How To Store Renewable Energy
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When it comes to powering your home with renewable energy, it’s easy to picture the endless sunny days, a steady wind, or that constantly running stream.
But, we all know that life isn’t always so picture perfect. Eventually, we get cloudy days, and the sun does have to down every night. The wind is going to die down, and a summer drought might dry up that rushing stream in your backyard. For many people, this is a major stumbling block to using renewable energy.
If you’re thinking about using one of these sustainable energy sources to power your home, then you might be wondering how to store that renewable energy for those times when Mother Earth isn’t cooperating.
Fortunately, there are options to ensure you’re not wasting that precious energy your home is producing.
How To Store Renewable Energy
When it comes to storing renewable energy, we have to have batteries. Lots of them. They’re called storage battery banks.
But what size, and how many, largely depends on the size of the system and how much power you’ll actually need to store.
Most experts agree that you should have enough batteries to store at least twice the amount of power you use in a day. And, many homeowners have systems that will store 3-6 days worth of power.
Home Power Magazine reports that batteries are “the weakest link” in most renewable energy systems. Why? Because setting up an RE storage system is no easy task, and it’s incredibly easy to make a wrong choice here. Even professionals get it wrong sometimes, leading to dangerous, expensive, or hazardous mistakes.
There are several types of batteries you can consider for your renewable energy system:
- RV/Marine Batteries- These batteries are only 12 volt, and can only be used for very small systems. They don’t hold a lot of power, and don’t stand up well over continuous charge/discharge cycles.
- Lead Acid Deep Cycle Batteries- Deep cycle batteries are designed to be stored, and then drained deeply (as much as 50%). They are very effective for renewable energy systems because they last much longer than RV/Marine batteries. It’s important to realize that these are very different than car batteries! Car batteries have the ability to release their energy quickly (like when the car starts), and then get rapidly recharged from the engine. They do not hold up well to the slow recharging of a typical RE system.
As you can probably tell, most people with a renewable energy system are going to use a lead acid deep cycle battery. And, there are two different types of deep cycle batteries:
- Flooded Lead Acid Deep Cycle Batteries- According to AltStore.com, flooded batteries are the least expensive deep cell battery, and they also last the longest. But, because of the off gassing that occurs when the batteries are recharged, they must have distilled water added to them on a regular basis. So, they require regular maintenance.
- Sealed Deep Cycle Batteries- Sealed batteries don’t last as long as flooded batteries, but they don’t require as much maintenance, which means they work better for remote locations. They cost more, but can be used in the battery bank in any direction (upside down, on their side, etc.), which means they’re more flexible.
Many people who have renewable energy systems stay connected to the grid so that they don’t have to have any kind of storage system. Instead, they sell their excess energy back to the power company, which is called “net metering”.
The advantage to net metering is that you don’t have to worry about investing in a battery storage bank, or deal with the maintenance that inevitably comes along with it. And, staying connected to the grid means that your excess energy can actually earn you money.
On the other hand, the disadvantage is that you have to stay connected to the grid. Many people prefer to be entirely independent, so this option is going to a be personal decision for you.
According to Home Power Magazine, there are several problems that commonly come up with battery bank systems.
- Improper Charging- If your batteries are kept in a low state of charge, you’ll ruin them within the first few years. Home Power Magazine suggests that batteries should receive a complete charge at least once per week.
- Improper Sizing- Home Power Magazine recommends that when you’re setting up your battery bank, to overestimate how much storage you’ll need. After the first years it’s not effective to add more batteries, since they work best as matched set.
- Improper Maintenance- Batteries corrode. They need water. They’re sensitive to cold. If you don’t take care of your batteries, they’re not going to last. Any battery storage bank takes regular care and maintenance if it’s going to last.
It’s important to do your homework before making any purchases for your battery storage system. It’s extremely important that you buy the right battery, and the right amount, for your specific system. This is an area where things can easily go wrong, leading to some expensive mistakes later on down the road!