Earlier residential solar panel systems did not have an easy way to add storage to your solar panel system. More and more residents are adding solar panel storage batteries. Tesla residential solar panel solution bundle includes a battery bank.
Solar panels have peak electricity generation during the day and most residents have peak consumption in the evenings.
Solar panel systems without battery storage had only 1 option in handling excess power generated and that was to sell it to the electric company. This is still an option and not a bad one. The benefit of battery storage is that you save energy during peak generation and you use it during periods of low or no generation (i.e. storms, electric grid down or nights).
Some local utilities companies feed-in tariff agreements pay for energy sold to the grid on a ‘deeming’ method. I will cover this in detail in a future post but it simply means there is a calculation done at time of installation and assumptions on how much you will sell back. If you have a battery bank you are likely to sell back less, consume more, than a home without a battery bank. This alone can make the price of a battery bank worth while.
Battery Backup or Standby Generator Alternative
The average cost to install a standby generator is between $8,000 and $20,000. This doesn’t include the annual cost of maintenance. A home with solar panels and a battery bank can get the same benefit of a backup generator, plus other benefits for roughly the same costs. A solar panel battery bank system runs between $7,000 to $14,000 to install.
You should consider what the amount of utility outage you can expect and then size your battery bank to accommodate it assuming some level of solar generation and battery utilization.
The bottom line is a battery bank will add cost to the installation but you will use more of your electricity making you less dependent on the utility company.
There are a few key considerations in determining if solar panel battery bank makes sense and we will include it in our upcoming financial analysis. Things that we will factor in include:
- Does you utility provide pay full retail for energy you sell back?
- How often and how long do outages typically last.
- Does you power utility have a time-of-use pricing system where you pay different prices and different times
- How critical is uninterrupted power to you.