Should I use a battery or Generator for home back-up?

Everyone knows how great solar energy is. But, do you know that if your power is out your solar will not produce electricity for you? That is correct. If the grid is down, so is your solar. With increasing wildfire dangers, and PG&E doing Public Safety Power Shutoffs (PSPS) having a backup power source has become a necessity for large areas of California. Luckily, there are lots of options available to power your home when the grid is down. So, do you go generator, or battery backup?

What are Your Goals?

The first step when looking at a backup power source is to decide what your goals are. How much of your home do you want to backup? Do you want to power your home as if the grid was still on? Do you just need to power the basics? Maybe you or a family member has a medical condition that requires power available all the time. Think about how often you need backup power, and for how long. 

Are you making this purchase while installing solar? If so, your solar, and battery or generator will most likely qualify for the 26% federal tax incentive. That is a 26% rebate of the total cost of the system. There are limitations, so reach out to your CPA to confirm first. In addition, batteries qualify for California’s Self Generation Incentive Program (SGIP) rebates. The process can take a while, and there is no guarantee, but you can potentially get a few thousand dollars in rebates for your battery storage.

Generator

Generators are the go to solution for a lot of folks. They come in all kinds of sizes and price points. You can buy them at any hardware store, which makes it a popular solution. The smaller sized units (2-10kw) will run about $1,000 or less making it by far the most economical solution. However, they take some work on your part. You will need to find an electrician to install a transfer switch to safely power your home. You have to manually hook it up and start it. You also need to keep it fueled up. In addition, they can require maintenance to the fuel system when left in storage that can be a major pain.

A turn key option is to install a whole home generator. These units are hard wired to your home and are fully automatic. They sense when the grid is down and fire up instantaneously. They generally run from 10kw-30kw and generate enough power to run your entire home as if the grid is on. They do come with a higher price tag, but the ease of use may be worth it. They can use a lot of fuel if you are running large appliances around the clock.

Pros: 

• Different price points available ranging from $1,000 to $20,000
• Can provide plenty of power for your entire home
• Can be purchased at any hardware store
• Larger units are fully automatic

Cons:

• Can be noisy
• Emits emissions
• Burns fossil fuel, either gas, propane, or diesel
• No state rebates available

Battery

Lithium Ion batteries have drastically changed the battery backup market. They are by far the most energy dense chemistry available for storing electricity. Thanks to their wide use in electric cars, lithium ion applications have skyrocketed, while the price has come down considerably.  What was impossible just a couple years ago has now become commonplace. Batteries are great for backup power during a power outage. As with generators, they come in all kinds of sizes ranging from 3kw to 20kw. Multiple units can be linked together to get much higher storage. 

A backup battery is a great addition to your home solar system. It allows you to store the energy you created on-site to use after hours (peak use rates). This means a battery can provide value to your home every day, not just when the power is out. When there is a power outage, a battery allows your solar panels to continue operating, further adding value to your system. Your solar panels will recharge your battery for continued use while the grid is down.

There are some tradeoffs with batteries compared to generators, so you really need to be clear of your goals when making the purchasing decision. In general, batteries provide less power for your home than an equally sized generator can (power and cost). However, you never have to fill a battery with fuel like you do a generator, there is very little maintenance, and there is zero noise to worry about.

Pros: 

• Quiet operation
• No fossil fuels, no emissions
• Allows solar panels to operate while the grid is down
• Offsets peak use energy consumption further adding value to your system
• State and federal rebates may be available

Cons:

• Less power than an equally sized generator for power and cost
• Shorter lifespan than a generator install

What is Best?

Deciding what is best for your home all depends on what your goals are. Are you in a high fire area with frequent PSPS power outages? Do you or a family member have a medical condition that requires backup power all the time? Are you combining backup power with a solar array? There are lots of factors to think about when deciding what is best for your home.

Some home owners choose to have both options. You can use the solar and batteries to offset your evening eletrical usage, and use a generator for extended power outages. This is a great solution if you live in rural areas and mountains with frequesnt outages due to weather and fire danger. The downside is cost. It can be prohibitive for some home owners. There are state and federal rebates to help, as well as great financing options available. Reach out to us if you have questions, or would like to see a free quote for your home solar and or power backup.