Solar Battery Size Requirements
To determine the size of the solar battery needed for your system, you need to consider your power consumption patterns, when you need the battery to operate, and the reasons for the purchase (e.g., backup during a blackout, lowering your electricity bill, becoming fully independent from the power grid).
If you buy a solar battery that’s too small, it will not hold enough charge to last until the sun rises the next day; however, if you buy one that’s too large, you are effectively paying for something you won’t use.
Why is size more important than brand when choosing your solar battery?
Your solar battery size is defined in terms of kilowatt-hours (kWh). This number indicates how much energy can be stored in your battery.
A good analogy is the comparison of a water tank. The size of the water tank is the more influential factor when purchasing, rather than the water tank’s brand. The most important consideration when selecting between various sizes of solar batteries is how to properly match the size of the battery to your home’s actual energy consumption, rather than simply making an estimate or guessing.
Evaluating your Energy Usage
To determine how large a solar battery you need, you need to know how much energy you typically consume in a single day.
The typical profile for an Australian household is between 15-25 kWh. Those with larger families, homes, or appliance usage need to calculate higher usage levels based on their size and daily routine. Typically, your utility bill will detail your daily average energy consumption. This figure serves as a starting guideline for your system.
Determining When You Use The Most Energy
In contrast to the total energy required daily for your home from the grid, batteries will generally fulfill only those energy requirements associated with the time between sunset and first morning light.
This means that if your household primarily consumes energy during the day (i.e., while the sun is shining) then smaller batteries can adequately supply your power needs for the entire evening hours, because during this time you will already have excess power generated by your solar panels.
If your household generates electricity primarily after 5pm , a larger battery will likely be needed to cover the energy that powers your electrical device usage in the evening.
Where is your energy going?
To reach an accurate conclusion about the size of the battery that you will need, try to determine what your household’s actual electric consumption patterns are. To help you evaluate this decision, ask yourself the following questions:
- How often do you use air conditioning during the evening hours?
- How often do you cook electric food on most evenings?
- Do you plan to charge an EV vehicle at the end of the evening?
- Will you need to have power available to cover short periods of blackouts?
If you answered yes to any of these questions, you’ll want to be sure to select batteries that are larger than average for your household electricity consumption requirements.
Solar Battery Systems
Here is a general overview of different types of solar battery systems available and which homes are best-suited for each type of system.
Small batteries (5-7 kWh)
Small batteries (5-7 kWh) are best suited to homes with low evening electric usage or homes occupied by shift workers etc. who leave their homes overnight.
Most homeowners have more than enough excess energy generated from their solar panels after all their electric appliances are switched off to fill a small battery’s energy storage capacity. Examples of appliances that are most frequently powered by 5-7 kilowatt-hour batteries would include lights and entertainment equipment used in the evening.
Not many homes will be powered 24 hours a day with a battery. However, batteries such as the Sigenergy Sigenstor will take soften the blow of peak energy power prices.
Medium sized batteries (between 8 and 13 kWh)
Medium sized batteries (between 8 and 13 kWh) are considered the best option for most households. Families with children at home, those working from home, and those wanting reliable electric service during the evening hours will benefit from a battery in this size range.
With these types of batteries, you will generally maintain your standard power usage between 7pm – 7am of the following morning. Many of the more modern systems that are installed within homes today fall within this size range.Examples of these batteries include:
Larger batteries (14 kWh+)
Larger battery systems such as Midea Hiconics batteries will generally suit households that require a much greater amount of electrical power during the evening hours. Households that have an electric vehicle or are otherwise planning to have a lot of backup power in their home will generally be looking for a battery that is larger than 14 kWh.
Generally, the use of larger system batteries offer great flexibility in terms of possible future upgrades, such as adding additional panels or connecting more batteries to help create a larger overall system.
The larger system will provide a homeowner with the flexibility of being able to use the battery for short-term and long-term backup situations as needed.
What Size Solar Battery Will I Need For Blackout Purposes?
This question is answered less by the size of battery, instead the design plan of a battery is what’s important in this situation. Enabling you to utilise more stored capacity than you might think.
When considering what size battery you will need for backup purposes, a significant number of homeowners will look at only needing to power the lights in their home, refrigerator, computers and possibly even their internet service. If this is all you are concerned with, having backup battery power for, you don’t require a massive battery system. You need a smart design, along with the appropriate circuit connections to the battery, to sufficiently power your essential appliances in the event of a blackout.
On the other hand, if you desire a full home backup system including cooling systems, larger appliances, as well as the ability to operate multiple appliances at once, a substantially larger battery will be needed and potentially one that requires multiple battery units to provide sufficient power for the longer term.
Battery Compatibility With Your Solar System
A top of mind consideration when deciding on a solar battery is whether or not it is compatible with your current solar system. How much energy is your solar system producing and can your desired battery keep up with this?
While it seems logical to assume that if your solar panels produce 20 kWh per day, you would purchase a battery capable of storing 20 kWh, the reality is that, overcast weather days and during the winter months, you would likely only see a fraction of this production.
Therefore, a battery’s size should correspond to the average excess amount of kilowatt-hours (kWh) you produce during the year, not simply based on your highest production days in the summertime.
Additionally, the plans that you have for your solar power system and battery storage should also be taken into consideration prior to deciding upon a battery’s size.
Don’t Let Battery Decisions Limit You
When selecting a battery for your home, do not be constrained by the idea that you will never be able to change it later.
Most battery systems today are capable of incorporating an extra battery storage unit if needed in the future. Additional batteries will be beneficial for homeowners who may have plans to purchase an electric vehicle (EV), to invest in additional solar panels and/or are moving towards heating and/or cooking via a fully electric system.
By selecting a battery design that can expand with the homeowner’s future requirements, a lot of frustration can be avoided in the future.
So, what size solar battery do I require?
The answer is that it varies for each individual.
As a general rule of thumb, today, the average Australian household that has balanced its energy consumption between evening usage and daytime energy production will find that it is adequately satisfied with a size battery in the medium range (between 8 and 13 kWh).
For homes that have a considerable amount of electrical devices being used, and those that may not require as much energy consumption, the ranges will be different. The appropriate battery size for each household corresponds to their habits..
Find Your Ideal Battery With The Experts
If you are interested in storing energy for your home, talk to someone who has experience sizing batteries daily.
At SunEnergy we are experts in everything solar related, prepared to design solar and battery systems based on the actual power flow through your household. Helping you navigate when energy is consumed and how the battery storage can work in conformance with your solar system without unnecessary spending.
For an easily understood, explained and friendly process contact SunEnergy today. We’ll make sure you obtain an energy generation and storage design that is catered perfectly to your household’s energy consumption.
