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  • 1.  Is Storage Worth the Investment?

    Posted 12-05-2022 02:08 PM
    Hello, everyone!

    So, as I research further and further into Solar Technologies, I find myself asking questions which I cannot answer myself. While I have my personal opinions on various subjects, it is always a good idea to get some feedback from others with similar passions for renewables such as solar energy.

    After learning aspects of Solar PV system design, it is abundantly clear the major heavy hitter in terms of finances is the inclusion of storage with solar systems (or renewables of any kind for that matter). While grants and rebates are present in most states (along with the Federal ITC rebate at 30%) help alleviate the financial burden, I was wondering how this community felt about the inclusion of storage methods with solar systems. While I feel it would be ideal, there are some situations in which the inclusion of storage could be too financially debilitating for a current investment, especially since battery life of some of the more economical versions of storage don't hold up to the system's array/inverter life.

    Simple version of my question: Is storage worth the current investment in your opinion? Should it be a consideration for MOST people looking to purchase a solar PV system?

    Thanks for your input!

    Nathan Freeman
    ASES Technical Divisions
    Milford DE

  • 2.  RE: Is Storage Worth the Investment?

    Posted 03-25-2023 02:34 PM
    Edited by Tom Thompson 03-25-2023 02:35 PM

    Hi Nathan - people get storage for back up when the grid goes down, which is generally not often, and there is no payback for storage beyond the inconvenience of being without power, internet, etc.  Storage is more expensive than fossil fuel generators, which people tend to get for backing up the grid.  The one exception to this general rule is california which recently passed Net Energy Metering 3.0. NEM3 reduces the export payment to homeowners who put PV electricity on to the grid by 75% and also places PV home owners on a demand based, variable tariff structure which makes importing power from the grid more expensive.  The emerging solar strategy is to install a small batter system that is filled with PV power during the day and discharges that power in the evening to serve load and minimize the power being imported from the grid. In this situation, storage will have a payback.  Many expect utilities east of california will come forward with similar proposals.  

    Tom Thompson
    National Sales Manager
    Greentech Renewables
    Pelham MA

  • 3.  RE: Is Storage Worth the Investment?

    ASES Life Member
    Posted 03-27-2023 09:44 AM
    Hi Nathan,

    I have a different take than Tom did to your question "Is storage worth the current investment in your opinion? Should it be a consideration for MOST people looking to purchase a solar PV system?"

    Just as the appropriate PV system type and size depends on local factors, I think storage also depends on a number of specific local factors related to how your utility charges for power (typically, is true net metering available? and if yes, do you expect it to remain available?  If not, then it is definitely worth considering storage).  

    While I don't see storage today as generally cheap enough that it should be installed with every PV system, I definitely see industry pricing moving in that direction within 5-10 years.  Many utilities outside of a few "progressive" states do not offer true net metering--while many that do are aggressively working to roll it back.  

    In locations without true net metering, utilities typically offer re-imbursed generation rates significantly lower than the rate they sell to consumers.  I think it is a roughly 8 cent/kWh differential at the co-op in northern IL where my parents live;  ~11cents when the co-op sells and it buysback at ~3cents per kWh.  Given this starting differential, not to mention how other rate setting policies (like demand charges) can impact the overall bill, and the strong likelihood utility rates will rise in the future, I'm advocating that my parents install PV with storage.  Now how much storage to install will depend on a different set of assumptions/calculations related to their specific energy use patterns, but some amount of storage seems almost necessary.

    Daniel Simon

  • 4.  RE: Is Storage Worth the Investment?

    ASES Life Member
    Posted 03-27-2023 09:46 AM

    Yesterday at noon my grid power returned after being off for around 20 hours, the result of a severely windy Saturday (3/25) here in NE Ohio.   I have two battery backup systems (one supports a wood-fired hydronic heating system that cannot be allowed to freeze in winter) and they got me through this period easily.  I also have grid-tied PV that helps recharge them, but the total systems' cost probably doubled because of the storage.  Is it worth it?  I did all the install work myself, including obtaining permits, and my answer would be yes.  But I'm lucky to have the ability and wherewithal to do it myself, and although grid outages are infrequent where I live, I think it was worth it.  My situation isn't typical, though.

    Mike Curran
    Retired EE