity storage battery is specified as 1 kilowatt hour, you can use the stored energy to keep the above-mentioned 100-watt light bulb burning for a full 10 hours. However, the electricity storage battery must be fully charged.
Costs for A Residential Electricity Storage Battery Per kWh
The cost of residential electricity storage unit varies widely, depending on the solar battery provider. In the past, lead batteries specially developed for solar power storage were used. Here, you have to expect costs of 500 to 1,000 dollars per kWh when purchasing a solar power storage system.
Due to the higher efficiency, the higher usable capacity and the longer lifetime (higher number of charging cycles), lithium-ion battery are generally used today. With this type of residential electricity storage unit, you have to calculate with acquisition costs of 750 to 1,250 dollars per kWh. BSLBATT offers distributors a lower price for 48V lithium battery storage system, Join our network of distributors for free and earn profits.
When is An Electricity Storage Battery Worthwhile?
As studies have shown, you can only use 30 % of the electricity generated by your photovoltaic system yourself. With the use of a electricity storage battery, this value increases to 60 %. To be profitable, the kWh from your electricity storage unit must not be more expensive than the kilowatt hour purchased from the public grid.
Photovoltaic system without electricity storage battery
To determine the amortization of a photovoltaic system without electricity storage battery, we use the following assumptions:
● Cost of solar modules with 5 kilowatt peak (kWp) output: 7,000 dollars.
● Additional costs (for example connection of the system): 750 dollars
● Total costs for the acquisition: 7,750 dollars
Photovoltaic system with residential battery backup
We assume the same PV system data as mentioned in the previous point. A rule of thumb says that the electricity storage battery should have the same storage capacity as the power of the photovoltaic system. Thus, our system with 5 kW peak includes a battery storage unit with a capacity of 5 kW peak. According to the average price of 1,000 dollars per kWh of storage capacity mentioned above, the storage unit costs 5,000 dollars. The price for the plant thus increases to a total of 12,750 dollars (7,750 + 5000).
In our example, as already mentioned, the plant generates 4,750 kWh per year. However, with the help of the electricity storage battery, the self-consumption increases to 60 % of the generated electricity quantity or 2,850 kWh (4,750 * 0.6). Since you don't have to buy this amount of electricity from the public utility, you now save 855 dollars in electricity costs at an electricity price of 30 cents (2,850 * 0.3).
By feeding the remaining 1,900 kWh (4,750 - 2,850 kWh) into the grid, you earn an additional 152 dollars per year (1,900 * 0.08) with the aforementioned feed-in tariff of 8 cents. This results in a total annual saving in electricity costs of 1,007 dollars. The PV system and the residential battery backup would pay for themselves within about 12 to 13 years. Again, we have not taken into account the annual maintenance costs.
What Should I Pay Attention to When Buying and Using Solar Electricity Storage Batteries?
Due to a better efficiency and a longer lifetime than lead batteries, you should buy aresidential battery storage with lithium-ion batteries. Make sure that the storage unit can withstand about 6,000 charging cycles and get offers from several solar battery suppliers. There are considerable price differences even among modern storage systems.
You should also install the electricity storage battery in a cool place inside the house. Ambient temperatures above 30 degrees Celsius should be avoided. The devices are not suitable for installation outside the building. You should also discharge the electricity storage unit regularly. If they remain under full charge for a long time, this will have a negative effect on their lifespan.
If you follow these instructions, the residential electricity storage batteries will last much longer than the 10-year warranty period usually given by manufacturers. With the right usage, 15 years and more are realistic.
About BSLBATT Lithium
BSLBATT Lithium is one of the world's leading electricity storage battery manufacturers and a market leader in advanced batteries for grid-scale, residential battery storage and low-speed power. Our advanced lithium-ion battery technology is the product of over 18 years of experience developing and manufacturing mobile and large batteries for automotive and energy storage systems (ESS). BSL lithium is committed to technological leadership and efficient and high quality manufacturing processes to produce batteries with the highest levels of safety, performance and reliability.