To move forward in the technological race, embracing renewables is important; solar battery storage is one example. Not only is it environmentally friendly, but it also lowers our dependence on fossil fuels. This enables homeowners to save electricity for later use, especially for power outages.
The problem with lithium-ion batteries is that their improper maintenance or installation can lead to thermal runaway. Lithium batteries employ a battery management system (BMS) for smooth operation within fixed charge states, voltage, and temperature. These factors must be adjusted with the battery's aging since its requirements change over time.
You should know that the risk of thermal runaway is very low, but we will discuss this topic with great caution. This is because homeowners should know everything that can happen with a battery and be prepared for anything unexpected.
Thermal Runaway
In this process, the battery’s heat generation is higher than the heat released. This can take place in energy storage systems that employ lithium-ion technologies. However, it’s more common in large storage capacity installations like utility or commercial scale applications.
It’s a very rapid process, and if it isn’t handled quickly, the rising internal battery temperature can damage the solar battery or even start a fire. It’s hazardous, scary, and expensive, but noticing the early warning signs can assist you in preventing expensive home battery replacements, which will ultimately ensure your solar panel batteries’ proper working.
Causes
The three types of battery abuse are:
Mechanical Abuse:
Any physical damage done to the battery can increase the internal heat of battery cells and emits harmful gases. This is rare and can be avoided with careful installation and handling of the batteries.
The age of a battery can also lead to thermal runaways. Batteries degrade over time and require different charging and operation parameters, and if not adjusted properly, this can lead to higher internal heat.
Electrical Abuse:
You should provide an optimum flow of current and voltage to a battery such that it can handle that charge. Excessive charging or charging over the needed voltage can damage a battery's life. This leads to increased internal heat generation and, ultimately, thermal runaway.
Thermal Abuse:
Your topmost priority should be the temperature of a battery. It's essential to handle the temperature of a battery, especially when charging. Lack of proper airflow and air conditioning can increase the temperature of the cells.
Any temperature above 77° F (25° C) will increase the likelihood of thermal runaway.
You can easily avoid thermal abuse by placing batteries in some place where the temperature can be controlled. This can be an entry hallway closet or a garage.
The Process
The main reasons for thermal runaway are:
- High ambient temperature.
- High charging current.
Lithium-ion batteries are overcharged if the charge exceeds 10% of the battery's amp-hour (AH) rating. Overcharging increases temperatures, overheating the battery and breaking or melting its outer casing. Room temperature is the normal temperature for solar batteries. Anything above that and thermal runaway is possible. Here’s how it happens:
- Increased charging current raises the battery’s temperature.
- The internal resistance drops due to increased charging current and temperature.
- The lowered internal resistance allows more current, which generates more heat.
- A positive feedback loop will destroy the battery if the current isn’t monitored and cut off.
The reason for this is that heat generation is more than heat expulsion. Once a battery cell experiences thermal runaway, other neighboring cells will have the same high temperature that spreads to other cells, essentially creating a domino effect. Thermal runaway can cause bulging and overheating of a battery, so much so that its outer casing is breached.
Signs Of Thermal Runaway
The three telltale signs of thermal runaway are:
- Overheating.
- Inconsistent charging current.
- The smell of rotten eggs.
The emanation of hydrogen sulfide from your battery is a warning that the battery is compromised. This gas gives off a pungent smell of rotten eggs. If you smell this, you shouldn’t charge your battery and immediately contact a solar professional.
Variations in current or overheating will indicate that your battery is compromised or might be on the brink of thermal runaway. If you detect all of this early, the damage could be reversed. However, if you don’t, the only viable solution will be to remove the damaged battery packs and insert new ones.
Prevention
Even though thermal runaway is rare, unless there is improper charging, short-circuiting, or abnormal temperatures, it’s essential to detect it early or even avoid having it in the first place. Modern energy storage systems have built-in mechanisms to avoid thermal runaway too.
However, it’s always a possibility, and there are some preventative measures you can take:
- Check the battery regularly for any problematic cells or warning signs.
- Maintain a constant temperature near the room temperature during charging.
- Separate an overheating battery from the other batteries, so the thermal runaway doesn’t spread.
- If the temperature rises above a specific limit or starts to overheat, immediately unplug it from the power source.
The Future
Lithium-ion batteries have great demand nowadays, and these batteries are leading the energy storage market. The solar energy industry also prefers them. These batteries have a high energy density, longer lifespan, slower discharge rate, and lower price. They’re also scalable and easy to maintain.
The future for these batteries is bright since they’ll be used in large-scale applications and only increase in supply and demand. Future batteries will have an even lower risk of thermal runaway. But right now, we must be careful of the thermal, electrochemical, physical, or mechanical harm that can cause thermal runaway.
This is why it’s in the best interests of everyone to ensure a safe experience by having a licensed solar professional install your batteries. Regular preventative maintenance of your solar batteries and replacing damaged batteries with new ones can help prevent thermal runaway.
How Many Solar Panels Do I Need to Power My Home Appliances?
If you’re considering buying or have selected which solar panels you want to buy for your home. You might be thinking about the number of solar panels needed. The answer to this isn’t straightforward, but it depends upon your electricity consumption.
Knowing how much energy you consume and how much energy one solar panel can provide, you can calculate the number of solar panels needed for your home. This article will help you calculate your energy consumption and the number of solar panels needed for your home.
Calculating The Energy Consumption Of Household Appliances
The easiest way of calculating power consumption is starting with the biggest appliance and making your way down from there. The unit for power consumption is kilowatt-hours (kWh). This will depend upon the type, device, time in use, and size of the appliance.
The two ways that you can use to determine how much power each appliance needs are:
Consumption:
You can use a smart plug, tracking monitor, or an energy monitor to track an appliance's consumption over time. After writing this number down, multiply the energy consumption by the expected operating hours. Do this for all appliances and add the numbers to your total energy consumption.
Power Rating:
The power rating is visible if you look closely near the power cord. This will be in amps or watts. If the unit is amps, check the circuit's voltage in your home (typically 120V). Now, you can apply the formula: amps x volts = watts (W). After this, multiply the hours of operation for that device on the day by its wattage and then divide the result by 1,000 to find kilowatt-hours/day.
Solar Panels Needed
This depends on two things:
- Peak sun hours.
- Your electricity consumption.
Increased electricity use will require more solar panels, and increased peak sun hours will need fewer solar panels.
This number is estimated by looking at three factors:
- Yearly electricity consumption.
- Solar panel rating.
- Production ratio.
Yearly Electricity Consumption:
Measured in kilowatt-hours (kWh), this is the amount of electricity used to power your home in a year. It depends on your devices' energy consumption and how often you use them.
Solar Panel Rating:
This is the power output of a specific home solar panel when the weather conditions are ideal. It is measured in watts (W). The calculations below will be using 350W as an average solar panel rating.
Production Ratio:
This is the ratio between the actual size of the system (W) and the estimated energy production of the system over time (kWh). It fluctuates due to the peak solar hours of different regions. We recommend that you do calculations in the 1.3-1.6.
You can estimate the number of solar panels needed by using the above values with the formula: Annual Electricity Usage / Solar Panel Production Ratio / Solar Panel Rating = Solar Panels.
10,715 kW / 1.6 / 350 W = 20 panels (Areas with More Peak Sun Hours)
10,715 kW / 1.3 / 350 W = 24 panels (Areas with Fewer Peak Sun Hours)
Decreasing Power Consumption
The numbers listed above are just examples. You should only refer to them as examples and calculate the number of solar panels needed for your home—also, factor in the usage times of different appliances.
After calculations, you may find that your energy consumption is so high that you need a lot of solar panels. However, you don’t need to worry about this since there are ways to reduce your energy usage habits:
- Try caulking any cracks, air leaks, or window frames.
- Installing a programmable thermostat will make your HVAC system work more efficiently.
- Instead of using the stove or oven, opt for slow cookers and microwaves.
- Don’t overload your fridge.
- Use cold water in the washing machine and run it on full loads.
- Use energy-hungry appliances during the day in the winter and at night during the summer.
- Switch from light bulbs to LEDs to save even more money.
- Use power strips for chargers and electronics if needed, and turn them off when the devices aren’t in use.
- Turn off lights and water when not in use.
- Buy ENERGY STAR-rated appliances for the most energy-efficient options.
Powering Home Appliances With Solar
It’s very easy to calculate the power needed for your home by summing the energy usage of every appliance in your home and putting the total value into the formula given above. This way, you’ll get to know the number of solar panels needed for your home. Solar panels provide you with clean, renewable energy. Another way of estimating your energy consumption is by reviewing your past utility bills to determine your home's expected power consumption.